Noah Diffenbaugh testifies in Congressional climate hearing

On May 23, Stanford climate scientist Noah Diffenbaugh testified before the U.S. House Select Committee on the Climate Crisis, explaining the scientific realities of climate change and its impacts on the United States. 

"The good news for our country is that although climate change is already impacting Americans, there are many opportunities for us to become more resilient, and in doing so build a more vibrant, secure and equitable nation," said Diffenbaugh, the Kara J Foundation Professor at Stanford’s School of Earth, Energy & Environmental Sciences.

The hearing, “Creating a Climate Resilient America” was one of many climate-related hearings held this year in the Democrat-controlled House of Representatives. 

“Congressional action is an indispensable component of building solutions to the climate crisis,” said Chris Field, director of the Stanford Woods Institute for the Environment. “Gathering information and exploring options for resilience is an important step toward decisive action.” 

Rep. Kathy Castor, D-FL, opened the hearing with a discussion of the heavy price future generations could pay for inaction.

"The millions of young people who are joining climate strikes tomorrow have never lived in a normal climate – and they know it. That’s why they’re demanding climate action now," said Castor, referring to a global children’s school strike planned for Friday. 

Diffenbaugh, who is also the Kimmelman Family Senior Fellow at the Stanford Woods Institute for the Environment, discussed his recent research on the scientific evidence for the U.S. Environmental Protection Agency’s “Endangerment Finding,” which details how the buildup of heat-trapping greenhouse gases in the atmosphere endangers public health and welfare.

“We found that there is now strong evidence of entirely new kinds of impacts that were not featured in the original finding,” Diffenbaugh said. “These include ocean acidification, interpersonal violence, national security and economic wellbeing.”

The main focus of the hearing rested on the economic damages of climate change. Limiting warming to just 1.5 degrees Celsius compared to 2 degrees Celsius could reduce economic damage in the United States by $6 trillion, and could save the world $20 trillion, according to Diffenbaugh. He explained that if global greenhouse gas emissions continue at current rates, the majority of U.S. counties are likely to suffer negative impacts, including decreased labor productivity, increased crime, increased mortality, higher energy expenditures, coastal damage, and lower crop yields across large swaths of the country.

After some Republican members of the committee pointed to inevitable emissions from other countries as a potential reason to deemphasize stemming U.S. emissions, Diffenbaugh said, “We've had about 1 degree Celsius of global warming already. The United States has contributed about a quarter of the emissions that have led to that warming historically.” The more frequent and intense extreme events hitting Americans in recent years have been influenced by the warming America has caused, he explained.

Rep. Gary Palmer, R-AL, asked whether other factors, such as a shift in magnetic poles, could be affecting the weather. Diffenbaugh responded that scientists are very conservative when it comes to attributing the influence of climate change on extreme events. Even given this high conservatism, he explained, the scales have been tipped for record-breaking heat events for 75 percent of North America and record-breaking wet events for 50 percent of North America.

When asked about infrastructure, Diffenbaugh referred to a report by the California Secretary for Natural Resources’ Climate-Safe Infrastructure Working Group on which he serves. He warned that historical data no longer accurately predicts the likelihood and severity of extreme events, and planning for infrastructure must include an acknowledgment that the climate is changing. 

Other witnesses called before the committee included Rachel Cleetus, Policy Director of the Climate and Energy Program at the Union of Concerned Scientists, Keith Hodges, Member of the Virginia House of Delegates and Matt Russell, Executive Director of the Iowa Interfaith Power and Light, a statewide organization is mobilizing the religious community to become leaders in the movement for climate action.

This hearing came weeks after the House voted 231 to 190 for the Climate Action Now Act (H.R. 9), a bill that seeks to prevent the Trump Administration from withdrawing from the Paris Climate Agreement. 

"The climate crisis isn’t somebody else’s problem. It’s everyone’s problem," Castor said.

Highlights and video of the event are available at the committee’s website.