WASHINGTON, D.C. — On November 1, 2023, the Senate Environment and Public Works (EPW) Committee hled a hearing on extreme event attribution, a field of science studying the influence of human-caused climate change on individual extreme weather events, and the impacts of those events on U.S. communities.

Below is the opening statement of Chairman Tom Carper (D-Del.), as prepared for delivery:

“Today, we are here to discuss a field of climate science known as ‘extreme event attribution.’ In fact, I’m told that this is the first-ever congressional hearing on this topic. To understand why we are holding today’s hearing, I think it’s important to ask and answer a few questions.

“First, what is extreme event attribution anyway? Besides being quite a mouthful, extreme event attribution looks at how a specific extreme weather event, such as a particular heat wave or flood, was made worse by climate change.

“Second, why is this kind of climate science so important? To answer that question, we need to first acknowledge the fact that human-caused climate change is increasing the frequency of extreme weather events.

“Earlier this year, the American Meteorological Society issued a report by many of our nation’s leading climate scientists and meteorologists. That report detailed how climate change has driven unprecedented heat waves, floods, and droughts in recent years. We know that continues to be the case.

“And, when Phoenix, Arizona experiences an unprecedented 31 days of temperatures at or above 110 degrees Fahrenheit — as they did this summer — or when historic rainfall leads to severe flooding in places like Florida and Vermont — as it did this year — many of us find ourselves asking, ‘Is climate change to blame for this?’ And, the answer is yes.

“Now, it’s true that we have always had heat waves and floods. But, it’s also true that climate change is making them more intense. So, the better question to ask ourselves is, ‘How much worse did climate change make this heat wave or flood?’ That is the type of question that extreme event attribution scientists — including one of our witnesses, Dr. Wehner — work to answer. 

“These questions matter because the human harms and costs of climate change are massive, and they are growing. As many of our colleagues know, I represent the lowest-lying state in our nation. In Delaware, we are already losing our dunes and wetlands to sea level rise and nor'easters. And, as we work to repair our homes, businesses, and infrastructure and replenish our beaches damaged by these events, we are already paying for the costs of climate change. 

“But, this isn’t just about Delaware. Americans in every state — and, indeed people around the world — are grappling with the costs of climate change. Today, we are going to focus on how it’s fueling extreme weather and what we can do about it.

“Now, in one sense, climate change is already affecting every aspect of our weather. Overall, NASA tells us that global temperatures have increased a little more than 1 degree Celsius — or 2 degrees Fahrenheit — since 1880. That is due mostly to human-caused climate change. Because our planet is warmer, on average, the hot days are becoming hotter. And, because a warmer atmosphere holds more water vapor, rain storms are growing more intense. Warmer oceans are also producing stronger hurricanes. Last week, we saw Hurricane Otis wreak devastation in Mexico when it rapidly intensified from a Category 1 to a Category 5 storm in just nine hours.

“But, you and I don’t experience planetary averages. We live through, clean up from, and pay for specific weather disasters. Extreme event attribution science helps us explain those events.

“So, recognizing that we — as a planet — must prepare for more frequent and intense weather in the future, we — as elected leaders — also need to understand what to expect in our state or our community.

“How much worse will our heat waves become in the years to come? How likely is it that a community will experience an even larger flood next time? Extreme event attribution science is helping us answer those questions, as well. The ability to do so will be critical as we plan future infrastructure projects, anticipate electricity demand, and design better worker protections. Making more informed policy decisions will help us protect more Americans from extreme weather and allow us to use taxpayer dollars more effectively.

“Let me close by reminding everyone that while climate change is driving extreme weather, we are not helpless. This situation is not hopeless. Working together we can prevent the worst impacts of global warming by reducing greenhouse gas emissions. And, we are!

“Thanks to the Bipartisan Infrastructure Law and Inflation Reduction Act, we are turning this adversity into opportunity. Importantly, we are doing so in a way that invests in American-made clean energy, lowers energy costs, creates good-paying jobs, and makes communities more resilient.

“Still, it’s important to acknowledge that we have much more work ahead of us to tackle this challenge. So, as we take steps to better prepare for extreme weather and manage its impacts, extreme event attribution can be an important tool.

“With that, I look forward to hearing from our witnesses today about how communities can better understand and anticipate what is coming and increase their resilience to climate-fueled extreme weather.”