Climate Change

Why remembering the Big Thompson Flood of 1976 matters today

Rachel Sauer — Wed, 29 Jul 2026 15:44:28 +0000

Why remembering the Big Thompson Flood of 1976 matters today Rachel Sauer Wed, 07/29/2026 - 09:44

A cabin lodged on a private bridge just below Drake, Colorado, following the Big Thompson Flood in 1976. (Photo: W.R. Hansen/U.S. Geological Survey)

Bradley Worrell

CU �ֲ��ý Natural Hazards Center Director Lori Peek says there are still lessons to be learned from the devastating flash flood, 50 years later

Fifty years ago this week, a beautiful summer evening in Colorado ended in catastrophe.

On the night of July 31, 1976, a powerful thunderstorm stalled over the Big Thompson Canyon west of Loveland, unleashing a torrential rainfall in a matter of hours. The resulting flash flood killed 144 people and became the single deadliest disaster in the state’s history.

For Lori Peek, professor of sociology and director of the Natural Hazards Center at the �ֲ��ý, the flood’s most important legacy may be the lessons that emerged from it—and the realization that those lessons still require attention today.

Lori Peek is a CU �ֲ��ý professor of sociology and director of the Natural Hazards Center.

“Anniversary events like this one are so important because they serve as moments for communities to come together and reflect upon what was lost, what we’ve learned and what we still need to do to become more resilient in the future,” she says.

A perfect storm of human, environmental and built factors

While the Big Thompson Flood is often remembered for its meteorological extremes, Peek says that disasters are never caused by nature alone.

“One of the things we say in this field of study is that there are natural hazards, but there’s no such thing as a natural disaster,” she says. “Every disaster has a human component.

“There are, of course, natural hazards—floods, fires and tornadoes—but what turns them into disasters is the collision between vulnerable built environments, vulnerable human systems and the natural environment. That’s what creates a disaster.”

In the case of the historic Colorado flood, Peek says several factors converged to maximize the damage. These included:

Storm stalled: Rather than moving through an area as storms tend to do, the storm that evening stalled over the canyon, dumping more than 12 inches of water in just over four hours. “It was almost like pouring water into a bowl,” Peek says.
Rapid water rise: The floodwaters rose with astonishing speed, leaving many people trapped in cabins, automobiles or low-lying areas before they understood the danger.
Geography: The canyon’s steep walls funneled water into a narrow corridor, placing people in homes, hotels, campgrounds and vehicles along the river in harm’s way. “The topography played a major role,” Peek acknowledges.
Nightfall: The storm struck after dark, when many people were sleeping. Also, of those who were awake, some could not see or sense the danger.
Cars: Many victims were in cars—either trying to flee the storm or parked near the river. “The people with the highest risk of dying were those who remained in their vehicles,” Peek says.
Timing: The storm struck during the final holiday weekend of the summer, when the canyon was crowded with campers and visiting tourists, as well as a mix of full-time and part-time residents. In total, it is estimated that about 2,500 people were in the canyon at the time.

“There’s also the human dimension—whether people understood the risk, knew what to do, could physically take action and could get to safety,” Peek says. “That complicated mix is what led to so many deaths.”

A cabin lodged on a private bridge just below Drake, Colorado, following the Big Thompson Flood in 1976. (Photo: W.R. Hansen/U.S. Geological Survey)

She adds that research conducted soon after the flood found that survival often depended upon a simple but critical decision: getting out and moving uphill.

“What the research on who survived and why—and who died and why—showed was that the key to survival was getting out … and literally climbing to safety,” she says.

She says that finding is one of the flood’s most enduring lessons.

A (new) sign of the times in 1977

Today, anyone who travels through Colorado canyons is likely familiar with the bright yellow signs depicting a person climbing uphill.

Peek says those signs endure because they communicate something essential: Survival depends upon taking immediate action.

Today, anyone who travels through Colorado canyons is likely familiar with the bright yellow signs depicting a person climbing uphill. (Photo: Brad Turner/KUNC)

“If you’re going to communicate risk effectively, the message has to be actionable,” she explains. “That’s why, even 50 years later, the signage remains so powerful. It tells people exactly what to do in the face of an imminent threat to life safety.”

Peek notes those climb-to-safety signs were the result of an August 1977 working paper by CU �ֲ��ý researcher Eve C. Grunfest, who interviewed dozens of flood survivors, first responders, emergency management professionals and others to learn what worked and what needed to be improved following the Big Thompson Flood. Grunfest studied under Gilbert F. White, a CU �ֲ��ý professor of geography who Peek says is widely considered the father of floodplain management and who founded the Natural Hazards Center in 1976.

The Natural Hazards Center was not established because of the Big Thompson Flood, as White was already in the process of founding the organization in 1975. However, Peek says the flood demonstrated why such an academic research center, dedicated to translating and sharing findings, was needed.

“The Natural Hazards Center was established because, at the time, a lot of research wasn’t making it into the hands of practitioners and policymakers,” says Peek, who was a graduate research assistant at the center from 1999 to 2005. She returned to CU �ֲ��ý in 2017 to serve as the center’s director. “The Natural Hazards Center was established to nurture the hazards and disaster research community and share information with those concerned with reducing disaster risk. That’s the work that federal agencies like the National Science Foundation support us to do, because the evidence shows that actions we take before disaster can save lives and prevent unnecessary harm and suffering.”

Comparing the floods of 1976 and 2013

In many ways, Colorado today is better prepared for flooding than it was in 1976, Peek says.

At the time of the 1976 disaster, emergency managers lacked many of the tools that are the norm today. Then, there were no cellphone alerts, no modern emergency notification systems, no social media networks and few of the sophisticated weather forecasting capabilities available today.

Peek says that weather forecasting has become more precise, at-risk communities have installed warning sirens and emergency communication systems can distribute alerts through many channels and in many different languages to serve diverse groups.

In the Big Thompson Canyon, some vulnerable structures destroyed in the 1976 flood were never rebuilt in the same locations.

“Portions of the built environment have been moved out of the highest-risk floodways and floodplains,” Peek says. “Some of the streamside motels, cabins and other structures that were destroyed in the flood were not rebuilt in those same vulnerable locations.”

When the Big Thompson River flooded again in 2013, Peek says it demonstrated both the value of those improvements and the continuing reality of flooding danger. While the 2013 flood caused massive damage and resulted in at least eight deaths, Peek says she believes losses would have been even worse without decades of investment in warning systems and flood mitigation.

Why some lessons go unlearned

Despite the progress made since 1976, recent disasters show that communities do not always implement best-practice safety measures. Peek points to the 2025 Camp Mystic tragedy in Texas, where children were swept away in a flash flood.

“They didn’t have an emergency action plan. They didn’t have sirens. They didn’t have timely cell phone alerts. They hadn’t moved structures in the floodplain out of harm’s way,” Peek notes.

Why do these failures persist?

Peek offers several reasons. While disasters can create “policy windows” for lawmakers and regulators to act, those windows close more quickly today due to short public attention spans, and consensus is harder to build in today’s age of political polarization, she notes. Additionally, even when guidance exists, people may not know where to begin or may be overwhelmed, she adds.

Still, Peek sees some reasons for optimism. New guidance documents from the Association of State Floodplain Managers provide step-by-step instructions for camps and RV parks to create emergency action plans and offer model ordinance language for lawmakers.

“That’s a good example of how progress happens,” she says. “Such guidance can help spur action.”

A state that has changed—and largely forgotten the storm

Meanwhile, back in Colorado, Peek says one of the bigger challenges in commemorating the anniversary of the Big Thompson Flood is that most Colorado residents—and nearly all of its visitors—have no memory of it.

“Fifty years is a long time,” she notes. “Most visitors would have no reason to know anything about the Big Thompson Flood unless they are particularly interested in disaster history.”

The Big Thompson Flood remains the deadliest disaster in Colorado’s history. By learning what happened, how lives could have been saved then and how lives can still be saved today, we have an opportunity to build a more resilient state.”

Even among residents, Colorado today is a relatively young state demographically. Many people weren’t alive when the flood occurred, and many didn’t attend school here. As a result, public awareness of flood risk remains low, Peek says.

