Major government climate change report contradicts Trump and warns of devastating economic and health impact

The US will face devastating economic and health impacts from climate change by the end of the century, a new federal report has warned.

National Climate Assessment outlines the projected impact of global warming in every corner of US society, in a dire warning that is at odds with Donald Trump and his administration’s pro-fossil-fuels agenda.

“With continued growth in emissions at historic rates, annual losses in some economic sectors are projected to reach hundreds of billions of dollars by the end of the century – more than the current gross domestic product (GDP) of many US states,” the report said.

The report, released nearly a month early by a team of 13 federal agencies, called the US Global Change Research Programme, said there is “no convincing alternative explanation” for climate change besides “human activities, especially emissions of greenhouse gases”.

The report runs counter to statements frequently made by Mr Trump, who has claimed global warming is a hoax. The president once again tweeted on Wednesday, “Whatever happened to Global Warming?” as temperatures were set to reach record lows on Thanksgiving.

Meanwhile, his administration released the report – the second of two volumes and the fourth National Climate Assessment in history – on Friday during the extended Thanksgiving holiday weekend, leaving some to question whether the aim was to minimise its public impact.

The White House dismissed the report as inaccurate, despite it supplementing a study issued last year that concluded humans are the main driver of global warming and warned of potentially catastrophic effects to the planet.

White House spokeswoman Lindsay Walters said the new report was “largely based on the most extreme scenario, which contradicts long-established trends by assuming that ... There would be limited technology and innovation, and a rapidly expanding population.”

Altogether, gross domestic product could be slashed by 10 per cent by 2100, losses twice the size of that which occurred during the Great Recession.

The poorest communities nationwide would be among the most disproportionately impacted by global warming, the report indicated, as droughts, flooding and increasingly powerful storms begin regularly plaguing the country.

“Future risks from climate change depend primarily on decisions made today,” the report said, making clear that projections could change, but only if greenhouse emissions are sharply curbed.

Mr Trump’s administration has been rolling back Obama-era environmental and climate protections to maximise production of domestic fossil fuels, including crude oil, already the highest in the world, above Saudi Arabia and Russia.

Experts told the New York Times the president’s political critics and climate activists could use the major report to battle Mr Trump’s environmental policies.

“This report will weaken the Trump administration’s legal case for undoing climate change regulations, and it strengthens the hands of those who go to court to fight them,” Michael Oppenheimer, a professor of geosciences and international affairs at Princeton, said.

The dire impacts of climate change could cost the US hundreds of billions of dollars annually, the report said, threatening agriculture production for corn and soybean farms, two major US industries.

The changing climate will also cost fishers nearly $230m by the end of the century as ocean acidification increasingly develops across the nation’s coastlines.

Global warming could greatly increase the spread of disease and increase mental health issues, as well as a sharp decrease in air quality across the country.

Water supplies and damage to infrastructure would be likely under even some of the best case examples, in which the temperature would still continue to rise.

In a statement, Brenda Ekwurzel, director of climate science at the Union of Concerned Scientists and one of the authors behind the report, stressed the need for the US government to respond to the report with action.

“This report makes it clear that climate change is not some problem in the distant future. It’s happening right now in every part of the country,” she said.

The fourth National Climate Assessment supported previous research conducted by government analysts, which also showed extreme adverse impacts on the economy and community health due to climate change.

Last year, Mr Trump announced the US was withdrawing from the 2015 Paris Climate Accord, claiming the environmental benefits did not outweigh the potential damage the agreement would have on the US economy.

Climate change is likely to increase all Americans’ exposure to food borne and waterborne diseases, as well as mosquito and tick-borne diseases like the Zika virus, dengue, and cases of West Nile, which could double in levels by 2050, according to the report.

The impact of increasing temperatures is also expected to cause a surge in the rate of premature deaths to 2,000 annually by 2090.

Meanwhile, none of the countries included in the G20 have met their climate targets, according to research, despite the US being among the only nations to withdraw its support from the Paris Accord.

The changing climate could pose enormous consequences when it comes to wildfire seasons – and may have already proven how dire those consequences can be.

California, which saw the deadliest and most destructive fire in history this month, could face blazes up to six times larger in size and scope by 2050, along with other regions across the US.

The report concludes “that the evidence of human-caused climate change is overwhelming and continues to strengthen, that the impacts of climate change are intensifying across the country, and that climate-related threats to Americans’ physical, social, and economic well-being are rising”.

It followed the Intergovernmental Panel on Climate Change’s latest report published in October, which indicated the world may have just a few decades left to prevent the depletion of virtually all coral reefs, and to keep temperatures from warming more than 2C, along with other detrimental consequences.