By Alister Doyle
MARRAKESH, Morocco (Reuters) - Donald Trump's election as U.S. president muddies the outlook for efforts to cut greenhouse gases and could mean U.S. emissions stay flat until 2030, compared with deep cuts planned by President Barack Obama, scientists said on Thursday.
Republican Trump, who has called climate change a hoax and is expected to favor the coal and oil industries, opposes last year's Paris Agreement by almost 200 nations to combat global warming.
In the past year "national climate policies have made little progress, and the road ahead looks even less clear after the results of the U.S. presidential elections," three European scientific groups said in a report of global trends.
"If President Trump abandons current policies as he has threatened to do, we estimate that in 2030, U.S. emissions will be similar to what they are today," said Niklas Hoehne, of NewClimate Institute, one of the research groups.
Obama promised in Paris to cut U.S. greenhouse gas emissions by between 26 and 28 percent by 2025 from 2005 levels. U.S. data show emissions were down 9 percent in 2014, compared to 2005.
A Climate Action Tracker compiled by the researchers, issued at U.N. talks on climate change in Marrakesh, projected that existing policies including Obama's would lead to a warming in global temperatures of 2.8 degrees Celsius (5.0 Fahrenheit) above pre-industrial times by 2100.
That is fractionally above a projected 2.7C (4.9F) rise in average surface temperatures estimated a year ago, largely due to technical revisions.
Current policies need to be ratcheted up to achieve a goal set in Paris of limiting global warming to "well below" 2C (3.6F) by curbing a build-up of man-made greenhouse gases blamed for causing downpours, heatwaves and rising seas, the scientists said.
It was too early to say how Trump's policies might affect the global outlook, they added. His election "would increase our (global) temperature estimate, but there are huge uncertainties," Hoehne said.
Still, the study said a shift to renewable energies was likely to continue thanks to factors such as falling prices of solar power and wind power and improved ranges for electric vehicles.
"Provided political leaders globally maintain their commitment to action, these tailwinds mean we should be able to ride through the turbulence that a climate skeptic in the White House could bring," said Bill Hare, CEO of Climate Analytics.
(Reporting by Alister Doyle; Editing by Mark Trevelyan)