Category: The Conversation – USA

Source: The Conversation – USA – By Charlie Hunt, Associate Professor of Political Science, Boise State University

On Feb. 7, 2026, Chasity Verret Martinez won a special election to fill a vacant seat in the Louisiana House. That’s an outcome that might not mean very much to people outside of the state or even outside her Baton Rouge-area district.

But Martinez is a Democrat who took 62% of the vote in a district that had given Donald Trump a 13-percentage-point victory in the 2024 presidential race. And her win came a week after Democrats seized a Texas Senate district that had supported Trump even more strongly – a result that immediately triggered concern in Republican circles.

Because fewer people turn out for special elections, they’re considered an early predictor of partisan enthusiasm heading into regularly scheduled elections. And with the 2026 midterm elections less than nine months away, analysts are already scrambling for indications of the likely outcome.

As a political scientist who studies congressional elections, I’m interested in the question of whether special elections can really tell us which way the political winds are currently blowing.

Democrats, of course, are hoping for a “blue wave” like they rode in 2018, when they picked up 40 House seats and won a majority in that chamber, while Republicans want to hang on to the very slim margins they have in both the House and Senate.

In the 2026 election cycle, as in previous ones, prognosticators and political professionals are looking to the outcomes of these intermittent races at various levels of government as a gauge of how voters are feeling about the two parties. And the results from the first 15 months of the second Trump administration appear to spell very bad news for the Republicans.

Setting a baseline

Since Election Day 2024, 88 special elections featuring candidates from both major parties have taken place for institutions including state legislatures and the U.S. House.

When analyzing the results of these races, it’s important to have figures to compare them to. After all, a Democrat just barely squeaking by in a state legislative race may not look very impressive on its face – but if that race took place in the rural heart of a red state, it could raise hackles among Republicans.

Most political analysts agree that the best available comparison point for special elections are the results for the most recent presidential election in that same district. There are a few reasons for this.

The nationalization of party politics means there are few members of Congress representing states or districts that voted for the other party for president. So the best comparison is to the only truly national election in the U.S.

Second, using presidential results creates the same baseline for all races. By comparing special election results to the prior election environment, all the special election results get compared to the same standard.

Finally, and perhaps most importantly, recent midterm elections have typically served as a referendum on the party in power, particularly the president. In trying to measure how voters are reacting to Trump’s second term, it makes sense to measure their behavior against the last time Trump was on the ballot.

Are special elections predictive?

With this baseline in mind, it’s easy to compare the results of special elections in particular districts to the results of the last presidential election in that same district.

In the 2022 cycle, for example, Democrats running in special elections underperformed President Joe Biden’s 2020 results in their districts by about 4 percentage points on average, which translated into a 3-percentage-point loss nationwide in U.S. House races in the November 2022 midterms and the loss of their majority in the chamber.

Conversely, in 2018 – like this year, a midterm following a Trump election – Democrats bested Republicans by 8 percentage points in November, after overperforming Hillary Clinton’s 2016 margins in special elections throughout the previous two years by 9 percentage points on average.

The 2024 cycle is a clear exception to this pattern of regular elections closely following special election results: Prior to the presidential election, Democrats outperformed in special elections by an average of 4 percentage points but ended up losing nationally by 3 percentage points in November.

Like special elections, midterm contests tend to turn out fewer but more engaged voters than presidential years. Therefore, it may be that special elections are more predictive of midterm results than presidential cycles. At any rate, if previous midterm outcomes are any guide, the numbers being posted by Democrats in special elections so far in the 2026 cycle are impossible to ignore.

On average, they’re running ahead of Harris’s 2024 margins by a whopping 13 percentage points. That’s better than they did in 2018, when they ultimately picked up 40 seats in the House and seven governorships across the country.

What’s different about specials?

Democrats, however, may not want to pop the champagne corks just yet. Many roadblocks remain in their quest to take back control of Congress. For one thing, the U.S. Senate map remains a difficult one for Democrats. Even if they end up creating a 2018-like election environment with an unpopular president, many Senate contests are taking place in solidly red states.

It’s also always worth bearing in mind that there’s no telling how the events of the next nine months might reshape public opinion.

And special elections, while useful metrics, are far from perfect barometers of public opinion. They take place at different times, and could be just as reflective of hyperlocal factors, such as flawed candidates, as they are of nationalized partisan conditions.

Special elections tend to have far lower turnout than regular midterm or presidential contests. It’s also difficult to tell whether overperformance is due to highly motivated partisans or persuasion of independents and voters from the other party.

Using all the tools available

Still, special elections do have key advantages over traditional polling. Although polls do their best to approximate voters’ political attitudes, elections reveal these attitudes through voters’ actual, observed behavior – exactly the type of behavior that analysts are trying to predict in November.

Generally, this is preferable to asking a hypothetical in opinion polls, which are getting more difficult than ever to do well.

In the end, special elections are just one piece of the prediction puzzle. But the other puzzle pieces are also spelling out potential bad news for the GOP.

The generic ballot, a standard polling question that asks voters’ intent to vote for one party or the other in November without naming specific candidates, has the GOP about 6 percentage points behind the Democrats. Trump’s approval rating, meanwhile, continues to hover below 40%.

There’s no telling for sure whether these indicators will turn out to be truly predictive until November. But all of them should be sounding alarm bells for Republicans.

Charlie Hunt does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Do special election results spell doom for Republicans in 2026? – https://theconversation.com/do-special-election-results-spell-doom-for-republicans-in-2026-274912

Source: The Conversation – USA (3) – By Jonathan Levy, Professor and Chair, Department of Environmental Health, Boston University

The Trump administration took a major step in its efforts to unravel America’s climate policies on Feb. 12, 2026, when it moved to rescind the 2009 endangerment finding – a formal determination that six greenhouse gases that drive climate change, including carbon dioxide and methane from burning fossil fuels, endanger public health and welfare.

But the administration’s arguments in dismissing the health risks of climate change are not only factually wrong, they’re deeply dangerous to Americans’ health and safety.

As physicians, epidemiologists and environmental health scientists, we’ve seen growing evidence of the connections between climate change and harm to people’s health. Here’s a look at the health risks everyone face from climate change.

Extreme heat

Greenhouse gases from vehicles, power plants and other sources accumulate in the atmosphere, trapping heat and holding it close to Earth’s surface like a blanket. Too much of it causes global temperatures to rise, leaving more people exposed to dangerous heat more often.

Most people who get minor heat illnesses will recover, but more extreme exposure, especially without enough hydration and a way to cool off, can be fatal. People who work outside, are elderly or have underlying illnesses such as heart, lung or kidney diseases are often at the greatest risk.

Heat deaths have been rising globally, up 23% from the 1990s to the 2010s, when the average year saw more than half a million heat-related deaths. Here in the U.S., the 2021 Pacific Northwest heat dome killed hundreds of people.

Climate scientists predict that with advancing climate change, many areas of the world, including U.S. cities such as Miami, Houston, Phoenix and Las Vegas, will confront many more days each year hot enough to threaten human survival.

Extreme weather

Warmer air holds more moisture, so climate change brings increasing rainfall and storm intensity and worsening flooding, as many U.S. communities have experienced in recent years. Warmer ocean water also fuels more powerful hurricanes.

