More than 30 scientific organizations sent an open letter to Congress reiterating the consensus behind climate science and calling for a reduction in greenhouse gas emissions.

“Observations throughout the world make it clear that climate change is occurring, and rigorous scientific research concludes that the greenhouse gases emitted by human activities are the primary driver. This conclusion is based on multiple independent lines of evidence and the vast body of peer-reviewed science,” the letter states. “For the United States, climate change impacts include greater threats of extreme weather events, sea level rise, and increased risk of regional water scarcity, heat waves, wildfires, and the disturbance of biological systems. The severity of climate change impacts is increasing and is expected to increase substantially in the coming decades.”

Signed by such groups as the American Chemical Society, the American Association for the Advancement of Science, the Crop Science Society of America, and the Consortium for Ocean Leadership, the letter warns that to avoid the most severe risks, “greenhouse gas emissions must be substantially reduced” and “adaptation is necessary to address unavoidable consequences for human health and safety, food security, water availability, and national security.”

The scientific community offered to work with Congress “to address the challenges of our changing climate.”