(CNN) The federal government is doing a worse job managing the problem of climate change under President Donald Trump, according to an investigation from the Government Accountability Office that included climate change on its High Risk List report on Wednesday.

This year's High Risk List is a 293-page assessment of the threats facing the federal government, including such matters as cybersecurity and problems at the Department of Veterans Affairs. The GAO has been putting the list together since 1990 and delivers it to Congress every two years to make legislators aware of the programs that it considers most vulnerable to mismanagement, fraud, waste or abuse and most in need of fixing.

Testifying Wednesday before the Senate Appropriations Homeland Security Subcommittee, GAO Comptroller General Eugene Louis Dodaro said that of the many areas that need improvement, "three areas have actually regressed," and limiting the federal government's fiscal exposure by better managing climate change risks is one of them.

Also in that category were the Environmental Protection Agency's process for assessing and controlling toxic chemicals and NASA acquisition management.

Because the government has revoked policies that had partially addressed climate change and has not taken steps recommended in previous reports, this high-risk area requires "significant attention," the new report says.

The government had been making big strides in improving its leadership on climate change in the Obama administration, according to past reports, but it "has not made measurable progress since 2017," the latest report says.

Climate change, in particular the severe storms it brings, has cost the American taxpayer nearly half a trillion dollars since 2015, the report says. "The last several years have been some of the most costly in US history," Dodaro said.

Mark Gaffigan, managing director of the GAO's natural resources and environment team, explained that there have been 241 billion-dollar events, an average of six a year, since 1980 . In recent years, there have been many more: an average of about 15 a year.

The government would be smart to spend money on the front-end to prepare for climate change, Dodaro said.

"For every dollar spent in hazard mitigation and resilience building saves $6 later," Dodaro said, citing research from the National Institute of Building Sciences . He said that if the United States were to adopt the most recent international building codes , which take climate change into account, it would save $11 for every dollar invested.

The Trump administration's response to flooding that will increase with climate change could also be a problem, he said.

"I'm also concerned that the administration revoked the flood hazard mitigation standard [that] required buildings to be elevated [and] have a national standard in that area," Dodaro said.

The federal flood insurance program is also on the High Risk List, he added. Even though Congress has forgiven $16 billion in debt to the Treasury, the program is still more than $20 billion in debt.

The report says the Trump administration increased the government's risk by rescinding guidance directing agencies to consider climate change in their reviews of certain federal projects.

Climate change also poses a serious threat to the country's 555,000 defense facilities, according to the report, especially those along the coasts. Asking what should be done about it, Sen. Gary Peters , D-Michigan, cited Tyndall Air Force Base in Panama City, Florida, which was unable to move a number of F-22 Raptors ahead of Hurricane Michael in 2018. Damage to the planes and the base cost $3 billion.

"They need to have a plan to look ahead as they are building their infrastructure, modernizing their infrastructure, to building resistance, climate resistance policies and procedures," Dadaro said, adding that Camp Lejeune in North Carolina had more than $3 billion worth of damage from Hurricane Florence last year.

The government should also create a national climate information system to help state, local and private-sector decision-making, the report said. Better climate change information could help local governments create better building codes, for example.

Weather satellite data is the one bright spot in the GAO's new report when it comes to climate change.

The previous report singled out aging satellites as a real problem. But now, the GAO determined that the National Oceanic and Atmospheric Administration and the Department of Defense followed its recommendations and created independent monitoring programs, and the departments showed that new satellites did not lead to data gaps.

The report probably would not come as a surprise to President Trump, who has repeatedly dismissed concerns about climate change .

In November , he dismissed a study produced by his own administration involving 13 federal agencies and more than 300 leading climate scientists, warning of the potentially catastrophic impact of climate change.

"I don't believe it," Trump said at the time, adding that he had read "some" of the report. Trump created a White House committee on climate change but put a climate change skeptic in charge.

The administration has proposed an end to several programs that fight climate change that were not mentioned in the report. In December, the EPA proposed relaxing regulations for newly built coal-fired power plants, a proposal that its own risk analysis determined would result in 1,400 more premature deaths a year as of 2030.

Also in December, the United States sided with Russia and Saudi Arabia to contest language supporting a landmark climate report on limiting greenhouse gas emissions.

The United States has reaffirmed its intention to withdraw from the landmark climate agreement called the Paris Accord, and polluters have seen the lowest level of EPA fines under this administration.

There has been a call for rapid action on climate change on Capitol Hill. Congress has held dozens of hearings to hear from experts who continue to warn that the government needs to act before it's too late.

The climate change report released in November said that the nation's economy could lose hundreds of billions of dollars -- or, in the worst-case scenario, more than 10% of its GDP -- by the end of the century and that it would kill thousands of people.

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Humans are already living with the warmest temperatures in modern history. Even if the best-case scenario were to happen and greenhouse gas emissions were to drop to nothing, the world is on track to warm 1.1 degrees Fahrenheit.

Without preparation for changes like this, "there is a lot of exposure that the federal government has," Dodaro said.