Increased flooding carries health risks, including drownings, injuries and water contamination from human pathogens and toxic chemicals. People cleaning out flooded homes also face risks from mold exposure, injuries and mental distress.

Climate change also worsens droughts, disrupting food supplies and causing respiratory illness from dust. Rising temperatures and aridity dry out forests and grasslands, making them a setup for wildfires.

Air pollution

Wildfires, along with other climate effects, are worsening air quality around the country.

Wildfire smoke is a toxic soup of microscopic particles (known as fine particulate matter, or PM2.5) that can penetrate deep in the lungs and hazardous compounds such as lead, formaldehyde and dioxins generated when homes, cars and other materials burn at high temperatures. Smoke plumes can travel thousands of miles downwind and trigger heart attacks and elevate lung cancer risks, among other harms.

Meanwhile, warmer conditions favor the formation of ground-level ozone, a heart and lung irritant. Burning of fossil fuels also generates dangerous air pollutants that cause a long list of health problems, including heart attacks, strokes, asthma flare-ups and lung cancer.

Infectious diseases

Because they are cold-blooded organisms, insects are directly influenced by temperature. So with rising temperatures, mosquito biting rates rise as well. Warming also accelerates the development of disease agents that mosquitoes transmit.

Mosquito-borne dengue fever has turned up in Florida, Texas, Hawaii, Arizona and California. New York state just saw its first locally acquired case of chikungunya virus, also transmitted by mosquitoes.

And it’s not just insect-borne infections. Warmer temperatures increase diarrhea and foodborne illness from Vibrio cholerae and other bacteria and heavy rainfall increases sewage-contaminated stormwater overflows into lakes and streams. At the other water extreme, drought in the desert Southwest increases the risk of coccidioidomycosis, a fungal infection known as valley fever.

Other impacts

Climate change threatens health in numerous other ways. Longer pollen seasons increase allergen exposures. Lower crop yields reduce access to nutritious foods.

Mental health also suffers, with anxiety, depression and post-traumatic stress following disasters, and increased rates of violent crime and suicide tied to high-temperature days.

Young children, older adults, pregnant women and people with preexisting medical conditions are among the highest-risk groups. Lower-income people also face greater risk because of higher rates of chronic disease, higher exposures to climate hazards and fewer resources for protection, medical care and recovery from disasters.

Policy-based evidence-making

The evidence linking climate change with health has grown considerably since 2009. Today, it is incontrovertible.

Studies show that heat, air pollution, disease spread and food insecurity linked to climate change are worsening and costing millions of lives around the world each year. This evidence also aligns with Americans’ lived experiences. Anybody who has fallen ill during a heat wave, struggled while breathing wildfire smoke or been injured cleaning up from a hurricane knows that climate change can threaten human health.

Yet the Trump administration is willfully ignoring this evidence in proclaiming that climate change does not endanger health.

Its move to rescind the 2009 endangerment finding, which underpins many climate regulations, fits with a broader set of policy measures, including cutting support for renewable energy and subsidizing fossil fuel industries that endanger public health. In addition to rescinding the endangerment finding, the Trump administration also moved to roll back emissions limits on vehicles – the leading source of U.S. carbon emissions and a major contributor to air pollutants such as PM2.5 and ozone.

It’s not just about endangerment

The evidence is clear: Climate change endangers human health. But there’s a flip side to the story.

When governments work to reduce the causes of climate change, they help tackle some of the world’s biggest health challenges. Cleaner vehicles and cleaner electricity mean cleaner air – and less heart and lung disease. More walking and cycling on safe sidewalks and bike paths mean more physical activity and lower chronic disease risks. The list goes on. By confronting climate change, we promote good health.

To really make America healthy, in our view, the nation should acknowledge the facts behind the endangerment finding and double down on our transition from fossil fuels to a healthy, clean energy future.

This article includes material from a story originally published Nov. 12, 2025.

Jonathan Levy receives funding from the National Institutes of Health, the Federal Aviation Administration, the City of Boston, the Masschusetts Office of the Attorney General, and the Mosaic Foundation.

Howard Frumkin has no financial conflicts of interest to report. He is a member of advisory boards (or equivalent committees) for the Planetary Health Alliance; the Harvard Center for Climate, Health, and the Global Environment; the Medical Society Consortium on Climate Change and Health; the Global Consortium on Climate and Health Education; the Yale Center on Climate Change and Health; and EcoAmerica’s Climate for Health program, and chairs the National Academy of Medicine Committee on the Roadmap for Transformative Action to Achieve Health for All at Net-Zero Emissions—all voluntary unpaid positions.

Jonathan Patz receives funding from the National Institutes of Health. He is affiliated with the Medical Society Consortium for Climate and Health, and its affiliate Healthy Climate Wisconsin.

Vijay Limaye is affiliated with the Natural Resources Defense Council.

– ref. Trump’s EPA decides climate change doesn’t endanger public health – the evidence says otherwise – https://theconversation.com/trumps-epa-decides-climate-change-doesnt-endanger-public-health-the-evidence-says-otherwise-275619

Source: The Conversation – USA (3) – By Christopher Lieu, Professor of Medical Oncology, University of Colorado Anschutz Medical Campus

An increasing number of people are dying of colorectal cancer at a young age, including those as young as 20. Actor James Van Der Beek, who was diagnosed with colorectal cancer in 2023, died at age 48 on Feb. 11, 2026, bringing the disease back into the limelight.

The Conversation U.S. asked gastrointestinal oncologist Christopher Lieu and cancer researcher Andrea Dwyer to explain what’s known about early-onset colon cancer and what young people can do to protect themselves.

Why are more young people getting colorectal cancer?

Researchers have identified a number of factors associated with increasing numbers of young people developing colorectal cancer, but there is no one clear answer that explains this trend.

Lifestyle factors like ultra-processed foods and alcohol, as well as lack of exercise, have been linked to early-onset colorectal cancer. However, these are correlations that aren’t proven to be the cause of colorectal cancer in young adults.

Many researchers are focusing on the gut microbiome, which is an ecosystem of microorganisms in your gut that helps your body digest food and carry out other important functions. When the microbes in the gut are out of balance – a condition called dysbiosis – this causes a disruption that allows for inflammation and negative health effects, including increased cancer risk.

What increases your risk of developing colorectal cancer?

Beyond genetics, several lifestyle factors can increase your risk of developing colorectal cancer.

For example, someone’s diet plays a role in cancer risk. Eating a lot of red meat and processed foods and not enough dietary fiber can increase your risk of colorectal cancer. Alcohol also causes cancer – even having less than one drink a day can increase your cancer risk.

Smoking, obesity and lack of exercise are other factors that increase cancer risk.

What’s the survival rate for young people with colon cancer?

There is a lot of debate among researchers on whether there are differences in survival rates between those with early-onset colorectal cancer survival and those who develop the disease after age 50.

Finding cancer at an early stage can lead to five-year survival rates as high as 80% to 90%. When cancer is detected at an advanced stage where it has spread to other parts of the body, survival rates are closer to 10% to 15%.

One study found that young patients with metastatic colon cancer had a slightly lower survival rate compared with those age 50 or older.