“People are often surprised to learn that �ֲ��ý is one of the state’s communities most at risk to flash flooding,” she says.

At the same time, Colorado itself has changed dramatically since 1976. The state’s population has swelled from 2.6 million then to more than 6 million today. More people are hiking, camping and driving through canyons than ever, oblivious to the dangers that flash floods pose. And while technology has improved, many of those areas are still without reliable cell service, Peek notes. She adds that floods can strike with little warning.

Could a disaster like the 1976 Big Thompson Flood could happen today?

Peek’s answer is an unequivocal yes. That’s why physical signage, emergency planning measures, public education and land-use planning all remain essential—especially in a warming climate, she says.

“Risk isn’t static,” she says. “As we experience more extreme rainfall events, places that once weren’t considered high risk, or weren’t mapped as flood hazards, may now be vulnerable.”

Peek says it’s also why remembering anniversaries like the 1976 Big Thompson Flood still matters today.

“It’s so important to know our history,” she says. “The Big Thompson Flood remains the deadliest disaster in Colorado’s history. By learning what happened, how lives could have been saved then and how lives can still be saved today, we have an opportunity to build a more resilient state.”

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CU �ֲ��ý Natural Hazards Center Director Lori Peek says there are still lessons to be learned from the devastating flash flood, 50 years later.

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Top photo: Damage caused by the 1976 Big Thompson Flood (Photo: Maurice L. Albertson/Maurice L. Albertson Papers at Colorado State University)

The only way to make beef and dairy more climate-friendly? Stop producing it

Rachel Sauer — Tue, 28 Jul 2026 19:37:16 +0000

The only way to make beef and dairy more climate-friendly? Stop producing it Rachel Sauer Tue, 07/28/2026 - 13:37

Tiffany Plate

CU �ֲ��ý researcher Cliff Bueno de Mesquita and colleagues are showing why microbial solutions to livestock methane emissions reductions won’t stop beef and dairy’s environmental and health problems

By nature, cows are gassy creatures. But it’s not just the stink of their manure or their belches that are troublesome. The methane gas released by ruminants like cows (or bison, sheep or goats) also causes a lot of trouble for the planet.

That’s because methane is a potent greenhouse gas with a dramatically higher global warming potential than carbon dioxide. And ruminants raised for food account for 14% of global methane emissions.

Over the last decade or so scientists have been hard at work figuring out how to infuse cows’ feedstock with additives that inhibit methane-producing microbes. The process could reduce those methane emissions and potentially produce a more “climate-friendly” beef.

Cliff Bueno de Mesquita, who studies microbial ecology of permafrost and ancient sediments in the lab of ecology and evolutionary biology Professor Noah Fierer and in the Cooperative Institute for Research in Environmental Sciences, teamed up with other microbiologists passionate about environmental issues for this perspective piece. (Photo: Cliff Bueno de Mesquita)

Sounds like a win-win, right? A new perspective piece by Cliff Bueno de Mesquita (PhDEBio'19), a research scientist in the lab of ecology and evolutionary biology Professor Noah Fierer and the Cooperative Institute for Research in Environmental Sciences (CIRES), says otherwise.

“Even if you could decrease cows’ methane emissions by 100%, cows are still worse than plant-based agriculture for their land use, water use, pollution and impacts on human health,” says Bueno de Mesquita.

In their piece in the journal Sustainable Agriculture, Bueno de Mesquita and a team of microbiologist colleagues outline all the reasons that altering cows’ rumen microbes is a misdirected use of time, money and energy. “This is basically distracting from what we really need to be doing, which is reducing the ruminant population size,” he says.

This conclusion—that reducing the numbers of ruminants raised for food is the only solution to actually reducing livestock’s impact on the planet—has already been drawn by researchers around the world.

“There are a lot of great scientists working on this topic, with strong data sets that have been assembled with all of the evidence,” says Bueno de Mesquita.

Bueno de Mesquita and his colleagues cited 98 studies, to be exact, in their peer-reviewed opinion piece that re-emphasizes the personal and planetary benefits of a shift to a plant-based diet—and lays out exactly why rumen microbes are not the answer.

The problem with microbes

Some of the literature references cited in the piece are studies that have been done on the most common feed additives that have been studied for methane inhibition: seaweed and 3-nitrooxypropanol (or Bovaer). The research shows that the demonstrated efficacy of these microbes is extremely variable, with one review reporting a range of 10–63% reduction and another review reporting a range of a 4% increase to a 97% reduction.

Bueno de Mesquita and colleagues are also concerned that altering rumen microbes may lead to unpredictable health effects for the cattle, and may even decrease immunity to pathogens that could be detrimental to human health.

Another reason for concern? This method favors intensive beef production, where cattle are fed in feedlots rather than on grass (as is more likely to be the case in small-holder production). Not to mention that seaweed harvesting has its own inherent carbon emissions and environmental impact.

But Bueno de Mesquita’s team points out that even if none of these were issues, methane reduction does nothing to address potent nitrogen emissions or other emissions from the rest of the production life cycle (e.g., land use, water use, fertilizer, crop residues, manure).

Bueno de Mesquita and colleagues created this graphic to demonstrate how many ways livestock production can impact the environment and human health—and how only one of these impacts is reduced by trying to alter the microbes in the rumen with feed additives. (Graphic: Cliff Bueno de Mesquita and Ylenia Vimercati Molano)

Shifting people’s perspectives

The authors wrote the piece to be accessible to non-scientists in hopes of reaching as wide an audience as possible. “I want the public to be aware and to be skeptical of labels coming from the beef and dairy industry that are calling those products climate friendly,” says Bueno de Mesquita.

Of course, he also hopes that people will consider simply shifting to a plant-based diet in order to make their meals more climate friendly. But he knows that’s easier said than done.

“We're basically living in a ‘carnistic’ society where eating meat is perceived to be normal, natural and necessary,” says Bueno de Mesquita. “That's sort of people's default. So when they’re met with a proposal for a minor shift that challenges that, we know there's gonna be pushback.”

Two years ago Bueno de Mesquita and his co-authors published another paper documenting a push within CU �ֲ��ý’s Ecology and Evolutionary Biology department for more plant-based meals. “The PhD students were very hesitant to implement a dietary change, even though they know that it's going to be better for the environment.”

Even still, Bueno de Mesquita says the current perspective piece is getting a lot of traction. “I basically never get emails about my research papers,” he says. “But I've already gotten emails from multiple people saying that they agree.” He adds that even some leading microbiologists have posted it on social media.

That’s key to reaching the other audience Bueno de Mesquita and colleagues wanted to address: the microbiologists actually doing the research on rumen microbes in livestock feed, usually funded by the beef and dairy industries, he says.

“They're enabling the dairy industry to say, ‘Hey, we're doing this research. This is going to work’,” says Bueno de Mesquita. “Then the industry has an excuse to keep business as usual.”

Instead, he hopes that microbiologists and other scientists studying climate change will step up and speak with a unified voice about what needs to be done as a society. “It's very obvious,” says Bueno de Mesquita. “If you want to reduce methane from ruminants, you need to decrease the number of ruminants.”

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Top photo: Unsplash

Can evolutionary rescue help even long-lived species from going extinct?

Rachel Sauer — Tue, 09 Jun 2026 17:44:14 +0000

Can evolutionary rescue help even long-lived species from going extinct? Rachel Sauer Tue, 06/09/2026 - 11:44

Tiffany Plate

Two CU �ֲ��ý researchers are helping clarify how species’ populations with longer lives can still adapt to a changing climate

Our warming climate is leaving many plant and animal species with a choice: either adapt, find a new home or risk extinction. Fortunately, throughout the history of life on Earth, a concept called evolutionary rescue has stepped in to help species adapt to new environments and climates.

Evolutionary rescue is a biological process where natural selection favors the individuals of a species that carry genetics best suited to the new climate. These individuals are more likely to survive and reproduce and are therefore able to better propagate future generations to ensure survival of the species.

