* World heading for warming over 3 degrees by 2100
* Current pledges far from halving emissions by 2050
By Nina Chestney
LONDON, Dec 3 (Reuters) - Global greenhouse gas emissions will nearly double from 1990 levels by 2040 based on current emissions reductions pledges, climate consultancy firm Ecofys said on Thursday.
In a new assessment of countries’ emissions cut commitments ahead of a U.N. climate summit next week, Ecofys said the world is headed for global warming of well over three degrees centigrade by 2100.
"The pledges on the table will not halt emissions growth before 2040, let alone by 2015 as indicated by the (U.N.’s) IPCC and are far from halving emissions by 2050, as has been called for by the G8," said Niklas Hohne, director of energy and climate policy at Ecofys.
Instead, emissions will nearly double 1990 levels by 2040.
China, India, Brazil and South Africa oppose setting a goal of halving world greenhouse gas emissions by 2050 and limiting global warming to a maximum of 2 degrees centigrade (3.6 Fahrenheit) above pre-industrial times, European diplomats said on Wednesday. [ID:nGEE5B127Q]
Ecofys said with Russian and U.S. pledges, developed country emissions are projected to be 13-19 percent below 1990 levels by 2020. But the use of forestry credits would reduce this range by 5 percent.
Russia offered to tighten curbs from 1990 levels to between 22 and 25 percent by 2020 in November while the United States pledged a cut roughly 17 percent below 2005 levels by 2020, a drop of about 3 percent below the 1990 benchmark year used in U.N. treaties. [ID:nSP483987]
In 2007, the U.N.’s Intergovernmental Panel on Climate Change (IPCC) called for a 25-40 percent reduction by 2020.
Recent Chinese carbon intensity goals and Korean emissions targets are "important and useful", but their overall effect on global emissions is disappointing, the report said.
"With no concrete pledges on the table for international aviation and marine carbon dioxide emissions, these are projected to grow to over double 1990 levels in 2020 (...) and to nearly four times 1990 levels in 2050," Hohne said.
"From these numbers there is at least a one in four chance of exceeding warming of four degrees."
Ecofys, Climate Analytics and the Potsdam Institute for Climate Impact Research have developed what they call the "Climate Action Tracker", which provides a picture of each country’s proposed commitments and actions.
The tracker reveals that Norway, Japan and Brazil are the developed nations with the most ambitious cuts. If the European Union commits to a 30 percent reduction by 2020 from 1990 levels, it would be considered a "sufficient" effort. The United States is between the middle and bottom of the scale.
(Reporting by Nina Chestney; Editing by William Hardy) ((email@example.com; +44 207 542 8071; Reuters Messaging: firstname.lastname@example.org))