What are early symptoms of colorectal cancer?

The most common signs and symptoms for early-onset colorectal cancer are blood in the stool, abdominal pain and a change in bowel habits, or any combination of these conditions. Unexplained anemia, or low red blood cell levels, is another potential symptom. These are warning signs that people should not ignore.

Having these symptoms does not necessarily mean you have colorectal cancer, but they are worth discussing with a physician. In some cases, your doctor may request a colonoscopy for further evaluation.

How does colon cancer screening work?

The first step is to have a conversation with your health care team about which test is right for you. Understanding what your risk category is helps guide screening, prevention and lifestyle changes to reduce your likelihood of colorectal cancer.

People with an average risk for colorectal cancer typically have no personal or significant family history of colorectal cancer, hereditary cancer, precancerous polyps or inflammatory bowel disease. They have several options for screening, including stool tests that check for blood and abnormal cells, as well as imaging scans to visualize the colon and rectum. Screening is recommended to begin at age 45 and should continue at regular intervals until age 75.

People with a high risk of colon cancer typically have a personal or family history of colorectal cancer, hereditary cancer or inflammatory bowel disease. They may also have several lifestyle risk factors. Colonoscopy is the only recommended screening test for those with high risk, and earlier and more frequent screening may be necessary.

How can you reduce your risk of colon cancer?

Communication and action are key. Talk to your health care team about your personal risk based on your age, family history and any signs and symptoms to ensure you’re matched with the screening exam and test best for you.

Take charge of your health. There are lifestyle factors you can control to reduce your personal risk of colorectal cancer. These include regular physical activity; a diet high in fruit, vegetables and fiber, and low in processed meats; and maintaining a healthy weight. Moderating or eliminating alcohol and tobacco use can also reduce your colorectal cancer risk.

Share information with loved ones and your health care team. Knowing your personal and family history of polyps or colorectal cancer and communicating it with your doctor can help ensure you get the right test at the right time. Sharing your personal history could save the lives of your children, siblings and parents.

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

– ref. Colorectal cancer is increasing among young people, James Van Der Beek’s death reminds – cancer experts explain ways to decrease your risk – https://theconversation.com/colorectal-cancer-is-increasing-among-young-people-james-van-der-beeks-death-reminds-cancer-experts-explain-ways-to-decrease-your-risk-275886

Source: The Conversation – USA – By Jamey Jacob, Regents Professor of Aerospace Engineering and Executive Director, Oklahoma Aerospace Institute for Research and Education, Oklahoma State University

When the Federal Aviation Administration closed the airport in El Paso, Texas, and the airspace around it on Feb. 10, 2026, the cause was, ironically, the nearby use of a technology that could be key to keeping airports and airspace open and safe.

According to news reports, Customs and Border Protection officials used a Department of Defense anti-drone laser weapon to target what they identified as a drone crossing the border from Mexico. The FAA closed the El Paso airport and airspace out of concern that the weapon inadvertently posed a threat to air traffic in the area.

The targeted drone turned out to be a party balloon, though U.S. officials claim that drug cartels based in Mexico have flown drones at the U.S.-Mexico border. The episode highlights the need for counter-drone technologies, the state-of-the-art systems used by the U.S. military, and the challenges to safely and effectively countering drones, which are also known as uncrewed aircraft systems.

I am an aerospace engineer and director of the Counter-UAS Center of Excellence at Oklahoma State University, where we develop and evaluate technologies to detect, identify and counter drone threats. The military laser weapon CBP that personnel used near El Paso is an example of one of three categories of counter-drone technologies: directed energy weapons. The other two are radio frequency jamming and kinetic, or physical, weapons like missiles and nets.

The emerging threat

Starting in 2015, the ISIS terrorist group modified commercial off-the-shelf drones to drop grenades and mortars on U.S. troops in Iraq and Syria, who had little way to combat the threat. This started the trend of modifying consumer drones for military purposes that continues to this day on the Russian-Ukrainian front lines.

While military bases ostensibly have some protective capabilities, critical U.S. infrastructure such as airports and power plants have few methods to track, let alone defend against, drones. For example, in 2018, traffic at London Gatwick International Airport in the U.K. was shut down for three days because of an unidentified drone in the airport’s airspace. Hundreds of flights were canceled, affecting over 100,000 passengers.

Sites such as civilian and military airports, power plants and stadiums are vulnerable to drone flights, both from malicious and negligent operators. Drone flight over open stadiums such as those hosting upcoming FIFA World Cup soccer matches are banned by the FAA. But the ban wouldn’t prevent an errant civilian drone or a drone used in a terrorist attack from entering a stadium and potentially causing serious harm to spectators.

On June 1, 2025, Ukrainian forces deployed more than 100 “kamikaze” drones deep in Russian territory in an attack labeled Operation Spiderweb that damaged a significant portion of Russia’s bomber fleet. There is little stopping something like this from happening in the U.S.

To address this threat, companies are evaluating numerous ways to track, identify and, most importantly, defeat drones and protect critical U.S. infrastructure. At present, however, there is no one-size-fits-all solution.

Counter-drone technologies

Radio frequency waves that both track and jam drones have become widely used in the Russia-Ukraine war. Like all remote control devices, drones use radio frequencies to control flight and monitor video coming from the drone camera. Detectors can track these radio frequency signals to determine a drone’s location.

Devices that emit radio frequency signals can be used to block, or jam, communications between drones and their operators or send false, or spoofed, signals. Jamming or spoofing a drone typically causes it to enter into a “return to home” mode and leave the defended area. Radio frequency systems are helpful in situations where a low-impact response is required, because they prevent drones from completing their intended mission without causing physical damage to them.

However, this doesn’t necessarily work if a drone is operating in a “run silent” mode by not transmitting information back to a remote operator. Similarly, jamming GPS can cause a drone to lose its ability to navigate using the satellite system, but this also blocks GPS signals for other users. Drones can also navigate without GPS, with less accurate techniques such as following terrain with cameras or the dead reckoning approach commonly used by pilots.

Directed energy systems, on the other hand, use high-energy lasers or microwave beams to disable drones. These systems work by directing a concentrated beam of energy toward an incoming drone. A laser or microwave can heat components rapidly until the drone becomes inoperative. A laser can also disable a drone’s camera, disabling its surveillance capability. Additionally, because these systems use energy beams, they can engage multiple drones at once.

However, fast-moving drones may be difficult for the weapons to target, and the cost of such systems makes them prohibitively expensive for widespread use.

Kinetic systems involve physically intercepting drones to neutralize them. This category includes everything from net-carrying interceptor drones to traditional projectile weapons, such as firearms and missiles. Kinetic systems physically disable or capture drones, making them particularly useful in scenarios where it is necessary to quickly remove drones from sensitive areas or when the drone presents an immediate threat.

However, because a damaged aircraft can crash in unpredictable locations, these systems may be more effective in battlefields where falling debris is less likely to cause unwanted damage on the ground.

Swiss cheese safety

Together, these three types of counter-drone technologies – radio frequency, directed energy and kinetic – provide a comprehensive tool kit for addressing the diverse threats posed by unauthorized drones. However, there is no single ideal solution to counter these threats.

