As scientists and organizations from dozens of disciplines with deep experience in climate change and its impacts on our planet, we affirm that climate change, which is unequivocally driven by human activities that increase greenhouse gas (GHG) emissions, is endangering human health and welfare in the United States and globally.

In 2009, the U.S. Environmental Protection Agency (EPA) issued a comprehensive scientific "endangerment" finding that GHGs endanger public health and welfare. The agency created the document after an exhaustive review of U.S. and international peer-reviewed climate assessments and in response to a U.S. Supreme Court decision that ordered the review as a precursor to regulating GHGs under the U.S. Clean Air Act.

In 2025, the Trump Administration has now proposed to overturn the endangerment finding, based on an inaccurate and cherry-picked Department of Energy report, even though decades of rigorous, peer-reviewed science leave no room for doubt. The climate is changing faster than ever before, driven by human activities, and the resulting impacts on people and the world we depend on are becoming ever more dire. Greenhouse gases are at higher concentrations than at any time in the last 800,000 years, and the planet’s ten warmest years since 1850 have occurred in the past decade, with 2024 being the hottest. The evidence has only gotten stronger in the last two decades, as Earth observations have expanded, climate models have become more sophisticated, and advanced methods now directly link human activity to extreme weather events and other natural disasters.

The changing climate is directly causing or exacerbating global average temperature increases and heat waves, sea level rise and storm surge, and ocean acidification, and is causing extreme weather events such as hurricanes, floods, wildfires, and drought to occur with greater frequency, intensity, or both.

Climate-related natural disasters, foodborne and waterborne pathogens, and increased allergens have already caused deaths, illnesses, and injuries, and these are projected to get worse. Human welfare is endangered because of increased threats to water resources, food production, infrastructure, and energy access, not to mention the homes, buildings, roads, and bridges that have already been destroyed. Coastal areas have felt the effects of sea level rise and impacts to fisheries; inland regions have suffered severe floods; forest and agriculture areas are affected by fire, drought, and pests; and Indigenous communities have seen their cultures upended.

All of this has cost business revenues and employee jobs, causing financial and social hardships in communities around the United States and the world. These disruptions also drive global conflict and instability, increasing human migration and affecting national security. These are not based on isolated findings — they are the conclusions drawn from thousands of published research articles and confirmed by multiple areas of science.

In 2024 alone, there were 27 confirmed disasters causing more than $1 billion in losses and more than 550 deaths in the United States, including Hurricane Helene that hit North Carolina, Georgia, and Florida – and that’s not accounting for the wildfire that destroyed 11,000 homes in California or the devastating floods in Texas in early 2025. These disasters all bear the fingerprints of climate change. Globally, thousands of people died because of wildfires in Chile, tropical storms in the Philippines and Southeast Asia, floods in Nepal and Spain, and a heat wave in Saudi Arabia.

As scientists, it is our role to highlight and add credible data and information to the substantial record on climate change, partner with communities to improve public health and safety, and fight for evidence-based decision making, especially as the devastating impacts to human health and the environment grow worse.

Any attempts to manipulate or censor climate science – including within the U.S. EPA endangerment finding - will get in the way of the real work to plan for, recover from, and ultimately halt climate change.

The United States—along with every nation on Earth—must confront the reality of climate change with the urgency it demands. This means not only acknowledging the overwhelming scientific consensus but also upholding the integrity of the scientific process. The challenges we face are global, and only by protecting the voices and work of those who seek to understand them can we hope to build a just, livable future for all.