The effects of climate change since 2000 will slow U.S. economic growth slightly over the next 30 years, adding another drag on an economy that will struggle to rebound from the coronavirus pandemic, the Congressional Budget Office (CBO) said on Monday.

In a new research paper, the nonpartisan budget referee agency studied both positive and negative contributions to gross domestic product (GDP), from longer growing seasons in colder climates to drought and damage to factories from more intense storms.

It projected that on net, climate change will reduce real U.S. GDP by an average of 0.03 percent annually from 2020 to 2050, compared to what U.S. growth would have been if global climate conditions remained the same as they were in 2000.

The reduction in growth rate, accumulated over 30 years, lowers the CBO's projected level of real GDP output in 2050 by 1 percent, the paper showed.

CBO researchers said that some aspects of climate change are incorporated quickly and directly, while others are more indirect and could take longer to manifest themselves.

For example, a hurricane that destroys factory equipment worth 50 million U.S. dollars would affect GDP in several ways, such as an immediate fall in production and spending on replacing the equipment damaged.

The overall capital stock would be smaller in the future as a result of foregone investments to pay for the replacement costs, leading to less GDP output in the future, the report added.

Addressing the UN General Assembly on Tuesday, Chinese President Xi Jinping said China would achieve a peak in carbon dioxide emissions before 2030 and carbon neutrality before 2060, as the country contributes in fighting against climate change.

This is in contrast with U.S. President Donald Trump rolling back or paring down hundreds of environmental regulations in his country. Trump has referred to climate change as a "hoax," and in 2017 pulled the U.S. out of the Paris climate accord which laid out an international approach to the problem. He claimed on Tuesday that the U.S. had reduced its carbon emissions by more than any country in the agreement.

(With input from Reuters)