With time running out to head off the worst damage from climate change, the United States government is starting to quantify the cost of inaction – for taxpayers.

The White House Office of Management and Budget (OMB) released the first ever accounting of how unchecked global warming would impact the federal budget, looking at its potential to dampen the economy as a whole, and balloon the costs of climate-related programs over time.

"The fiscal risk of climate change is immense," wrote Candace Vahlsing, Associate Director for Climate, Energy, Environment, and Science at OMB, and Danny Yagan, Chief Economist at OMB, in a blog post discussing the analysis.

Key takeaways:

• The economy could shrink. A lot. Based on current warming trends, OMB predicted climate change could reduce the country's Gross Domestic Product, or economic output, by as much as 10% by the end of this century. That translates into an annual revenue loss to the federal budget of 7.1%, or about $2 trillion in today's dollars. For perspective, the Biden Administration's entire proposed budget for fiscal year 2023 is $5.8 trillion.

• Costs for key programs would rise. Major storms, floods, wildfires and other extreme weather events already cause around $120 billion a year in damages in the U.S., according to OMB. Some of that cost is borne by the government, in the form of insurance programs and post-disaster aid. With unabated climate change, the costs of six types of federal, disaster-related programs could rise anywhere from $25 billion to $128 billion by the end of the century. Hurricane damage is the biggest driver, accounting for as much as $94 billion in annual coastal disaster response cost increases by 2100.

• Some impacts are too vague to quantify. Climate risks to national security, changes to ecosystems, and infrastructure expenditures do not have a price tag attached to them yet. This also does not count the strain on other kinds of institutions. Looking beyond the federal government, the cost to public health and businesses "will be larger than the impact on our fiscal balance sheet," wrote the report's authors.

OMB plans to calculate and release these estimates annually, as directed by President Biden in an executive order. The analysis, while new, credits prior work by the National Oceanic and Atmospheric Administration (NOAA) and the Congressional Budget Office.

"It's kickstarting the government doing this," said Margaret Walls, Director of the Climate Risks and Impacts Program at Resources for the Future, a Washington research group. But, she continued, "it's imperfect."

Walls said she would like to see the government include the climate costs of safety net programs, such as unemployment insurance, in future versions.

Other groups are tracking the financial benefits of tackling climate change. Keeping warming within 2 degrees Celsius (3.6 degrees Fahrenheit) would generate more economic benefit globally than the cost of achieving that goal, according to the most recent report from the United Nations Intergovernmental Panel on Climate Change.

All of these efforts attempt to put a price tag on doing nothing.

"I think it will draw a lot more attention to the tradeoffs that come from acting on or ignoring climate change," said Jeremy Symons, project manager of the Climate 21 Project, which brought together more than 150 experts to create a blueprint for how President Biden can tackle climate change. He said the OMB analysis was heartening, because it showed that even modest emissions reductions could lead to much smaller spending increases for programs like wildland fire suppression and coastal disasters.

After failing to get climate change legislation passed as a part of Build Back Better, the Biden administration is now asking for $44.9 billion in the fiscal year 2023 federal budget, towards its climate goals. That includes $15 billion for clean energy investment and infrastructure, and another $18 billion for climate resilience.

Since Congress controls the federal purse strings, that budget is simply a proposal.