Scott Nordstrom (left) earned his PhD from CU �ֲ��ý in 2023 under the advisorship of Brett Melbourne. (right), professor of ecology and evolutionary biology (Left photo from Scott Nordstrom; right photo from Brett Melbourne)

For example, a smaller bat may be better able to weather a hot summer with multiple heat waves. Or a monkeyflower that's better able to retain water in its leaves may have a better chance of surviving a megadrought. These genetic anomalies help move the population toward survival, instead of extinction.

In the face of anthropogenic climate change, however, conservationists are worried that species with the longest life spans—like giant pandas, elephants, or sequoia trees, for which new generations take years to decades—will be too slow to adapt and avoid extinction.

A mathematical model developed by Scott Nordstrom (PhDEBio’23) proved that that’s not always the case, however. As part of his doctoral dissertation, Nordstrom, in partnership with Brett Melbourne, a �ֲ��ý professor of ecology and evolutionary biology, set out to determine just how true it was that long-lived species were resigned to their fate. Their findings were published in The American Naturalist in May 2026.

Their model contributes to conversations about conservation, especially when it comes to extinction concerns. “A lot of the more endangered species or the populations that are at higher risk of extinction tend to be longer lived,” says Nordstrom. “So, it's especially relevant for thinking about conservation.”

Shifting focus: From flour beetles to tortoises

Before taking on this project, Nordstrom and Melbourne had been working with colleagues at Colorado State University to understand the evolutionary rescue patterns of flour beetles, which live for about a month before a new generation is birthed.

“We found that genetic diversity of the population is really critical for allowing rapid adaptation to occur,” says Melbourne. “And that got us thinking about how things could be really different for longer-lived species.”

Large tree species, like the Giant Sequoia, can live for thousands of years, but are now more endangered than ever due to increased wildfire activity in the American West. (Photo: Pexels)

The researchers set out t try to understand how relevant their findings were to species with longer lives.

Experimental work tracking the genetic variations in generations of long-lived species was not possible, however, so the pair created the next best thing: A flexible mathematical model and computer simulations that would allow them to map out potential evolutionary patterns of these species.

For each simulation, they input a sample population into the model, using “good” environmental factors (i.e., the climate that they were already adapted to). Then they switched those factors to “bad” (i.e., a climate with warmer temperatures or less water).

“Each individual’s survival depended on how well it was adapted to its environment, so when the environment shifted from good to bad, survival was low and the populations started shrinking,” says Nordstrom.

“But because there was genetic variation within the populations, some individuals were slightly better adapted to the bad environment, and those individuals were more likely to survive and pass on their genes, allowing the population to adapt,” he adds.

When nurture beats nature

Through their simulations, Nordstrom and Melbourne were also surprised to find that long-lived species can experience a complicated evolutionary dynamic in which a population’s traits seem to decouple from their genetics. In these cases, some random environmental event has affected an organism's trait in a way that turns out to be an advantage in the changed environment.

For example, an American alligator might be genetically predisposed to weigh 600 pounds but actually weighs 400 pounds because environmental factors impeded its growth in early development. Perhaps the alligator was born in a drought year, when typical prey like fish and turtles were scarce.

Ultimately, that smaller alligator may be able to survive heat extremes better in a hotter climate, thus slowing the rate of population decline. And because they are long-lived (up to 50 years), there is a good chance that there will be multiple small alligators in a population at once, thus changing the composition of that population in a way that slows the rate of population decline, allowing adaptation time to catch up and prevent extinction, the researchers speculate.

Researchers have long thought that species like the American alligator, which can live up to 50 years, are less likely to benefit from evolutionary rescue to help them adapt to changes in the climate of their habitats. (Photo: Unsplash)

Interestingly, those chances are much less likely to occur to short-lived species like flour beetles. Nordstrom says that’s because their short life spans don’t allow for their non-genetic phenotypic variation (like that seen in the undersized alligators) to remain in the population as time progresses; instead, only their genes are passed on to their offspring, and their offspring will thus not inherit their size advantage.

“The flour beetles just mate once and pass their genes forward,” says Nordstrom. “Next generation, repeat.”

That means that natural selection occurring within a generation can be important for evolutionary rescue in long-lived species. Previously, it was speculated that only evolution between generations determined whether populations could adapt to new conditions in time.

“This process of rescue is one part evolution and one part demography,” says Nordstrom. “In the race of evolution versus demography, this definitely helps the demography because it slows down population decline.”

He adds that this will be surprising to researchers who have up to this point only considered the evolutionary component here. “But we showed that the demography is actually super important, too.”

While Nordstrom and Melbourne can’t say that all long-lived species will benefit from their demography, Nordstrom says it’s important for future researchers and conservation managers to know that evolutionary rescue is not out of the question for endangered species like pandas and bison.

“Maybe it's a little bit more complicated than we thought,” says Nordstrom. “But this is the first major study finding that it’s not necessarily true that slower generational turnover guarantees that adaptation and evolution will be slower.”

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Two CU �ֲ��ý researchers are helping clarify how species’ populations with longer lives can still adapt to a changing climate.

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Think all that plastic is being recycled? Think again

Rachel Sauer — Thu, 04 Jun 2026 21:19:22 +0000

Think all that plastic is being recycled? Think again Rachel Sauer Thu, 06/04/2026 - 15:19

A man walking amid plastic waste on the Maldivian island of Thilafushi. (Photo: Dying Regime/Wikimedia Commons)

Ellen Considine

A lot of ‘recycled’ plastic is being burned overseas—and causing widespread pollution linked to health problems

Picture a pile of trash the size of Manhattan and taller than one and a half Empire State Buildings. That’s how much plastic waste the world is predicted to be generating every year by 2050 if nothing is done to change course.

It’s easy to think of recycling as the solution, but the vast majority of plastic waste now ends up in landfills, or worse.

A large amount of plastic waste gets shipped overseas. In a new study, my colleague and I analyzed what happens when plastic waste is shipped to lower- and middle-income countries, where open burning is a common way of dealing with excess waste. The result, we found, is pronounced increases in toxic air pollution.

Ellen Considine is a CU �ֲ��ý assistant professor of geography and fellow of the Cooperative Institute for Research in Environmental Sciences (CIRES).

Plastic waste burning and health impacts

Between 40% and 65% of total municipal solid waste is openly burned in low- and middle-income countries, largely as a result of 2 billion people around the world having no municipal solid waste collection.

Open burning occurs both intentionally and unintentionally, the latter when open dump sites containing organic waste spontaneously combust due to heat generated as the waste degrades.

When plastic burns, it releases particularly toxic air pollutants. Fine particles can penetrate deep into people’s bodies, along with gases that include carbon monoxide, styrene gas and hydrogen cyanide. It also releases persistent organic pollutants such as polycyclic aromatic hydrocarbons and dioxins. These particles and gases have been linked to health risks ranging from respiratory and cardiovascular disease to cancer and reproductive and neurological disorders.

The ash from open burning can also contaminate soil and groundwater with persistent organic pollutants, heavy metals and other toxicants, creating more chances for people to be exposed to them through food and water.

The global plastic waste trade

Large amounts of plastic waste are shipped around the world – some to be recycled and much to simply be disposed of in landfills or incinerated. In 2024, 9.34 million metric tons of plastic waste imports were reported, according to the United Nations.

Where this exported plastic waste ends up has been shifting.

In 2018, China stopped importing plastic waste, causing the total amount of plastic waste moving among countries – at least through official channels – to drop dramatically. Between 1992 and 2016, China’s plastic waste imports made up 45% of global imports.

In 2018, the flow moved to other countries, largely in Southeast Asia but also other locations, including Turkey. In 2018, Indonesia became a net importer of plastic waste. The majority of this waste came from Western Europe, Australia and North America.

What happened to Indonesia’s air quality

We harnessed data from multiple monitoring systems, including satellite observations and cargo ship tracking signals, to understand where these plastic waste imports went and how much air pollution was released by openly burning this waste.

As of 2020, the World Economic Forum and Indonesia’s government estimated that 48% of Indonesia’s plastic waste is openly burned.

We found that particulate matter air pollution – of great concern for health – increased an average of 3.3% at the locations of large open waste dump sites in Indonesia after China’s ban in 2018-19 relative to expected business as usual, based on data from 2012-17. We found increases up to 1.68 micrograms per cubic meter.

