GENEVA, Oct 31 (Reuters) - Greenhouse gas emissions are on course to be about 30 percent above the level needed to keep global warming to an internationally agreed target in 2030, the United Nations said on Tuesday.
"Without enhanced ambition the likely global average temperature increase will be in the range of 3.0-3.2 degrees Celsius by the end of the century," U.N. Environment said as it issued its annual audit of emissions reductions.
By 2030, annual emissions are likely to be 53.0-55.5 billion tonnes of carbon dioxide equivalent, far above the 42 billion tonne threshold for averting a temperature rise of more than 2 degrees Celsius (3.6 degrees Fahrenheit) this century, the U.N. environment agency said.
The latest projection, which assumes all countries meet their commitments, is slightly lower than the gap of 12-14 billion tonnes foreseen a year ago, reflecting new data on national emission reduction programmes.
The report said there was increasing evidence that carbon dioxide emissions from fossil fuels, cement production and other industrial processes remained stable for the past three years, largely due to slower growth in coal use in China and the United States. But the trend could be reversed, and 80-90 percent of coal reserves must remain in the ground, it said.
In 2015, 195 countries signed the Paris climate accord, pledging to limit global warming to "well below" 2 degrees Celsius above pre-industrial times. Ministers will meet in Bonn next month to work on guidelines for the agreement.
A harder target of keeping warming to within 1.5 degrees would mean a further reduction of about 5 billion tonnes of emissions.
The U.N. said on Monday that the amount of carbon dioxide in the atmosphere grew at record rate in 2016 to a level not seen for millions of years, potentially fuelling a 20-metre (65-foot) rise in sea levels and adding 3 degrees Celsius to temperatures.
The Paris agreement is already under pressure because U.S. President Donald Trump has said he plans to pull the United States out of the deal unless there is a renegotiation more favourable to Washington. (Reporting by Tom Miles; Editing by Robin Pomeroy)