To maximize safety, the Swiss cheese model is often the best approach. In this analogy, each defensive strategy is a slice of the familiar holey cheese. While some threats may pass through a hole in one layer, the next layer can capture what passes through. This way, a drone making it through the weaknesses in one system can be defeated by the next slice of cheese.

Jamey Jacob receives funding from the Depts. of Defense and Homeland Security to evaluate Counter-UAS capabilities and UAS threats. He is affiliated with AUVSI, the Association of Unmanned Vehicle Systems International (AUVSI).

– ref. Counter-drone technologies are evolving – but there’s no surefire way to defend against drone attacks – https://theconversation.com/counter-drone-technologies-are-evolving-but-theres-no-surefire-way-to-defend-against-drone-attacks-229595

Source: The Conversation – USA (2) – By Gary W. Yohe, Professor of Economics and Environmental Studies, Wesleyan University

In 2009 the U.S. Environmental Protection Agency formally declared that greenhouse gas emissions, including from vehicles and industry, endanger public health and welfare. The decision, known as the endangerment finding, was based on years of evidence, and it has underpinned EPA actions on climate change ever since.

The Trump administration is now tearing up that finding as it tries to roll back climate regulations on everything from vehicles to industries.

“This is as big as it gets,” EPA Administrator Lee Zeldin said in announcing with President Donald Trump on Feb. 12, 2026, that the administration had “terminated” the endangerment finding. Zeldin argued that the finding had “no basis in law.” Trump, smiling next to him, talked about the benefits of fossil fuels and said the finding that greenhouse gas emissions endanger public health and welfare “had no basis in fact. None whatsoever.”

There’s no question that the EPA’s decision will be challenged in court. The legal question over the EPA’s authority to regulate greenhouse gases will be debated, just as it was in 2009. The administration’s claim that the finding was scientifically wrong, however, has no basis in fact.

The world just experienced its three hottest years on record, evidence of worsening climate change is stronger now than ever before, and people across the U.S. are increasingly experiencing the harm firsthand.

Several legal issues have already surfaced that could get in the EPA’s way. They include evidence from emails submitted in a court case that suggest political appointees sought to direct the scientific review that the administration has used to defend its plan, at the exclusion of respected scientific sources. On Jan. 30 a federal judge ruled that the Department of Energy violated the law when it handpicked five researchers to write the climate science review. The ruling doesn’t necessarily stop the EPA, but it raises questions.

To understand what happens now, it helps to look back at history for some context.

The Supreme Court started it

The endangerment finding stemmed from a 2007 U.S. Supreme Court ruling in Massachusetts v. EPA.

The court found that various greenhouse gases, including carbon dioxide, were “pollutants covered by the Clean Air Act,” and it gave the EPA an explicit set of instructions.

The court wrote that the “EPA must determine whether or not emissions from new motor vehicles cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare.”

But the Supreme Court did not order the EPA to regulate greenhouse gas emissions. Only if the EPA found that emissions were harmful would the agency be required, by law, “to establish national ambient air quality standards for certain common and widespread pollutants based on the latest science” – meaning greenhouse gases.

The EPA was required to follow formal procedures – including reviewing the scientific research, assessing the risks and taking public comment – and then determine whether the observed and projected harms were sufficient to justify publishing an “endangerment finding.”

That process took two years. EPA Administrator Lisa Jackson announced on Dec. 7, 2009, that the then-current and projected concentrations of six key greenhouse gases in the atmosphere – carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride – threatened the public health and welfare of current and future generations.

Challenges to the finding erupted immediately.

Jackson denied 10 petitions received in 2009-2010 that called on the administration to reconsider the finding.

On June 26, 2012, the U.S. Court of Appeals for the D.C. Circuit upheld the endangerment finding and regulations that the EPA had issued under the Clean Air Act for passenger vehicles and permitting procedures for stationary sources, such as power plants.

This latest challenge is different.

It came directly from the Trump administration without going through normal channels. It was, though, entirely consistent with both the conservative Heritage Foundation’s Project 2025 plan for the Trump administration and President Donald Trump’s dismissive perspective on climate risk.

Trump’s burden of proof

To legally reverse the 2009 finding, the agency was required to go through the same evaluation process as before. According to conditions outlined in the Clean Air Act, the reversal of the 2009 finding must be justified by a thorough and complete review of the current science and not just be political posturing.

That’s a tough task.

Energy Secretary Chris Wright has talked publicly about how he handpicked the five researchers who wrote the scientific research review. A judge has now found that the effort violated the 1972 Federal Advisory Committee Act, which requires that agency-chosen panels providing policy advice to the government conduct their work in public.

All five members of the committee had been outspoken critics of mainstream climate science. Their report, released in summer 2025, was widely criticized for inaccuracies in what they referenced and its failure to represent the current science.

Scientific research available today clearly shows that greenhouse gas emissions harm public health and welfare. Importantly, evidence collected since 2009 is even stronger now than it was when the first endangerment finding was written, approved and implemented.

For example, a 2025 review by the National Academies of Sciences, Engineering and Medicine determined that the evidence supporting the endangerment finding is even stronger today than it was in 2009. A 2019 peer-reviewed assessment of the evidence related to greenhouse gas emissions’ role in climate change came to the same conclusion.

The Sixth Assessment of the Intergovernmental Panel on Climate Change, a report produced by hundreds of scientists from around the world, found in 2023 that “adverse impacts of human-caused climate change will continue to intensify.”

In other words, greenhouse gas emissions were causing harm in 2009, and the harm is worse now and will be even worse in the future without steps to reduce emissions.

In public comments on the Department of Energy’s problematic 2025 review, a group of climate experts from around the world reached the same conclusion, adding that the Department of Energy’s Climate Working Group review “fails to adequately represent this reality.”

What happens now that the EPA has dropped the endangerment finding

As an economist who has studied the effects of climate change for over 40 years, I am concerned that the EPA’s rescinding the endangerment finding will lead to faster efforts to roll back U.S. climate regulations meant to slow climate change.

It will also give the administration cover for further actions that would defund more science programs, stop the collection of valuable data, freeze hiring and discourage a generation of emerging science talent.

Cases typically take years to wind through the courts, but both the Environmental Defense Fund and the Union of Concerned Scientists expect to file lawsuits quickly once the rescission is published in the Federal Register.

Unless a judge issues an injunction, I expect to see an accelerating retreat from U.S. efforts to reduce climate change. For example, consider the removal in early February of the climate science chapter from a new “Reference Manual on Scientific Evidence” that advises judges. Republican state attorneys general had complained to the Federal Judicial Center of the National Academies of Science, Engineering, and Medicine that the manual “treated human influence on climate as fact.” But it is fact. That is not just my opinion. The National Academies itself said so in 2020 and again in 2025.

I see no scenario in which a legal challenge doesn’t end up before the Supreme Court. I would hope that both the enormous amount of scientific evidence and the words in the preamble of the U.S. Constitution would have some significant sway in the court’s considerations. It starts, “We the People of the United States, in Order to form a more perfect Union,” and includes in its list of principles, “promote the general Welfare.

This article, originally published Feb. 2, 2026, has been updated with EPA rescinding the endangerment finding.