Based on risk estimates from a global study of mortality associated with long-term exposure to outdoor fine particulate matter, this corresponds to an approximate 1.5%, 1.9% and 3.5% increase in mortality risk from chronic obstructive pulmonary disease, lung cancer and lower respiratory infections, respectively.

New constraints on the plastic waste trade

In 2021, Indonesia restricted the import of nonhazardous waste to 15 specific ports and in 2025 banned the import of plastic waste altogether.

A man walking amid plastic waste on the Maldivian island of Thilafushi. (Photo: Dying Regime/Wikimedia Commons)

In mid-2025, Malaysia followed suit, allowing plastic waste only from countries that have ratified the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and their Disposal – a treaty that the U.S. has never ratified.

For these bans to be effective, these countries must also find ways to contend with illegal plastic waste shipments and paper imports contaminated by plastic waste.

Meanwhile, negotiations for an international, legally binding treaty on plastic waste, started in 2022, have stalled. In mid-2024 the European Union did pass a new regulation on waste shipments, prohibiting exporting plastic waste to countries outside the group of wealthy countries in the Organization for Economic Cooperation and Development from November 2026 to at least May 2029.

The effectiveness of these and future policies at reducing air pollution – and other kinds of environmental degradation – can be evaluated using methods like ours.

Ways to reduce plastic waste

As of 2021, only 5% to 6% of U.S. domestic plastic waste was recycled, according to estimates from the advocacy group Beyond Plastics and Bennington College. It is now even harder to export plastic waste to other countries that could “recycle” it.

Part of the problem is lack of capacity: The Association of Plastic Recyclers estimates that current plastic reclamation facilities in the U.S. and Canada could at most increase their plastic recycling by 35% to 44%, depending on the type of plastic, leading to a total recycling rate of 7% to 9%.

Ultimately, both decreasing plastic use and increasing recycling will likely be needed to solve the problem. Beyond consumer choices, packaging reuse – creating packaging and return systems that put the same materials back to work – can reduce the need for new plastics.

Recycling experts call for harmonized design standards to help streamline processing and deliver higher-quality recycled plastics, as well as extended producer responsibility fees or taxes to raise the cost of producing products that aren’t recyclable. The fees can provide needed funding to scale up recycling and other programs to reduce generation of plastic waste.

Since 2021, seven states have enacted extended producer responsibility laws focused on packaging: Maine, Oregon, California, Colorado, Minnesota, Washington and Maryland. However, it will take time to see the effects. Colorado’s final implementation plan, authorized in 2022, was approved only in late 2025. The first payment of extended producer responsibility fees to the Colorado Department of Public Health and Environment are scheduled to begin in mid-2026.

Ultimately, reducing and better managing our nation’s plastic waste can help prevent global health harms.

Ellen Considine is an assistant professor in the CU �ֲ��ý Department of Geography whose research lies at the intersection of environmental change, health and wellbeing and data science.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

A lot of ‘recycled’ plastic is being burned overseas—and causing widespread pollution linked to health problems.

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Scholars apply economic analysis to ecological research

Rachel Sauer — Wed, 20 May 2026 21:25:35 +0000

Scholars apply economic analysis to ecological research Rachel Sauer Wed, 05/20/2026 - 15:25

“If you’re studying a natural area, you could get a permit and go sample all over, but you can’t do that in a city. Even if you get a permit, you can’t just go into people’s backyards,” explains CU �ֲ��ý scientist Asia Kaiser about the challenges of ecological research in urban areas. (Photo: Sandy Millar/Unsplash)

Rachel Sauer

In research published today, recent PhD graduate Asia Kaiser details how synthetic control methods estimated significant declines in bee observations when traditional analyses didn’t

Since it launched in 2008 as a UC Berkeley student’s master's project, the iNaturalist platform has been a source of both fascination and frustration for researchers.

The hundreds of millions of observations about the natural world logged by both professional and citizen scientists around the globe are a treasure trove of information about biodiversity. But is that data usable in research? The prevailing sentiment has veered toward doubt, skepticism or an outright “no.”

“I think the feeling has been, ‘Oh, because this data is just being collected opportunistically by nature enthusiasts and not in a standardized, rigorous way, it can’t be used in scientific research,’” says Asia Kaiser, who earlier this month earned her PhD in the �ֲ��ý Department of Ecology and Evolutionary Biology. “If you haven’t planned out data collection in advance, a lot of researchers hesitate to use it.”

Recent PhD graduate Asia Kaiser studied how synthetic control methods estimated significant declines in bee observations when traditional analyses didn’t.

There had to be a way, Kaiser thought, to tap into the vast cache of information logged into iNaturalist without sacrificing scientific rigor, especially data collected in urban environments. The answer, it turned out, lay in economics.

In research published today, Kaiser and co-authors Julian Resasco and Laura Dee, both associate professors of ecology and evolutionary biology, detail how combining iNaturalist records with synthetic control methods, originally used in economics, estimated a significant decline in bee observations in Philadelphia during the two years following Hurricane Ida in 2021, while conventional ecological analyses didn’t detect the decline.

“Basically, the inspiration for this project was thinking about causal inference in ecology,” Kaiser explains. “When we have observational data, can we actually use that to ask questions about drivers of biodiversity?”

‘You can’t just go into people’s backyards’

These questions dovetailed neatly with Kaiser’s research focus, which is bees—specifically, how human land use affects different insect groups and, consequently, the ecosystem services they provide in coupled human-natural systems. Among her research aims is understanding biodiversity in urban environments, improving the resilience of urban agroecosystems, increasing equitable access to fresh produce and promoting environmental justice in cities.

However, monitoring biodiversity and evaluating drivers of change in urban environments is confounded by several issues: “Cities are mosaics of land-use types, including parks, private properties, buildings, roads and industrial zones,” Kaiser writes in the paper. “As a result, sampling efforts can be complicated by permission and safety issues, and leaving unattended sampling equipment in the field brings a higher risk of theft, tampering and vandalism in cities.

“Given these challenges, measuring biodiversity in cities requires different tools and data streams than those used in natural ecosystems. Participatory science data is a promising solution for monitoring biodiversity in cities; cities are the land use type with some of the highest upload volumes of data to participatory science platforms, largely because upload frequency is strongly influenced by population density.”

Despite the abundance of participatory science data in platforms like iNaturalist, researchers have hesitated to draw from it, relying instead on randomized, controlled and replicable experiments to identify and estimate causal relationships. That kind of science, Kaiser says, becomes more difficult in urban environments due to sampling challenges and historical legacies that shape different neighborhoods, among other reasons.

“If you’re studying a natural area, you could get a permit and go sample all over, but you can’t do that in a city,” Kaiser says. “Even if you get a permit, you can’t just go into people’s backyards.”

The idea of how to bridge the gap between the abundance of iNaturalist data logged in urban areas and the rigor expected in scientific research came to Kaiser when she was assigned to watch a lecture given by a Nobel laureate in economics. The lecture topic was synthetic control methods, which originated in economics as a way to create a nonexistent control group that allows for comparisons between real-world groups before and after an event or intervention.

One of the most famous uses of synthetic control methods in economics was in estimating the impact of Germany’s reunification after the fall of the Berlin Wall on the gross domestic product (GDP) of western Germany. Economists created a “synthetic” Germany from economic data to study GDP with and without reunification.

Though synthetic control methods hadn’t been widely used in ecology research, “I thought it could be adopted with iNaturalist data,” Kaiser explains. She was further interested in studying the effects of Hurricane Ida on her home city of Philadelphia, which included significant flooding.

“Even though it didn’t have a huge impact on people per se, the effects of the hurricane were really dramatic. Looking at the water levels, the stream gauges had their highest values ever in the 100 years that they’ve been measuring. My feeling was that would have a pretty big impact on bees, because if you look at bee biodiversity, bees are pretty sensitive to precipitation and water. The ones that nest in the ground are really affected by huge flooding events.”

Declines following a hurricane

To apply synthetic control methods to ecological research, Kaiser and her colleagues drew data from the Global Biodiversity Information Facility, which collects research-grade iNaturalist data—that which includes, among other points, latitude and longitude, collection date and time and correct identification—as a proxy for bee abundance in Philadelphia.

