The Supreme Court on Monday nibbled away at President Barack Obama's authority to regulate greenhouse gas emissions but broadly upheld the effort to fight climate change.

Responding to a lawsuit by energy businesses, the top US court took issue with one root argument of the Obama administration -- that the Environmental Protection Agency has the power under the landmark Clean Air Act to restrict the greenhouse gases blamed for climate change.

But the Supreme Court agreed that the federal agency has the power to set pollution control standards on greenhouse gases much as the government does for other emissions.

Justice Antonin Scalia, speaking from the bench, said that the decision will allow the agency to regulate the stationary sources responsible for 83 percent of greenhouse gas emissions, with only three percent coming under question due to the ruling.

Writing a decision for the court's majority, Scalia rejected arguments that pollution control standards on greenhouse gases would be "disastrously unworkable."

"We are not talking about extending EPA jurisdiction over millions of previously unregulated entities, but about moderately increasing the demands EPA (or a state permitting authority) can make of entities already subject to its regulation," wrote Scalia, generally one of the most conservative justices.

The decision came after four months for deliberation and does not directly affect a major initiative announced by Obama earlier in June that aims to cut carbon emissions by power plants by 30 percent by 2030 from 2005 levels.

But it marks a victory for the administration which has been forced to rely on executive authority to battle climate change in the face of intense opposition in Congress by lawmakers supportive of coal and other fossil fuel industries.

The decision, however, challenged the Environmental Protection Agency's stance that it can regulate greenhouse gases as an "air pollutant" under the Clean Air Act, which was first approved in 1963 before widespread attention on climate change.

Scalia wrote that the executive branch was relying on ambiguous language and overstepping the authority of Congress to make laws.

"We are not willing to stand on the dock and wave goodbye as EPA embarks on this multiyear voyage of discovery," Scalia wrote.

In a dissent, Justice Stephen Breyer said he interpreted the Clean Air Act as giving the agency "nothing more than the authority to exempt sources from regulation" if they do not meet the intentions of Congress.

May global temperature hits all-time high
Washington (AFP) June 23, 2014 - Last month was so hot it set a new record for the planet, marking the warmest May over land and water since record-keeping began in 1880, US authorities said Monday.

The combined average temperature across the globe was 59.93F (15.54C), or 1.33F (0.74C) above the 20th century average, said the National Oceanic and Atmospheric Administration.

The previous record for May was set in 2010.

"The majority of the world experienced warmer-than-average monthly temperatures, with record warmth across eastern Kazakhstan, parts of Indonesia, and central and northwestern Australia," NOAA said.

The findings are part of an ongoing trend of rising global warmth.

Each and every May over the past 39 years has been hotter than the 20th century average, according to NOAA.

April was also historically hot across the globe, and tied with 2010 for the highest average temperature since 1880, NOAA said.

The last time global May temperatures fell below the 20th century average was in 1976, the agency said.