The last gasoline-powered car will have to be sold by about 2035 to put the world on track to limit global warming to the most stringent goal set by world leaders last year, a study said on Thursday.
The report, by a Climate Action Tracker (CAT) backed by three European research groups, said a drastic shift was needed towards clean electric cars and fuel efficiency since transport emits about 14 percent of world greenhouse gas emissions.
Last December, world leaders at a Paris summit set a goal of limiting a rise in temperatures to "well below" 2 degrees Celsius (3.6 Fahrenheit) above pre-industrial times while "pursuing efforts" for a much tougher 1.5 C (2.7F) ceiling.
"We calculate that the last gasoline/diesel car will have to be sold by roughly 2035," the CAT report said, to make the car fleet consistent with staying below 1.5C. It assumes the last fossil-fuel vehicles would be on the roads until 2050.
The CAT is one of the main groups that monitors government actions to restrict global warming and includes researchers who are authors on U.N. climate reports.
"It's striking that it's so early - it means a huge change in the whole automobile industry," Niklas Höhne, of the NewClimate Institute, told Reuters. The other think-tanks behind the report were Ecofys and Climate Analytics.
The phase-out is earlier than set by most car makers. Toyota, for instance, has a "zero carbon dioxide emissions challenge" for new vehicles under which it aims to cut emissions from its vehicles by 90 percent by 2050, from 2010 levels.
Many scientists reckon that the 1.5C goal, seen by many developing nations as a dangerous threshold for droughts, floods and rising sea levels, has already slipped out of reach and that the 2C limit is growing close.
They believe temperatures will almost inevitably overshoot 1.5C, and that new technologies will be needed to turn down the global thermostat later this century. This year is set to be the warmest on record, with temperatures around 1C (1.8F) above pre-industrial times.
The CAT report focused most on the promise of electric vehicles, developed by manufacturers from General Motors to Tesla. Other options are cars run on biofuels or hydrogen.
The study said a greener transport sector would require a parallel shift to clean power generation, to avoid charging electric cars on power based on fossil fuels.
"Electric vehicles are still more expensive to purchase than other cars, and policy projections still only see a share of around five percent of electric vehicles in the total European Union, China and U.S. fleets by 2030," the report said.