(CNN) A report from the international scientific authority on climate change warning consequences could be drastic if "rapid, far-reaching and unprecedented changes" are not made to mitigate global warming contrasts starkly with Trump administration policies decreasing federal regulation of greenhouse gas emissions.

To prevent global warming from passing 1.5 degrees Celsius, emissions would "need to decline rapidly across all of society's main sectors," such as industry, energy and agriculture, the report says. Global net emissions of carbon dioxide would need to fall by 45% from 2010 levels by 2030 and reach "net zero" around 2050 to keep the warming around that level.

Instead of bolstering policies that strictly limit greenhouse gas emissions, recent policy changes from the Trump administration relax those restrictions.

A few weeks later, the Environmental Protection Agency introduced the Affordable Clean Energy rule, which shifted the power to regulate coal power plants' carbon emissions from the federal government back to the states.

In September, the EPA released a proposal that would relax requirements for how energy companies monitor and repair methane leaks. The new proposal would require companies to conduct leak inspections at least once a year -- or every two years for low-producing oil and gas wells -- compared with every six months under the previous Obama-era rule. It also would give companies 60 days to repair leaks instead of 30.

When Congress passed the tax overhaul bill at the end of 2017, a provision in the legislation opened up Alaska's Arctic National Wildlife Refuge to oil and gas drilling. Congress had tried to pass the measure a number of times previously.

The UN panel's report names a number of ways countries can reduce emissions, including "phasing out coal in the energy sector, increasing the amount of energy produced from renewable sources" and "electrifying transport."

"We appreciate the hard work of the scientists and experts, many from the United States, who developed this report under considerable time pressure," EPA spokesman John Konkus said in a statement to CNN. "In accordance with IPCC procedures, the report and its contents remain the responsibility of its authors. Governments do not formally endorse specific findings presented by the authors."

Konkus noted that US greenhouse gas emissions have fallen by 12% since 2005.

Scientists working on the report said the world is already starting to see the impact of global warming by 1 degree Celsius and warned that if countries don't intervene to hold the warming at only 1.5 degrees Celsius -- instead of allowing it to reach 2 degrees Celsius -- some of the damage could be irreparable.

"Every extra bit of warming matters, especially since warming of 1.5 degrees Celsius or higher increases the risk associated with long-lasting or irreversible changes, such as the loss of some ecosystems," Hans-Otto Pörtner, a co-chair of the panel's Working Group II, one of the groups that compiled the report, said in a news release.

When asked what policies the EPA has implemented to reduce emissions, Konkus said that "every action EPA takes is directed to improve human health and the environment."