They analyzed for bee population declines and, in addition to synthetic control methods, also performed the more traditional methods of interrupted time series regression, before-after control impact regression and before-after regression.

Kaiser and her colleagues found that synthetic control estimated a 15.5%—20.9% decline in bee observations in the two years following Hurricane Ida. In contrast, the three more common ecological analyses didn’t detect this decline.

“That was an amazing moment, seeing this decline in the data and better understanding how iNaturalist data may be able to help us look at the impact of unusual climate events—things that are happening more and more these days, like huge fires, huge floods, abnormally warm winters,” Kaiser says. “Unless you were already collecting data in a region before, you can’t really see the impact before the event, but synthetic control methods might be able to help us in those situations.”

Kaiser adds that this method also might be useful for looking at the effect of policy interventions. For example, the city of �ֲ��ý is establishing pollinator corridors, and Kaiser sees potential in using this method to draw from iNaturalist data in studying the outcomes of these corridors.

Scientists who reviewed the paper expressed excitement and skepticism about using synthetic control methods in ecological research, Kaiser says: “They asked questions about whether or not the decline I’m seeing is a true thing that’s happening or an artifact of the way data has been collected. iNaturalist is very sensitive to observers—wealthy neighborhoods have higher uploads, areas around research universities have higher uploads—but this statistical method can help control for those things.”

Thanks to the professional and citizen scientists gathering data and sharing it on iNaturalist, Kaiser says she sees potential to apply synthetic control methods to a range of ecological research. For example, “using the bee biodiversity that’s collected on iNaturalist, does that correlate with how well flowers are being pollinated? I think that’s something we’ll be able to study.”

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In research published today, recent PhD graduate Asia Kaiser details how synthetic control methods estimated significant declines in bee observations when traditional analyses didn’t.

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Top photo: Aaron Burden/Unsplash

When climate change threatens sacred sites

Rachel Sauer — Mon, 11 May 2026 22:05:02 +0000

When climate change threatens sacred sites Rachel Sauer Mon, 05/11/2026 - 16:05

Tiffany Plate

CU �ֲ��ý PhD candidate Chilton Tippin assesses how a warming climate is affecting not just humans, but also our archaeological record

In southwestern Colorado, just north of Mesa Verde National Park, sits the scenic—and historic—Canyons of the Ancients National Monument, or CANM. The sprawling monument spans more than 175,000 acres of pinyon-juniper woodlands, salt-desert scrub, big sagebrush plantations and riparian zones.

CANM also happens to be home to critical pieces of Southwest history, including an estimated 30,000 habitation sites, field houses, kivas, shrines, artifact scatters, sacred springs and masonry towers that date as far back as the Paleo-Indian period (10,000–14,500 years ago).

CU �ֲ��ý PhD candidate Chilton Tippin (left) spent months with farmers whose livelihoods depend on the Rio Conchos, a tributary of the Rio Grande in Chihuahua, Mexico. (Photo: Eduardo "Lalo" Talamantes)

But the monument’s location in the high desert makes the landscape, and these historical sites, especially vulnerable to the effects of climate change. In the summer of 2025, Chilton Tippin, a �ֲ��ý anthropology PhD candidate, helped map out exactly how warmer weather and heavy rainstorms could impact these culturally significant structures.

The resulting Climate Change Impact Assessment, which was done with Cooperative Institute for Research in Environmental Sciences (CIRES) colleagues Kira Clark-Wolf and Christy Miller Hesed, was published in January 2026. The project was funded through the Rapid Climate Assessment Program from CU �ֲ��ý’s North Central Climate Adaptation Science Center.

The assessment laid out projections for CANM’s climate future—including many more days with temperatures above 90°F, more days of drought that could lead to increased wildfire risk and more intense and frequent extreme-rainfall events that can cause flooding and erosion.

“This is kind of the initial stepping stone that will hopefully catalyze discussions between the Bureau of Land Management and tribal partners to begin the long planning process for how they're going to adapt the landscape to absorb shocks from climate change,” says Tippin.

Projections and partnerships

To create the projections in the report, Tippin worked from information provided by archaeologists at CANM that pinpointed the exact location of known historical sites. He then used Climate Toolbox to produce climate projections from 20 different models. He compared those projections to literature covering similar projections to come up with general metrics such as how much daily temperatures might increase and how many days the area might go without rain (thus increasing wildfire potential).

At CANM, climate projections show that heat indices will register above 90°F an average of 35 days per year in the 2050s (up from 6 days in the 1990s). (Graphic: climatetoolbox.org)

“We found that most of the stone towers are embedded in pinyon-juniper habitats,” says Tippin. If the climate models and the literature are all saying that the pinyon-juniper forests will be more vulnerable to fire, he says, then they have a better idea of the threats those towers are likely to be facing over the next 50 to 100 years.

“Then CANM can make climate adaptation and forest management decisions so that they can fulfill their mission of protecting not just stone towers, but the kivas, and wiki-ups, and room blocks, too.”

Those decisions would not be made, however, without meaningful input from CANM’s 26 tribal partners whose ancestral presence is reflected in thousands of habitation sites across the landscape.

In cases like these, that knowledge is imperative to take into account. “These are places where their ancestors dwell,” says Tippin. “These heritage sites are part of this living cultural landscape.”

In fact, in the Pueblo worldview, these structures are also deeply spiritual places. “For many Pueblo people, the towers themselves, as well as the materials and rocks within them, are imbued with sentience,” says Tippin. “They're alive, and they themselves have spirit. And the natural course of things is for them to go through processes of decay and reintegration into the ecology.” As a result, a Pueblo person whom Tippin consulted suggested that adapting the habitats in which structures are embedded would be a more culturally appropriate approach than directly shoring up the structures themselves.

Exploring climate-caused conflict

Tippin was tapped to lead the CANM assessment not just for his social science research skills but also for his previous work with indigenous people in the Southwest—much of which he did for his dissertation (completed Spring 2026).

While Tippin’s PhD research is not directly focused on the climate change impacts of historical sites, it still very much explores its impacts on humans, especially in relation to water insecurity. His interest in water interactions stemmed from his childhood in El Paso, Texas, where he spent a lot of time playing in the Rio Grande. Tippin’s experiences with the river and other natural landscapes inspired a lifelong desire to examine, and tell stories, about human interactions with nature.

Chilton Tippin spent several days touring Canyons of the Ancients National Monument’s significant historical sites, including Moose Tower, which was built by Ancestral Puebloans in the late 1200s. In 2020, an extreme rainfall event caused the tower’s west wall (not pictured) to collapse. The storm’s timing and intensity are characteristic of convective rainfall, a type of extreme weather event increasingly linked to climate change in the Southwest. (Photo: Chilton Tippin)

Tippin spent his first few post-college years doing just that, working as a reporter in Wyoming after earning his undergraduate degree in journalism. “For the longest time, I've wanted to tell stories about people and how they interact with the environment, with a specific lens on environmental disputes and conflict,” he says.

So, for his doctoral research, Tippin returned to the Rio Grande and its watershed. The river now sees markedly less flow—thanks in part to a warming climate and diminishing snowpack in the Rocky Mountains—and he wanted to explore the ways those low flows are affecting people who rely on it in one way or another.

To do so Tippin spent a year at three field sites that are all hydrologically connected to the Rio Grande. He first spent several months in Taos, NM, where he teamed up with Puebloans working to protect their traditional uses of water.

Next was El Paso and Juárez, Mexico, where the Rio Grande has become completely militarized. He spent time with the people of the Ysleta Del Sur Pueblo who have a ceremonial relationship with the river, as well as first responders helping deliver water to migrants. “That piece of the dissertation looked at the juxtaposition of this river, which is the bringer of hope and life to the desert and a ceremonial site for the Tigua people,” Tippin says. “How is this same river also the site of widespread, racialized migrant death and violence?”

The final months he spent with farmers along the Rio Conchos in Chihuahua, Mexico, where the river sustains farmers’ agricultural output. In this final site, specifically, Tippin saw how drought and climate change are already causing civil unrest.

