In September 2022, California endured one of its hottest and longest heat waves.
“Our energy grid is being pushed to its max. The risk of outages is real,” Governor Gavin Newsom tweeted. As the need for cooling spiked, California’s electricity demand reached nearly 52,000 megawatts. Many feared ensuing blackouts, which would cause a further spike in heat-related illnesses and fatalities. However, despite the elevated energy usage, the state avoided rolling blackouts due to its past investments in a greener energy grid and responsive policies—including voluntary reductions of power usage.
Climate-driven extreme heat is unavoidable, and its impacts are being felt more frequently around the world. While California was able to avert outages during the September heat wave, it and other at-risk places will have to continue to adopt the necessary tools and resources to prepare for future climatic events.
Arsht-Rock is aiding this effort by developing and deploying solutions that can create climate action at the national and local levels. Arsht-Rock experts contributed to the Climate Insurance Working Group, convened by California Insurance Commissioner Ricardo Lara. Together, they developed recommendations related to extreme heat, which led to the creation of AB2238.
What is AB 2238?
As climate change makes heat waves longer, more frequent, and more intense, action is more urgently needed now than ever. Recognizing the serious threat of heat to the health of Californians, Governor Newsom signed AB 2238 on September 9, one of most substantive pieces of legislation in the United States focused on extreme heat.
Under this bill, the California Environmental Protection Agency will create a statewide heat wave categorization system by January 1, 2025. Arsht-Rock provided technical expertise to the team of specialists and legislators who wrote the bill, sharing its insights into successful models for these systems. The Californian system will rank heat waves by their severity and health impacts, helping local governments to take more efficient and effective action when a heat event strikes. Under the bill, the California Department of Insurance will also conduct a study to understand and quantify the costs of extreme heat events.
One of the great things about… having this example of a law that covers 40 million people is that the language is exportable. Other jurisdictions—states within the U.S. and outside—can take up this health-based warning system.
The adoption of this legislation is both important in addressing climate-driven heat within California and has the potential to have an impact outside of the state. As the fifth largest economy in the world, California is a global leader in climate policy. Often, its models and pilots are replicated and applied in other states and cities. As climate-driven heat waves erupt across the world, AB 2238 serves as a global model for how effectively warning citizens— particularly vulnerable populations—is a necessary first step in reducing fatalities from heat.
How does categorizing heat waves keep people safe?
Effective early warning systems are a steppingstone to protecting people from deadly heat waves. Research shows that ranking extreme weather events increases public perception of risk.
Categorizing and naming is a policy tool that can help the public, first responders, and governments more accurately measure the risk of heat. Temperature alone cannot capture the threat to human health. Arsht-Rock’s systems consider minimum temperatures, humidity, the heat wave’s duration, and recent data from official meteorological service forecasts. This data is combined with historical health measures to identify how dangerous a heat wave will be to a specific community.
Through a health-based categorization system, people are empowered with clear categories that help them understand how dangerous a forecasted heatwave is expected to be in their city. By putting health at the center of extreme heat response, AB 2238 will help reduce heat illness and death for the 40 million residents of California.