Gary W. Yohe does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. EPA rescinds 2009 endangerment finding, clearing way for Trump to shred more US climate rules – but serious court challenges await – https://theconversation.com/epa-rescinds-2009-endangerment-finding-clearing-way-for-trump-to-shred-more-us-climate-rules-but-serious-court-challenges-await-274194

Source: The Conversation – USA (3) – By Jonathan Levy, Professor and Chair, Department of Environmental Health, Boston University

The Trump administration took a major step in its efforts to unravel America’s climate policies on Feb. 12, 2026. It moved to rescind the 2009 endangerment finding, a formal determination that greenhouse gas emissions, such as carbon dioxide and methane from burning fossil fuels, endanger public health and welfare. But the administration’s arguments in dismissing the health risks of climate change are not only factually wrong, they’re deeply dangerous to Americans’ health and safety.

As physicians, epidemiologists and environmental health scientists, we’ve seen growing evidence of the connections between climate change and harm to people’s health.

Here’s a look at the health risks everyone face from climate change.

Extreme heat

Greenhouse gases from vehicles, power plants and other sources accumulate in the atmosphere, trapping heat and holding it close to Earth’s surface like a blanket. Too much of it causes global temperatures to rise, leaving more people exposed to dangerous heat more often.

Most people who get minor heat illnesses will recover, but more extreme exposure, especially without enough hydration and a way to cool off, can be fatal. People who work outside, are elderly or have underlying illnesses such as heart, lung or kidney diseases are often at the greatest risk.

Heat deaths have been rising globally, up 23% from the 1990s to the 2010s, when the average year saw more than half a million heat-related deaths. Here in the U.S., the 2021 Pacific Northwest heat dome killed hundreds of people.

Climate scientists predict that with advancing climate change, many areas of the world, including U.S. cities such as Miami, Houston, Phoenix and Las Vegas, will confront many more days each year hot enough to threaten human survival.

Extreme weather

Warmer air holds more moisture, so climate change brings increasing rainfall and storm intensity and worsening flooding, as many U.S. communities have experienced in recent years. Warmer ocean water also fuels more powerful hurricanes.

Increased flooding carries health risks, including drownings, injuries and water contamination from human pathogens and toxic chemicals. People cleaning out flooded homes also face risks from mold exposure, injuries and mental distress.

Climate change also worsens droughts, disrupting food supplies and causing respiratory illness from dust. Rising temperatures and aridity dry out forests and grasslands, making them a setup for wildfires.

Air pollution

Wildfires, along with other climate effects, are worsening air quality around the country.

Wildfire smoke is a toxic soup of microscopic particles (known as fine particulate matter, or PM2.5) that can penetrate deep in the lungs and hazardous compounds such as lead, formaldehyde and dioxins generated when homes, cars and other materials burn at high temperatures. Smoke plumes can travel thousands of miles downwind and trigger heart attacks and elevate lung cancer risks, among other harms.

Meanwhile, warmer conditions favor the formation of ground-level ozone, a heart and lung irritant. Burning of fossil fuels also generates dangerous air pollutants that cause a long list of health problems, including heart attacks, strokes, asthma flare-ups and lung cancer.

Infectious diseases

Because they are cold-blooded organisms, insects are directly influenced by temperature. So with rising temperatures, mosquito biting rates rise as well. Warming also accelerates the development of disease agents that mosquitoes transmit.

Mosquito-borne dengue fever has turned up in Florida, Texas, Hawaii, Arizona and California. New York state just saw its first locally acquired case of chikungunya virus, also transmitted by mosquitoes.

And it’s not just insect-borne infections. Warmer temperatures increase diarrhea and foodborne illness from Vibrio cholerae and other bacteria and heavy rainfall increases sewage-contaminated stormwater overflows into lakes and streams. At the other water extreme, drought in the desert Southwest increases the risk of coccidioidomycosis, a fungal infection known as valley fever.

Other impacts

Climate change threatens health in numerous other ways. Longer pollen seasons increase allergen exposures. Lower crop yields reduce access to nutritious foods.

Mental health also suffers, with anxiety, depression and post-traumatic stress following disasters, and increased rates of violent crime and suicide tied to high-temperature days.

Young children, older adults, pregnant women and people with preexisting medical conditions are among the highest-risk groups. Lower-income people also face greater risk because of higher rates of chronic disease, higher exposures to climate hazards and fewer resources for protection, medical care and recovery from disasters.

Policy-based evidence-making

The evidence linking climate change with health has grown considerably since 2009. Today, it is incontrovertible.

Studies show that heat, air pollution, disease spread and food insecurity linked to climate change are worsening and costing millions of lives around the world each year. This evidence also aligns with Americans’ lived experiences. Anybody who has fallen ill during a heat wave, struggled while breathing wildfire smoke or been injured cleaning up from a hurricane knows that climate change can threaten human health.

Yet the Trump administration is willfully ignoring this evidence in proclaiming that climate change does not endanger health.

Its move to rescind the 2009 endangerment finding, which underpins many climate regulations, fits with a broader set of policy measures, including cutting support for renewable energy and subsidizing fossil fuel industries that endanger public health. In addition to rescinding the endangerment finding, the Trump administration also moved to roll back emissions limits on vehicles – the leading source of U.S. carbon emissions and a major contributor to air pollutants such as PM2.5 and ozone.

It’s not just about endangerment

The evidence is clear: Climate change endangers human health. But there’s a flip side to the story.

When countries work to reduce the causes of climate change, they help tackle some of the world’s biggest health challenges. Cleaner vehicles and cleaner electricity mean cleaner air – and less heart and lung disease. More walking and cycling on safe sidewalks and bike paths mean more physical activity and lower chronic disease risks. The list goes on. By confronting climate change, we promote good health.

To really make America healthy, in our view, the nation should acknowledge the facts behind the endangerment finding and double down on our transition from fossil fuels to a healthy, clean energy future.

This article includes material from a story originally published Nov. 12, 2025.

Jonathan Levy receives funding from the National Institutes of Health, the Federal Aviation Administration, the City of Boston, the Masschusetts Office of the Attorney General, and the Mosaic Foundation.

Howard Frumkin has no financial conflicts of interest to report. He is a member of advisory boards (or equivalent committees) for the Planetary Health Alliance; the Harvard Center for Climate, Health, and the Global Environment; the Medical Society Consortium on Climate Change and Health; the Global Consortium on Climate and Health Education; the Yale Center on Climate Change and Health; and EcoAmerica’s Climate for Health program, and chairs the National Academy of Medicine Committee on the Roadmap for Transformative Action to Achieve Health for All at Net-Zero Emissions—all voluntary unpaid positions.

Jonathan Patz receives funding from the National Institutes of Health. He is affiliated with the Medical Society Consortium for Climate and Health, and its affiliate Healthy Climate Wisconsin.

Vijay Limaye is affiliated with the Natural Resources Defense Council.

– ref. Trump says climate change doesn’t endanger public health – evidence shows it does, from extreme heat to mosquito-borne illnesses – https://theconversation.com/trump-says-climate-change-doesnt-endanger-public-health-evidence-shows-it-does-from-extreme-heat-to-mosquito-borne-illnesses-275619

Source: The Conversation – USA (3) – By Ana Santos Rutschman, Professor of Law, Villanova University

The Food and Drug Administration has refused to review an application from the biotech company Moderna to approve its mRNA-based flu vaccine.