In 2020 a rebellion arose among farmers there who were protesting a 1944 treaty that requires Mexico to deliver a certain amount of water from the Rio Conchos to Texas.

“I was in Chihuahua amid that backdrop and came to understand how this megadrought is insinuating itself into people's day-to-day lives,” he says. It was amazing to see how these farmers could mobilize themselves to protect their agricultural water, he says.

Continuing the work

Tippin’s next steps will be to pursue his interest in the human dimensions of climate change through a postdoctoral appointment with the U.S. Geological Survey. He’ll work closely again with the North Central Climate Adaptation Science Center on applied climate-adaptation social science projects.

Part of this postdoctoral work will be to assess how past research projects have been executed in the field; another part is to help ensure agencies like the National Park Service, the Bureau of Land Management, and the Department of Fish and Wildlife have access to the latest climate science when they’re making decisions about land and water management.

In the meantime, he hopes that the climate assessment he performed at CANM can be used to help evaluate similar natural and historic sites.

“It's a niche area within the world of climate change adaptation research,” he says. “But it's just another indication of how climate change is this all-encompassing threat multiplier that affects a lot of things that people find to be valuable.”  

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CU �ֲ��ý PhD candidate Chilton Tippin assesses how a warming climate is affecting not just humans, but also our archaeological record.

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Top image: Bureau of Land Management

Come for the beer, stay for the science

Rachel Sauer — Fri, 08 May 2026 00:07:52 +0000

Come for the beer, stay for the science Rachel Sauer Thu, 05/07/2026 - 18:07

Rachel Sauer

The May 11 Earth on Tap event at Rayback Collective in �ֲ��ý, open to all, invites scientists and non-scientists to gather for discussions of climate research

It started, as good things often do, with CAKE. In this case, that’s the Climate Action Knowledge Exchange, a group formed by �ֲ��ý atmospheric and oceanic sciences (ATOC) graduate students Max Elling, Dora Shlosberg and Josh Gooch. They noticed, the further they progressed in their studies, that there are “a lot of different people working in climate, but not necessarily working together,” explains Shlosberg, a PhD student.

If you go

What: Earth on Tap

When: 5:45-7:30 p.m. Monday, May 11

Where: Rayback Collective, 2775 Valmont Road in �ֲ��ý

Who: All are invited

Learn more

So, they formed an interdisciplinary outreach group, CAKE, to break down silos and build partnerships between scholars, industry professionals and community members. From there, CAKE began collaborating with ATOC’s existing Outreach Committee, a group dedicated to educating the public on Earth science through engaging and interactive learning. Outreach teaches children through their SEEDS program, bringing live demonstrations on Earth-system science to local elementary schools.

Then, last semester, they began discussing what more they could be doing to involve adults in science, particularly those who aren’t professional scientists but are science curious.

Earth on Tap organizers express that there has been a lot of misinformation spread about science, and there is sometimes an element of mystery among the public as to what it is local scientists do. Earth on Tap aims to break down these barriers and connect people of all backgrounds to the science being done in their own backyard.

The key is to make it fun, says ATOC PhD student Maggie Scholer. But how?

The answer: Beer.

Not to make the science go down easier, but as a tool to bring science out of the lab and field research sites and into spaces where all are welcome, where community grows, where learning can happen with a chocolate stout and a shared plate of sliders. So, that’s how Earth on Tap came to be.

An event at which all ages are welcome—though you’ll have to show ID if you want that beer—Earth on Tap features climate scientists discussing their research with a focus on how it applies to and affects the broader community.

The second Earth on Tap will be from 5:45-7:30 p.m. Monday, May 11, at the Rayback Collective in �ֲ��ý. Kyle Manley, an interdisciplinary climate scientist, and Molly Wieringa, a postdoctoral fellow with the National Center for Atmospheric research, will discuss fires and public land recreation as well as sea ice and polar climate engineering.

Telling science stories

Monday’s Earth on Tap topic is especially timely, Josh Gooch says, because he and his ATOC colleagues frequently discuss how “to communicate how abnormal this winter has been and contextualize it to the future. Each week we have a weather discussion that one of our professors leads, and we get these branching discussions of, ‘If we make up the precipitation deficit in the future, what does that mean in terms of more fuel for wildfires?’ So, one of our goals (with Earth on Tap) is to set the context of what current weather events that are occurring on the Front Range may lead to in future seasons. That’s a concern that a lot of people share.”

Max Elling, an ATOC PhD student and researcher in the Oceans and Climate Lab, notes that the �ֲ��ý area is interesting because of its large population of scientists as well as its population of non-scientists, who are nevertheless involved in Earth science, yet there still can be a disconnect between the research that’s happening in this area and what community members know about it.

“With Earth on Tap, we’re learning more about what people are curious about,” Elling says, adding that he and his colleagues are learning to better understand their audiences and tailor their outreach style accordingly.

“We have an inherent language that we use as scientists, certain acronyms, and we’re taught to present at conferences where everyone is aware of this language,” Gooch says. “We need to be more aware of situations where an audience member might not be as familiar because they don’t interface with these things every day.”

Jonah Shaw, a post-doctoral associate at the Cooperative Institute for Research in Environmental Sciences (CIRES) who spoke at the inaugural Earth on Tap in January, adds that all of his communication training in graduate school was in a conference environment, which doesn’t necessarily translate to climate discussions over beers at the Rayback.

“Something that I think is really important when you’re communicating within a scientific field is a story, but it becomes even more important when you’re communicating with the general public,” Shaw says. “It’s meeting people where they are, so for me, instead of talking about what I do on a day-to-day basis, I talked about a satellite mission I worked on, the story of that mission. I was talking about the narrative aspects and connecting with people’s experiences, and I was incredibly excited to see how well attended it was by non-scientists. Everyone is in their own realm and able to connect (with the science) in their own way.”

Scholer says that Earth on Tap organizers learn from event to event how to better involve audience members in the presentation, including trivia questions with prizes and QR codes that people can scan to submit questions if they’re not inclined to raise their hand. Ideally, she adds, people will come to Earth on Tap and have a great time and be more inclined to take climate action when opportunities arise.

“I think, especially in atmospheric science, ideally the outcome of what we do in the field is actionable for policy makers,” says ATOC PhD student Lucas Howard. “I think having the public more informed about not just the science in terms of outcomes, in terms of uncertainty, but the process of what goes into generating the science, can only have good downstream effects.”

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The May 11 Earth on Tap event at Rayback Collective in �ֲ��ý, open to all, invites scientists and non-scientists to gather for discussions of climate research.

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Politicians talk climate change on X

Rachel Sauer — Tue, 05 May 2026 16:54:02 +0000

Politicians talk climate change on X Rachel Sauer Tue, 05/05/2026 - 10:54

Bradley Worrell

Study by CU �ֲ��ý scholar Meaghan Daly looks at how members of Congress framed their arguments for or against taking action on climate change on the popular social media site

For members of Congress, the social media platform X (formerly Twitter) has become one of the most direct ways to communicate with constituents about their thoughts on climate change, allowing them to choose how to address the issue in an unfiltered way.

“X allows politicians to communicate directly and informally with the public, and posts occur much more frequently than polished press releases, so it provides a unique window into how politicians frame climate change in direct engagement with constituents in real time,” explains Meaghan Daly, a climate communications scholar in the �ֲ��ý Department of Environmental Studies whose research focus includes climate communication and media studies.

In a new study, Daly and her co-authors analyze posts on X by members of Congress, finding that while few U.S. lawmakers now reject the science of climate change outright, conservative members tend to frame the issue in ways that discourage or delay meaningful action. Rather than denying the problem, their messages emphasize economic costs, question the feasibility or redirect responsibilities to other countries, Daly says.

Meaghan Daly is a climate communications scholar in the �ֲ��ý Department of Environmental Studies whose research focus includes climate communication and media studies.

Drawing from more than 13,000 climate-related messages in 2021 from members of Congress on X, the study co-authors found a spectrum of political climate communication that ranges from active obstruction to concrete advocacy, with a large “murky middle.”

“This research challenges the idea that climate communication is just pro-climate or anti-climate,” Daly says. “It’s more complex than that, and those nuances matter when we’re trying to understand why action does or doesn’t happen.”

