For two years, President Barack Obama has used his executive power to impose new rules to cut carbon emissions, targeting cars and power plants, buoying environmentalists and infuriating industry.
His latest foray - regulating commercial aviation - had the opposite effect.
On Wednesday, the administration took a first step toward cutting greenhouse gas emissions from the nation's fleet of aircraft, releasing a scientific finding that said emissions from plane engines pose a risk to human health because they contribute to climate change.
But the Environmental Protection Agency (EPA) did not immediately propose new regulations. Instead, it signaled it would implement a global emissions standard being developed by the United Nations' International Civil Aviation Organisation (ICAO) that is due to be released next year.
Those rules are expected to apply only to new aircraft designs beginning in 2020, leaving most of the world's existing fleets unaffected for years to come.
That decision was greeted with cautious optimism from the aviation industry, which says it is making strides on energy efficiency and wants the United States to coordinate any new regulations with the rest of the world.
That was precisely what worried environmentalists, who warned that relying on a global agreement forged under UN auspices seeking consensus would be doomed to produce weak rules.
"The EPA is declaring aircraft greenhouse gases to be dangerous to all of us, but is passing the buck on doing anything about it," said Vera Pardee, an attorney for the Center for Biological Diversity that was among several green groups pushing the administration for years to adopt new regulations.
Indeed, the EPA was prodded to act on aviation only after a long legal fight.
A collection of environmental groups petitioned the agency to bring in new aviation regulations in 2007 and sued it to do so in 2010, winning a federal court ruling two years later that ordered the US government to regulate aircraft emissions under the Clean Air Act.
On Wednesday, the EPA acknowledged "certain classes of airplane engines contribute to air pollution that causes climate change endangering public health and welfare," and promised to follow ICAO's lead on new rules.
Airline companies were broadly supportive of the administration's approach.
The industry favors a global standard over national standards because carriers operate all over the world and want to avoid a patchwork of rules and measures, from taxes to emissions trading programs.
"We feel this is the right thing for the EPA to be doing, as a precursor to be able to adopt what comes out of ICAO," said Paul Steele, senior vice president at the International Air Transport Association.
"If you're a big airline and you're flying to 100 countries a day, then complying with all those different regimes is an administrative nightmare."
Controlling aviation emissions is seen by climate scientists as a vital cog in the wider attempt to curb global warming.
Commercial aviation accounted for three per cent of overall US emissions and 11 per cent from the US transportation sector in 2013, the EPA said.
The US industry was responsible for nearly 30 per cent of global aircraft emissions in 2010, the latest year with complete global emissions data.
Environmental groups cite studies indicating unregulated aviation emissions could triple by 2050, and they have been critical of the ICAO negotiations, saying the organisation's targets are not ambitious.
Sarah Burt, an attorney with Earthjustice, another organisation that sued the EPA, said ICAO is poised to set a"business-as-usual" standard that will lock in emissions increases for decades to come.
"The ICAO standard won't deliver substantial reductions because they are setting a standard that 90-95 per cent of aircraft already meet," she said, adding that planes tend to stay in service for 20 to 30 years.
The burden for meeting those lower emissions standards will fall to aircraft and engine manufacturers such as Boeing Co , Airbus Group SE, Pratt & Whitney and Rolls Royce but some experts want the new standards to apply to any plane delivered to carriers after 2020, rather than simply for newly designed aircraft.
"Applying the standard to all new aircraft delivered after 2020 is key," said Dan Rutherford, director of the International Council on Clean Transportation Program. "If ICAO grandfathers in existing designs, the standard would cover only about 5 per cent of the global fleet by 2030."
An EPA spokesman defended the decision to work through ICAO, arguing that an international standard would cover more planes than a simple domestic one.
But some critics want the White House to seek more aggressive targets than what is achievable under the consensus-driven international organisation. "If the Obama administration wants this to stand up next to its much more ambitious cars and power plants rule, it will need to do much more than follow the weak lead of ICAO," said Burt of Earthjustice.
Guyana to urge UN chief to settle Venezuela border row -world GEORGETOWN, Guyana, June 10, 2015 (AFP) - Less than a month after Venezuela unilaterally redrew its maritime boundary, neighbouring Guyana announced Wednesday it will ask the United Nations to legally settle Latin America's biggest territorial dispute.
Foreign Affairs Minister Carl Greenidge told AFP that Guyana would call directly on UN Secretary General Ban Ki-Moon to invoke provisions of the Geneva Agreement for a legally binding settlement.
Venezuela has long claimed Guyana's Essequibo region, which comprises two-thirds of Guyana's 215,000 square kilometers (83,000 square miles).
Guyana, a former British colony, maintains that the two countries' land boundary was settled in 1899 by a court of arbitration set up after a crisis that prompted the United States to intervene in favour of Venezuela against Britain, asserting the Monroe Doctrine.
Venezuela has never recognised the line, and the dispute has simmered ever since, extending in recent years to maritime rights off the disputed area.
In fact, Venezuela claims the territory stretching from its eastern frontier all the way to the Essequibo River, and the maritime rights off that area.
If Caracas prevails, it would end up taking over more than one half of mineral-rich and sparsely populated Guyana's entire territory.
Venezuela issued what Greenidge called a "baseless and shameless" decree on May 26, claiming maritime rights precisely where Guyana already gave American oil-giant ExxonMobil a prospecting contract.
Greenidge said Guyana now had little option but to find a lasting settlement to a controversy that has seen Venezuela block Guyana's attempt to explore for oil offshore and onshore, mine gold and build hydro-power stations.
In an address to parliament after recent polls, President David Granger promised his administration would "do everything within its power to secure our borders."
As of Wednesday, ExxonMobil's exploration oil rig, Deepwater Champion, continues to work on the concession located about 120 miles offshore Guyana.
ExxonMobil recently said it had found a "significant" reserve of high quality crude oil.