The agency’s decision, which Moderna announced in a press release on Feb. 10, 2026, is the latest step in efforts by federal health officials under Health and Human Services Secretary Robert F. Kennedy Jr. to disrupt longstanding public health practices relating to vaccine access and approval, as well as to reshape the public’s perception of vaccine safety.

Vaccines based on mRNA came to the forefront in the early days of the COVID-19 pandemic, but researchers are now using the technology to create other vaccines, as well as treatments for diseases such as cancer and autoimmune disorders. The Nobel Prize-winning technology may be especially promising for flu because vaccines can be developed rapidly each season to match mutating influenza strains.

However, Kennedy and other federal health officials, including at the FDA, have expressed particular skepticism toward mRNA-based vaccines, raising safety concerns while providing no credible data on their health risks, and defunding research on their development.

The Conversation asked Ana Santos Rutschman, a Villanova University law professor and vaccine policy expert, to explain the significance of the FDA’s decision and how it fits into the rapidly changing landscape of public health policy.

What exactly did the FDA do, and why is it unusual?

In December 2025, Moderna submitted an application to the FDA to approve an mRNA flu vaccine for adults age 50 and older. The vaccine had been tested in clinical trials including more than 40,000 people. In response to the application, the agency sent Moderna a “refusal-to-file” letter, dated Feb. 3, 2026. This is a type of notice the regulator sends to companies when it deems a new drug or vaccine’s application to be incomplete.

Because companies developing new products meet with the FDA early in the process to agree on requirements for approval, it’s rare for the agency to take this action. What’s more, there have been very few occasions in which the FDA has diverged significantly from other major drug regulators around the world. But in this case, drug regulators in Canada, Europe and Australia accepted Moderna’s application for review.

Especially concerning is that several FDA scientists and other staff have confirmed that they expected to review Moderna’s application. The director of the FDA’s Office of Vaccines Research and Review, David Kaslow, wrote a memo recommending it be reviewed. But Vinay Prasad, who directs the center that oversees the vaccine research office, overruled the decision.

Directors rarely overrule agency scientists, especially regarding vaccines. But this is at least the fourth time Prasad has done so since being appointed to the FDA in 2025.

What reasons did the FDA give for its decision?

Moderna took the unusual step of announcing the FDA’s refusal and releasing the agency’s letter. The letter states that Moderna did not conduct an “adequate and well-controlled” study because it had not compared patients receiving its vaccine to patients receiving what the agency claimed to be “the best-available standard of care.”

In the U.S., standard-dose flu vaccines are approved for everyone over 6 months of age, but health authorities recommend that adults over 65 receive a more potent dose. Moderna’s announcement quoted the language the FDA used when approving the company’s clinical trial protocol in 2024. The agency had originally suggested that for people age 65 and older, the company compare the efficacy of its vaccine to the more potent dose. But after reviewing Moderna’s protocol, the FDA deemed the standard vaccine “acceptable.”

Besides the fact that the FDA agreed to the trials Moderna conducted, I believe the agency’s claim that the company didn’t use “the best-available standard of care” is problematic because it does not reflect the legal requirements for vaccine approval. Although this phrase sounds official, it is nowhere to be found in FDA law or guidance for companies developing vaccines.

Instead, FDA law requires a company to provide data from “adequate and well controlled studies” and using standard dose flu vaccines aligns with the requirement because they are widely used across age groups.

Shortly after Moderna announced the refusal, the health news outlet STAT quoted an unnamed FDA official stating that if Moderna were to “show some humility,” the agency might still review the application, but only for people under 65. Imposing this restriction after refusing to review the application has no basis in the law because FDA approves clinical trial parameters early on, in consultation with companies.

From a legal perspective, the FDA’s decision could potentially meet what’s called the “arbitrary and capricious” standard, because the agency seems to have altered its position without a valid reason for that change. If a court makes such a determination, it could invalidate the FDA’s decision. That process, however, would take time.

Does the FDA’s decision reflect a change in vaccine policy?

This is the first time that the FDA has tried to preclude the review of a vaccine for reasons that do not have to do with safety or efficacy. The move, which ties into a broader strategy by federal health officials under Kennedy, signals an escalation in the agency’s efforts to intervene in established procedures for testing vaccines.

In April 2025, Kennedy announced that new vaccines would require additional clinical trials. In November 2025, Prasad released an internal FDA memo claiming that mRNA-based COVID-19 vaccines had killed children. Although he provided no evidence, he said that in response to the alleged deaths, large-scale changes to requirements for vaccine approval were coming.

The FDA’s refusal of Moderna’s application appears to be Prasad’s policy in action.

What might this mean for vaccines going forward?

On a practical level, the fact that the FDA is now articulating requirements that are nowhere to be found in the law creates major uncertainty for companies with pending or upcoming vaccine applications. That’s because manufacturers now have reason to worry that they might invest resources in the lengthy process of developing a vaccine, only to receive similarly unpredictable refusals.

More broadly, with so many areas in vaccine law and policy in turmoil, incentives for vaccine manufacturers to bring vaccines to market are shrinking. In January 2026, even before the flu vaccine refusal, Moderna’s chief executive officer said the company was scaling back on vaccine development .

Finally, the FDA’s move risks fueling further mistrust in vaccines, aligning with a wider push from federal health officials to question long-settled science.

Ana Santos Rutschman does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. FDA rejects Moderna’s mRNA flu vaccine application – for reasons with no basis in the law – https://theconversation.com/fda-rejects-modernas-mrna-flu-vaccine-application-for-reasons-with-no-basis-in-the-law-275771

Source: The Conversation – USA – By Eric Yttri, Associate Professor of Biological Sciences, Carnegie Mellon University

At the Winter Olympics, skiers, bobsledders, speedskaters and many other athletes all have to master one critical moment: when to start. That split second is paramount during competition because when everyone is strong and skilled, a moment of hesitation can separate gold from silver. A competitor who hesitates too much will be left behind – but moving too early will get them disqualified.

Though the circumstances are less intense, this paradox of hesitation applies to daily life. Waiting for the right moment to cross the street, or pausing before deciding whether to answer a call from a number you don’t recognize, are daily examples of hesitation. Importantly, some psychiatric conditions such as obsessive-compulsive disorder are characterized by impulsivity, or a lack of hesitation, while excessive hesitation is a crippling consequence of several anxiety disorders.

As a neuroscientist, I have been working to uncover how the brain decides when to act and when to wait. Recent research from my team and me helps explain why this split-second pause happens, offering insight not only into elite athletic performance, but also how people make everyday decisions when the potential outcome isn’t clear.

We found that the key to hesitation is a response to uncertainty. This could be where a dropped hockey puck will land, when a race starts, or placing your order at a new restaurant.

Hesitation and the brain

To understand how the brain controls hesitation, my colleagues and I designed a simple decision-making task in mice.

The task required the mouse’s brain to interpret signals that were predictably good, predictably bad or – most importantly – uncertain, meaning somewhere in between. Different auditory tones indicated whether a drop of sugar water would soon be delivered, not delivered, or had a 50/50 chance of delivery.