In a recent interview with Colorado Arts and Sciences Magazine, Daly talks about why X offers a uniquely powerful lens for studying political climate communication and how these messaging strategies differ by party. Her remarks have been lightly edited for style and grammar and condensed for space.

Question:How did this paper come together?

Daly: I’m a member of the Media and Climate Change Observatory, headed by Max Boykoff in the Department of Environmental Studies. We’ve been doing global monitoring of media coverage of climate change for about 15 years now across newsprint, radio and television.

One of my co-authors, Lucy McAllister (assistant professor at Denison University and a research associate with the Department of Environmental Studies at CU �ֲ��ý), is also part of that group. We’ve worked on several projects over the years, including media coverage in legacy news outlets across five countries over time. Our other co-author, Siddharth Vedula (associate professor at Miami University), has also been a long-time collaborator. All three of us received our doctorates from CU �ֲ��ý, and the team brought together a strong mix of qualitative and quantitative research backgrounds.

For this paper, we noted in our 2021 study on newspaper coverage that, while climate denial used to be common, more recently fewer people deny climate change outright. Instead, there’s been a shift toward questioning the feasibility of taking action.

�ֲ��ý six years ago, a group of scholars published a paper about what they called ‘discourses of delay.’ That paper was preliminary, and in our 2021 study we noted the need to follow up and examine these discourses in greater detail—particularly how they interface with the public in the political sphere. There hadn’t been a comprehensive study of how U.S. politicians communicate about climate change on social media, so we wanted to see how these discourses of delay manifest in political communication.

But we then expanded that framework because we didn't want to just look at how is climate action being delayed, but also how is climate action being advanced, by U.S. politicians. We wanted to have this entire spectrum, looking from delay to action and everything in between, and how politicians are approaching this issue and communicating with the public about it.

Question:Why did you choose to focus on the January to December 2021 timeframe for members of Congress posting on X about climate change?

Daly: We chose 2021 because a lot was happening. The Biden Administration had recently rejoined the Paris Climate Agreement, and multiple major pieces of legislation—what became the Infrastructure Investment and Jobs Act and the Inflation Reduction Act, as well as Build Back Better—were being actively discussed. That gave us a rich dataset and a good microcosm for understanding how climate conversations were being framed and the range of communication strategies being used.

Question:You collected more than 13,000 posts from politicians on X that were related to climate change but then focused on a much smaller subset. How confident are you that the smaller sample represents the broader dataset?

Daly: We started with about 600,000 posts and used an initial screening with established search terms from prior research to ensure they were actually about climate change, which produced a sample of about 13,000 posts. From there, we applied a randomized sampling method stratified by month, since discussion topics ebb and flow over time.

We also conducted six rounds of pilot testing to refine the codebook. Throughout, we ran randomized spot checks and maintained over 80% inter-coder agreement. The final randomized sample had 1,075 posts. Across the pilot and final analysis, we coded a total of 2,844 posts, or 21% of the total sample, which for a qualitative study is quite comprehensive and gives a detailed understanding of communication strategies.

Question:It sounds like the discussion about climate change has moved beyond whether the science is accurate to whether it is feasible to take action to address the issue?

Daly: Yes, absolutely. We saw very few posts questioning the existence of climate change or the science itself. Instead, many posts emphasized downsides—potential economic damage, harm to the fossil fuel industry or job losses. Others redirected responsibility, asking why the U.S. should act if other countries aren’t doing so. Why should we have to be the ones who are taking the lead or paying to implement some of these policies when the rest of the world isn't doing the same?

We also saw a lot of posts pushing non-transformative solutions—unproven technologies, ‘clean coal’ or these fossil fuel–based approaches that are ostensibly less polluting but, in practice, typically aren’t.

Also, we saw postings that we should only rely on things like incentives rather than government regulation or policy mandates that we act on climate change. Basically, arguing we should only have voluntary approaches to addressing climate change, rather than requiring action. So, solutions that aren’t at the scale needed to address climate change.

Question: If a conservative politician talks about job losses or other potential downsides of addressing climate change on X, how do you differentiate between them raising valid questions versus engaging in what could be considered delaying tactics?

Daly: We do know that there are always trade-offs in climate policy. We’re not trying to say that we don’t need to acknowledge those trade-offs.

For example, in making the argument that, as we shift away from fossil fuels and toward more renewable energy technologies, we need to make sure that those people who were working in those industries and relied on it for their livelihoods are not left behind. That’s something that I think is very important to acknowledge and that can get lost in this conversation.

We need to make sure that this is a fair transition, and that those people are connected with jobs and new opportunities in these emerging sectors that are going to create new types of jobs. That comes along with other policy components like retraining, and that’s not treated as a bad thing in our codebook.

"This study is a starting point for understanding how politicians communicate about climate change and how they might improve that communication to advance action," says Meaghan Daly. "One key takeaway is connecting climate discussion to specific actions so people don’t feel the problem is overwhelming and unsolvable." (Photo: iStock)

The way we addressed this is: If people are talking about these downsides, but they are not acknowledging the gravity of climate change at the same time—because it is this massive problem that is going to affect us all in really deep ways that are integral to how we live—that’s when we felt it qualified as delaying rather than simply acknowledging there are trade-offs in all climate policies.

Question:For those members of Congress who have been proponents of taking action on climate change, what kinds of messages did they post?

Daly: Posts promoting climate action emphasized benefits and co-benefits—health, ecosystems and quality of life. Many argued that because the U.S. has historically contributed the most to the problem, it should lead globally, especially as the country rejoined the Paris Climate Accord. There were also many posts highlighting legislation being passed or developed, budget allocations and building systems and structures for action. We describe this as ‘grounded optimism’—linking climate discussion to concrete legislative or on-the-ground action, rather than vague future hope.

Question:Do you know whether some arguments were more effective than others, either on the pro-action or delay-action side?

Daly: I think that’s a great question. This study didn’t address effectiveness in terms of public response, but I think that’s an important next step for future research.

Question:Did you find differences among members of Congress by age, race or ethnicity when it came to posting on X about climate change?

Daly: Yes. Politicians of color were more likely to post about climate change, likely because they represent constituencies on the front lines of climate impacts. Older politicians were also more likely to post about climate action, possibly because their longer tenure gives them more leeway to address controversial issues.

Question:You say in the paper that climate obstructionism can be intentional or unintentional. What do you mean by that?

Daly: One key contribution of the study is identifying what we call the ‘murky middle.’ Some communication strategies can support action or delay depending on context. For example, ‘all talk, little action’ was previously categorized as a delay (tactic), but talking about climate change does raise issue salience. However, simply talking isn’t enough—if it’s not paired with concrete strategies, people may feel overwhelmed and disengage. Posts in this category acknowledged climate change but weren’t attached to pathways for action, which can inadvertently contribute to delay.

Question:Are you planning follow-up work on this topic?

Daly: Yes. Our next step is to apply this typology over a longer timeframe. We’re exploring mixed-methods approaches, including using large language models to apply our codebook at scale, because manual coding is extremely time-intensive.

This study is a starting point for understanding how politicians communicate about climate change and how they might improve that communication to advance action. One key takeaway is connecting climate discussion to specific actions so people don’t feel the problem is overwhelming and unsolvable.

The research also challenges the idea that climate communication is simply pro- or anti-climate. It’s more of a spectrum, which opens up important avenues for future research.

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Study by CU �ֲ��ý scholar Meaghan Daly looks at how members of Congress framed their arguments for or against taking action on climate change on the popular social media site.

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Documentary shares secrets of the bees

Rachel Sauer — Fri, 03 Apr 2026 14:21:04 +0000

Documentary shares secrets of the bees Rachel Sauer Fri, 04/03/2026 - 08:21

Rachel Sauer

CU �ֲ��ý researcher Samuel Ramsey served as science advisor and a producer, alongside executive producer James Cameron, for Secrets of the Bees, premiering this week on National Geographic, Disney+ and Hulu

Would you like to hear a secret about bees?

Not many people know this, but bees in Southeast Asia have figured out that water buffalo dung isn’t the only pungent substance that will keep hornets away.

