Which Climate Threats Are Most Worrisome? U.S. Agencies Made a List.

WASHINGTON — Less food. More traffic accidents. Extreme weather hitting nuclear waste sites. Migrants rushing toward the United States, fleeing even worse calamity in their own countries.

Those scenarios, once the stuff of dystopian fiction, are now driving American policymaking. Under orders from President Biden, top officials at every government agency have spent months considering the top climate threats their agencies face, and how to cope with them.

On Thursday, the White House offered a first look at the results, releasing the climate-adaptation plans of 23 agencies, including the departments of Energy, Defense, Agriculture, Homeland Security, Transportation and Commerce. The plans reveal the dangers posed by a warming planet to every aspect of American life, and the difficulty of coping with those threats.

The federal government has attempted this exercise before, during the Obama administration. That work effectively stopped under former President Donald J. Trump, whose disdain for climate science led most agencies to either shelve their planning for climate change or stop talking about it.

Within weeks of taking office, President Biden directed officials to quickly resume the work. Stressing the urgency of the threat, the president gave agencies four months to come up with plans that listed their main vulnerabilities to climate change and strategies to address them.

“Nearly every service that the government provides will be impacted by climate change sooner or later,” said Jesse Keenan, a professor at Tulane University who focuses on climate adaptation and has advised federal agencies.

The plans released Thursday are brief, many of them fewer than 30 pages. They include core themes: ensuring that new facilities meet tougher construction standards, using less energy and water at existing buildings, better protecting workers against extreme heat, educating staff about climate science, and creating supply chains that are less likely to be disrupted by storms or other shocks.

The documents also reflect Mr. Biden’s emphasis on racial equity, looking at the effects of climate change on minority and low-income communities and how agencies can address them. For example, the Department of Health and Human Services said it will focus research grants on the health effects on those communities.

But the most revealing information in the newly released plans could be their description, sometimes in frank terms, of the dangers that climate change holds.

Agriculture

The Department of Agriculture lists the ways climate change threatens America’s food supply: Changes in temperature and precipitation patterns, more pests and disease, reduced soil quality, fewer pollinating insects and more storms and wildfires will combine to reduce crops and livestock.

To address those challenges, the department calls for more research into climate threats, and better communication of those findings to farmers.

The plan is also candid about the limits of what can be done. In response to drought, for example, farmers can build new irrigation systems, and governments can build new dams. But irrigation is expensive, the department notes, and dams affect the ecosystems around them.

Transportation

Climate change also threatens Americans’ ability to move within and between cities, restricting not just mobility but the transportation of goods that drive the economy. In a list of potential effects from climate change, the Department of Transportation notes that rising temperatures will make it more expensive to build and maintain roads and bridges.

And the experience of getting around will become slower and more frustrating. As hotter days cause asphalt to degrade, congestion will increase as traffic slows. Severe weather events will “require flight cancellations, sometimes for extended periods of time,” and more heat will force planes to fly shorter distances and carry less weight.

Some of the effects the transportation department anticipates are dangerous. They include “more frequent/severe flooding of underground tunnels” and “increased risk of vehicle crashes in severe weather.”

Even the quality of driving could get worse. The plan warns of “decreased driver/operator performance and decision-making skills, due to driver fatigue as a result of adverse weather.”

Energy

Sometimes, the plans demonstrate how much work remains. The Department of Energy, for example, said it has assessed the climate risks for just half of its sites, which range from advanced research laboratories to storage facilities for radioactive waste from the nuclear weapons program.

“DOE’s nuclear security mission is critical to national security and is also largely conducted at DOE sites that are vulnerable to extreme weather conditions,” the department’s plan says. “DOE’s environmental mission could also experience disruptions if facilities dedicated to radioactive waste processing and disposal are impacted by climate hazards.”

The department says it’s able to address that threat, but doesn’t go into specifics. “DOE has a well-established hazard assessment and adaptation process focused on its high-hazard nuclear facilities. This process ensures that the most critical facilities are well protected from climate risks,” the plan states.

Homeland Security

For the Department of Homeland Security, climate change means the risk of large numbers of climate refugees — people reaching the U.S. border, pushed out of their countries by a mix of long-term challenges like drought or sudden shocks like a tsunami.

“Climate change is likely to increase population movements from Mexico, Central America, South America, and the Caribbean,” the department’s plan reads. The department is trying to develop “a responsive and coordinated operational plan for mass migration events,” it said.

The plan comes just weeks after President Biden condemned Border Patrol officers on horseback for their treatment of Haitian migrants crossing the border into Texas. The administration then faced criticism for sending many of those migrants back to Haiti, which is still struggling from just the sort of environmental challenges described in the plan.

The department doesn’t say how it plans to respond in the future as more people flee to the United States, beyond saying it “will focus on national security and balanced, equitable outcomes.”

Defense

Climate change will lead to new sources of conflict, and also make it harder for the military to operate, the Department of Defense wrote in its climate plan.

Water shortages could even become a new source of tension between the U.S. military overseas and the countries where troops are based. At DOD sites outside the United States, “military water requirements might compete with local water needs, creating potential areas of friction or even conflict.”

But learning to operate during extreme weather should also be viewed as a new type of weapon, the plan says, one that can help the United States prevail over enemies. “This enables U.S. forces to gain distinct advantages over potential adversaries,” the plan reads, “if our forces can operate in conditions where others must take shelter or go to ground.”

Commerce

Not all of the climate threats facing the federal government are insurmountable.

The Department of Commerce, which runs the U.S. Patent and Trade Office, said that as the effects of climate change become more severe, it expects a surge in applications for patents for “climate change adaptation-related technologies.” Such a surge “would impact the department’s ability to process such applications in a timely manner, having a direct impact on U.S. competitiveness and economic growth.”

For that challenge, at least, there is a solution. For inventions that promise to help with environmental challenges, the department said, patent applications may be able to jump ahead in line — or, as the plan phrased it, “advanced out of turn for examination when a petition is filed.”