How the mice behaved would not affect the outcome. Nevertheless, mice would still wait longer before licking to see whether a reward had been given in the uncertain scenario. Just like in people, unpredictable situations led to delays in response. This hesitation was not the result of vacillating between options in indecision, but an active and regulated brain process to pause before acting due to environmental uncertainty.

When we examined neural activity associated with the onset of licking, we identified a specific group of neurons that became active only when outcomes were unclear. Those neurons effectively controlled whether the brain should commit to an action or pause to gather more information. The degree to which these neurons were active could predict whether mice would hesitate before making a decision.

To confirm that these neurons played a role in controlling hesitation, we used a technique called optogenetics to briefly turn these brain cells on or off. When we activated the neurons, mice hesitated more. When we silenced them, that hesitation faded and their responses were quicker by several hundred milliseconds, in line with their reactions to predictable situations.

Daily life, disease and downhill racing

Our findings suggest that, rather than a weakness to overcome, hesitation appears to be a fundamental brain feature that helps people and animals navigate an uncertain world and avoid costly mistakes.

Our study also provides insights into the balance of action and inaction in health and disease. The hesitation neurons are located in the basal ganglia, the same part of the brain affected in Parkinson’s disease, OCD and addiction. While researchers must still determine how much overlap or interaction there is between the cells involved in hesitation and those affected in psychiatric disorders, their overlap in circuitry points to possible targets for treatment.

Our next step is to understand how cells controlling hesitation interact with drugs treating ADHD and OCD, conditions where patients can respond impulsively during volatile or uncertain situations.

We also aim to identify which brain areas provide these cells with information about uncertainty – the environmental signal so critical to hesitation. While researchers have found that several parts of an area of the brain called the prefrontal cortex encode uncertainty, it’s unclear how the brain actually makes use of this information, where the rubber meets the road.

Hesitation is not a flaw – it’s a critical feature for navigating an unpredictable world. Whether you’re a figure skater waiting for the perfect moment to launch your jump or just going about your day, the circuitry behind hesitation plays an important role in figuring out the timing to get the action right.

Eric Yttri receives funding from the National Institute of Health and the Binational Science Foundation.

– ref. Hesitation is costly in sports but essential to life – neuroscientists identified its brain circuitry – https://theconversation.com/hesitation-is-costly-in-sports-but-essential-to-life-neuroscientists-identified-its-brain-circuitry-274680

Source: The Conversation – USA (2) – By Eric Hengyu Hu, Research Scientist of Educational Policy, University at Albany, State University of New York

Families with children who have dyslexia have long pushed lawmakers to respond to a pressing concern: Too many young students struggle for years to learn to read, before schools recognize the problem.

In response, nearly every state in the U.S. passed some sort of dyslexia laws over the past decade. Most of these laws encourage or require schools to screen young children for reading difficulties, train teachers in evidence-based reading instruction and provide targeted support to students who show early signs of dyslexia.

Families of children with dyslexia, educators and dyslexia advocacy groups widely praised these laws. If schools could identify dyslexia early and respond with evidence-based instruction, reading outcomes would likely improve and fewer children would fall behind.

But what actually happened after these laws passed?

My colleagues and I examined nearly two decades of national student data to answer this question. The results tell a complicated story.

An undetected problem

Dyslexia is a brain-based learning difference that makes reading words slow and effortful, even when children have typical intelligence and education.

About 5% to 15% of U.S. children experience persistent reading difficulties consistent with dyslexia. Without early support, these difficulties can have long-term academic and emotional consequences.

Before the 2000s, dyslexia was rarely mentioned explicitly in education policy. Students with dyslexia were typically grouped under a broad learning disability category, often without focused instruction or support.

Parent advocacy groups and dyslexia advocacy organizations began pushing lawmakers in the early 2010s to recognize dyslexia in state education policy. They also lobbied for states to require early screening for reading difficulties and to teach reading with rigorous methods backed by scientific research.

Their advocacy coincided with a growing scientific consensus: Early, explicit instruction in phonics and language structure helps struggling readers, including students with dyslexia.

Research and advocacy also highlighted that many children with reading difficulties were not identified until later in elementary school, after years of academic struggle, when gaps in reading skills are harder to correct.

States respond with dyslexia laws

A few states, like Texas and Arkansas, first passed dyslexia laws in the early 2010s. One central goal was to help schools identify dyslexia in students earlier, rather than waiting until these students experience repeated academic failure.

By the late 2010s, most states had adopted some form of dyslexia legislation.

As of 2025, all states except Hawaii have enacted dyslexia legislation.

While the laws shared similar goals of promoting early screening for reading difficulties, improving reading instruction and expanding support for struggling readers, they varied widely in strength, funding and expectations for schools.

My colleagues and I wanted to examine whether the wave of state dyslexia laws that began in the early 2010s was associated with changes in students’ reading outcomes.

Mixed results

We analyzed fourth grade reading assessments from the National Assessment of Educational Progress, often called the nation’s report card, from 2003 to 2022.

We focused on how often students were identified with reading-related learning disabilities and how well those students performed in reading. We compared trends before and after dyslexia laws were enacted across 47 states.

Two findings stood out:

• First, more than half of the states with these new laws showed no significant shift in identifying learning disabilities related to reading. Some states identified more students, some fewer, but there was no consistent national pattern.

• Second, reading achievement among students identified with learning disabilities often declined, rather than improved, after these laws passed in many states, including Alaska, Maine, Massachusetts, New York, Ohio and West Virginia.

Only four states – Arizona, Mississippi, Nevada and Oklahoma – showed significant gains in reading scores on state assessments, with average increases ranging from 3 points in Oklahoma’s case to 10 points in Arizona’s example. Many other states experienced flat trends or declines over the same period.

Passing a law doesn’t equal classroom change

Our findings suggest that dyslexia laws often raised awareness about dyslexia and early reading difficulties without fully changing classroom practices.

Many states, such as Connecticut, Maine, Massachusetts and North Carolina, required early screening for dyslexia – but did not ensure schools had trained staff, for example, on how to conduct this screening.

Even with enough teachers to screen for dyslexia, screening alone does not help students unless it is followed by high-quality instruction and sustained support.

Funding has been another major challenge. Most dyslexia laws were passed without dedicated funding for teacher training or instructional materials, leaving districts to absorb the costs. As a result, implementation has been uneven, with well-funded districts moving faster than others.

Teacher preparation also matters. Teaching reading effectively, especially for students with dyslexia, requires specialized knowledge that many teachers were never taught in their training programs. Without strong professional development and ongoing coaching, new mandates can be difficult to carry out.

Taken together, these factors help explain why dyslexia laws alone have not produced widespread gains.

What distinguishes states that improved

Despite the mixed national picture, students in some states, including Arizona and Mississippi, did better on reading outcomes after their schools adopted dyslexia-related policies. These states shared several features.

First, when young children in these states were flagged as at risk for reading difficulties, schools were expected to provide additional reading instruction – rather than treating screening as an end in itself.

Second, schools in these states invested in practical teacher training, focused on how to teach foundational reading skills – such as phonics and word decoding – that are especially important for students with dyslexia.