See, Vespa mandarinia—more sensationally known as the murder hornet—can wreak havoc on a bee colony. One or two dozen hornets can wipe out an entire colony, although bees have developed some pretty awesome defenses. One of these involves vibrating their flight muscles to create a convection oven effect that essentially cooks invading hornets.

Samuel Ramsey, a �ֲ��ý assistant professor of ecology and evolutionary biology, served as science advisor and producer, alongside executive producer James Cameron, on the documentary Secrets of the Bees. (Photo: Shin Arunrugstichai)

However, sometimes a hornet can escape bees’ defenses and flee the hive—but not before leaving a figure-eight pattern of pheromones outside the hive that acts as a beacon to future hornet invasions. Bees deduced that they’d need something even more pungent to spread at the hive entrance to mask the hornet pheromones, “and for a long time we thought they were just relying on water buffalo dung for that purpose,” explains Samuel Ramsey, a �ֲ��ý assistant professor of ecology and evolutionary biology.

But bees are smart. They figured out they could chew the leaves of an extremely pungent plant to spread at the hive entrance, “which was something we’d never seen before,” Ramsey says.

He and his colleagues discovered this behavior in pursuit of Secrets of the Bees, the fifth installment of the Emmy Award-winning “Secrets of…” series premiering this week on National Geographic, Disney+ and Hulu.

Ramsey, a National Geographic Explorer, served not only as science advisor and featured expert, but as a producer alongside executive producer James Cameron.

Yes, that James Cameron.

“It’s always a pleasure to say I produced a documentary with James Cameron,” Ramsey says with a laugh. “It’s opened up a lot of opportunities to talk with people about bees and together making sure that there’s unity in concept—so we’re not talking in terms of ‘right’ bees and ‘wrong’ bees, but we’re talking about what we can do to support all bees’ survival.”

Communicating science (and bees)

This all came about, in part, because “bees really, really need our help,” Ramsey says, a fact he quickly realized as a lifelong, self-described “bug nerd” observing how human-caused changes to the natural world are affecting bee populations.

During his undergraduate and graduate studies, Ramsey focused on diseases and parasites affecting bees, particularly the Varroa mite, and began raising bees so that he could study them. When he came to CU �ֲ��ý, that move included installing a research and observation hive in his lab in the Jennie Smoly Caruthers Biotechnology Building.

Because his research interests also include symbiotic relationships, it’s perhaps no surprise that Ramsey the scientist is also Ramsey the science communicator: passionate about describing the beauty, wonder, fragility and resiliency of the natural world to broad and interested—although often non-scientific—audiences. He has been at the vanguard of using social media to tell the dynamic stories of science.

Thanks in part to this outreach, documentarians and filmmakers began requesting his expertise and consultation. He worked on the documentary My Garden of a Thousand Bees and has discussed insects on NPR, CBS and many other outlets, in addition to becoming a National Geographic Explorer. Still, he says, it’s a little surreal to get that call proposing a collaboration with the director of Titanic and Avatar.

“(Cameron) has 300 hives at his farm in New Zealand, so this really has been a labor of love for him,” Ramsey says.

Making a difference for bees

The framework of Secrets of the Bees is to show a hive of honeybees preparing for winter, but that simple concept took Ramsey and his collaborators around the world, exploring bee colonies as the dynamic cities they are and bees not as mindless automatons, but as intelligent, adaptive creatures that form complex societies.

The filmmakers used groundbreaking technologies, including cameras similar to those used in endoscopes, to peer inside hives for never-before-seen views of bees living, working and playing together. Yes, bees play, Ramsey says, and it’s a wonderful thing to see.

The cutting-edge filmmaking technology allows viewers to see close-up, time-lapse scenes of larva growing into adult bees, as well as the funerary process of pushing dead bees from the hive. “The advent of universal childcare is what allowed this to be one of the most successful species on the planet,” Ramsey says, “which you really see up-close in the film.”

He adds that it was important to him that the documentary not sugarcoat the peril in which Earth’s more than 20,000 bee species currently exist, including calamitous population declines associated with climate change, monoculture crops, parasites, chemical use and habitat loss, among other causes.

“But the film also emphasizes hope, because there are things every one of us can do to support bees,” Ramsey says. “Something as simple as planting a window box with flowers can make a big difference to a lot of bees.”

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CU �ֲ��ý researcher Samuel Ramsey served as science advisor and a producer, alongside executive producer James Cameron, for Secrets of the Bees, premiering this week on National Geographic, Disney+ and Hulu.

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Project harnesses next-generation satellites to preserve Arctic sea ice

Rachel Sauer — Tue, 17 Mar 2026 22:11:24 +0000

Project harnesses next-generation satellites to preserve Arctic sea ice Rachel Sauer Tue, 03/17/2026 - 16:11

CU �ֲ��ý researcher Ivy Tan leads a project recently funded by Ocean Visions that aims to assess whether mixed-phase cloud thinning is a viable method for cooling the Arctic

Ivy Tan, a �ֲ��ý assistant professor of physics, recently was awarded funding from Ocean Visions for a project she leads that is assessing whether mixed-phase cloud thinning is a viable method for cooling the Arctic and restoring sea ice.

Tan’s project is one of six funded by Ocean Visions, a nonprofit ocean conservation organization pursuing solutions to counter and reverse climate impacts on ocean health. The selected projects are being funded through Ocean Visions’ Arctic Sea Ice Restoration Research Fund, which was created to identify, prioritize and support research on cutting-edge ideas to slow the loss of Arctic sea ice.

“Arctic summer sea ice is a critical foundation of the global ocean and climate system, and its rapid loss is creating a series of severe risks to nature and people across the planet,” says Brad Ack, Ocean Visions CEO. “These research projects, and others to come, are intended to help answer the glaring question: Is there anything else we can do to forestall these potentially irreversible outcomes?”

“This support from Ocean Visions will allow us to better understand the radiative influence of Arctic clouds on the rapidly warming Arctic by spectrally fingerprinting the far infrared radiative signature of clouds using state-of-the-art technology,” Tan says.

Tan and her research colleagues—Sebastian Schmidt, a CU �ֲ��ý professor of atmospheric and oceanic sciences, Michael Diamond at Florida State University and Colten Peterson with the NASA Goddard Space Flight Center—are developing a new, satellite-based Arctic cloud observation product using recently launched satellites with unprecedented routine measurements of far-infrared radiation (NASA’s PREFIRE CubeSats), as well as collocated radar, LiDAR and imager instruments.

“We will compare the satellite observations to those made with ESA/JAXA’s recently launched EarthCARE satellite and an aircraft (as part of NASA’s ARCSIX campaign),” Tan and her colleagues explain. “These comparisons will be used to produce and validate an algorithm that provides information on cloud properties and their radiative effects on the Arctic surface on a broad spatial scale. Our framework will uniquely take into account the influence of the vertical thermal stratification of the Arctic atmosphere helping us to determine where and when mixed-phase cloud seeding would, or would not, have potential as a climate intervention strategy.”

Among their aims is to help make mixed-phase cloud thinning a more viable method for cooling the Arctic and restoring sea ice. For this to happen, however, “there would need to be enough of the right type of cloud present to be thinned by seeding (clouds containing supercooled liquid water), at the right time (polar night), to produce the desired climate forcing (cooling). Unfortunately, accurately measuring these clouds, especially at night, is very challenging with current satellite products,” the researchers explain.

Ocean Visions selected the six projects through a competitive process, including review by an independent international expert panel. The research to be conducted will provide the foundation for future work, if warranted, to further advance knowledge and address ecological, social and ethical dimensions, as well as develop guidance on safeguards or stage gates for future research, according to Ocean Visions.

“The research supported through the Arctic Sea Ice Restoration Research Fund prioritizes scientific merit, interdisciplinary approaches, and careful risk assessment through a rigorous review,” says Dr. Ginny Selz, Ocean Visions senior program director. “We are excited to watch this research progress and see how it expands our understanding of potential approaches to protect and restore Arctic sea ice.”

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CU �ֲ��ý researcher Ivy Tan leads a project recently funded by Ocean Visions that aims to assess whether mixed-phase cloud thinning is a viable method for cooling the Arctic.

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