Third, these states aligned their dyslexia laws with broader literacy reforms – like using evidence-based reading curricula and providing coaching to teachers – rather than treating dyslexia policy as a stand-alone mandate.

Mississippi is often cited as an example of a state that successfully paired dyslexia policy with a broader overhaul of reading instruction, resulting in a boost in reading achievement scores from 2013 to 2019. This overhaul included more structured reading instruction, teacher training and literacy coaches in schools.

Other states, including Louisiana and Alabama, adopted similar approaches and also saw reading gains for kids with learning disabilities – including dyslexia – after they enacted their dyslexia laws.

The takeaway

Dyslexia laws recognize that struggling young readers deserve early, evidence-based support rather than years of delay. That alone is meaningful progress.

But two decades of national data suggests that legislation by itself is not enough.

If states want dyslexia laws to fulfill their promise, the next step is clear: Move beyond mandates and focus on how schools are supported to carry them out. For children struggling to learn to read, the difference between policy and practice can shape their entire educational future.

Eric Hengyu Hu does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Nearly every state in the US has dyslexia laws – but our research shows limited change for struggling readers – https://theconversation.com/nearly-every-state-in-the-us-has-dyslexia-laws-but-our-research-shows-limited-change-for-struggling-readers-275202

Source: The Conversation – USA (2) – By Alcina Johnson Sudagar, Research Scientist in Chemistry, Washington University in St. Louis

Concrete is all around you – in the foundation of your home, the bridges you drive over, the sidewalks and buildings of cities. It is often described as the second-most used material by volume on Earth after water.

But the way concrete is made today also makes it a major contributor to climate change.

Portland cement, the key component of concrete, is responsible for about 8% of global greenhouse gas emissions. That’s because it’s made by heating limestone to high temperatures, a process that burns a large amount of fossil fuels for energy and releases carbon dioxide from the limestone in the process.

The good news is that there are alternatives, and they are gaining attention.

Portland cement: A greenhouse gas problem

Cementlike substances have been used in construction for thousands of years. Architects have found evidence of their use in the pyramids of Egypt and the buildings and aqueducts of the Roman Empire.

The Portland cement commonly used in construction today was patented in 1824 by Joseph Aspdin, a British bricklayer.

Modern cement preparation starts with crushing the excavated raw materials limestone and clay and then heating them in a kiln at around 2,650 degrees Fahrenheit (about 1,450 degrees Celsius) to form clinker, a hard, rocklike residue. The clinker is then cooled and ground with gypsum into a fine powder, which is called cement.

About 40% of the carbon dioxide emissions from cement production come from burning fossil fuels to generate the high heat needed to run the kiln. The rest come as the heat converts limestone (calcium carbonate) to lime (calcium oxide), releasing carbon dioxide.

In all, between half a ton and 1 ton of greenhouse gas is released per ton of Portland cement. Cement is a binding agent that, mixed with water, holds aggregate together to create concrete. It makes up about 10% to 15% of the concrete mix by weight.

Alternative technologies can lower emissions

As populations, cities and the need for new infrastructure expand, the use of cement is growing, making it important to find alternatives with lower environmental costs.

Some techniques for reducing carbon dioxide emissions include substituting some of the clinker – the hard residue typically made from limestone – with supplementary materials such as clay, or fly ash and slag from industries. Other methods reduce the amount of cement by mixing in waste sawdust or recycled materials like plastics.

The long-term solution for reducing cement’s emissions, however, is to replace traditional cement completely with alternatives. One option is geopolymers made from earthen clay and industrial wastes.

Geopolymers: A more climate-friendly solution

Geopolymers can be made by mixing claylike materials that are rich in aluminum and silicon minerals with a chemical activator through a process called geopolymerization. The activator transforms the silicon and aluminum into a structure that will look like cement. All of this can happen at room temperature.

The major difference between cement and geopolymer is that cement is mainly made of calcium, whereas geopolymers are made of silicon and aluminum with some possible calcium in their structure.

These geopolymers have been found to possess high strength and durability, including resilience in freeze-thaw cycles and resistance to heat and fire, which are important requirements in construction. Studies have found that some geopolymers can provide comparable if not better strength than traditional cement and, because they don’t require heat the way clinker does, they can be produced with significantly lower greenhouse gas emissions.

Geopolymers can also be produced from a variety of raw materials rich in aluminum and silicon, including earthen clays, fly ash, blast furnace slag, rice husk ash, iron ore wastes and recycled construction brick waste. Geopolymer technology can be adapted depending on the clay or industrial waste locally available in a region.

An added advantage of geopolymers is that changes to the mixture can produce a range of features.

For example, I and my co-researchers at the University of Aveiro in Portugal added a small amount of cork industry waste – the leftovers from creating bottle corks – to clay-based geopolymer and found it could improve the strength of the material by up to twofold. The cork particles filled the spaces in the geopolymer structure, making it denser, which increased the strength.

Similarly, additives such as sisal fibers from the agave plant, recycled plastic and steel fibers can change geopolymer properties. The additives do not participate in the geopolymerization process but act as fillers in the structure.

The structure of geopolymers can also be designed to act as adsorbents, attracting toxic metals in wastewater and capturing and storing radioactive wastes. Specifically, incorporating materials like zeolite that are natural adsorbents in the geopolymer structure can make them useful for such applications as well.

Where geopolymers are used now

Geopolymers have been used in many types of construction, including roads, coatings, 3D printing, coastal environmental protection, the steel and chemical industries, sewer rehabilitation and building radiation shielding and rocket launchpad and bunker infrastructure.

One of the earliest examples of a modern geopolymer concrete project was the Brisbane West Wellcamp airport in Australia.

It was built in 2014 with 70,000 metric tons of geopolymer concrete, which was estimated to have reduced the project’s carbon dioxide emissions by as much as 80%.

The geopolymer market is currently estimated to be between US$7 billion and $10 billion, with the largest growth in the Asia-Pacific region.

Analysts have estimated that the market could grow at a rate of 10% to 20% per year and reach about $62 billion by 2033.

In several countries, greenhouse gas regulations and green-building certifications are expected to support the continued growth of geopolymers in the construction industry.

Expanding the use of cement alternatives

The advantage of using industrial wastes in geopolymers is a double-edged sword, however. The composition of industrial wastes varies, so it can be difficult to standardize the processing methods. The geopolymer components need to be mixed in particular ratios to achieve desired properties.

Producing the activator for the geopolymer, typically done in chemical facilities, can raise the cost and contribute to the carbon footprint. And the long-term data about these materials’ stability is only now being developed given their newness. Also, these geopolymers can take longer to set than cement, though the setting time can be sped up by using raw materials that react quickly.

Developing cheaper, naturally available activators like agricultural waste rice husk with sustainable supply chains could help lower the costs and environmental impact. Also, printing the recipe on the raw material packaging could help simplify the job of determining the mixing ratio so geopolymers can be more widely used with confidence.

Even though geopolymer technology has some drawbacks, these low-carbon alternatives have great potential for reducing emissions from the construction sector.

Alcina Johnson Sudagar has received funding from GeoBioTec.

– ref. Polymers from earth can make cement more climate-friendly – https://theconversation.com/polymers-from-earth-can-make-cement-more-climate-friendly-270354