The World Bank said on Tuesday it was planning "aggressive action" to help developing nations cut emissions of soot and other air pollutants blamed for causing climate change, in a shift also meant to protect human health and aid crop growth.
Of its funding to poor nations, almost 8% - $18 billion from 2007-12 - goes to sectors such as energy, farming, waste and transport that have a potential to cut emissions, a bank report said.
The bank said it would shift policy to insist that such projects in future - it did not predict levels of funding - included a component to curb air pollution.
"We will try to turn it (the funding) into aggressive action" to cut the pollutants, Rachel Kyte, vice president of sustainable development at the World Bank, told Reuters on the sidelines of a meeting a 38-nation group in Oslo looking at ways to cut short-term air pollution.
"Anything that delays the pace at which global warming is arriving buys time for our clients, the poor countries in the world," Kyte said.
The bank would look for new ways to help, for instance, reduce pollution from public transport, curb methane emissions from rice irrigation, and improve the efficiency of high-polluting cooking stoves and brick kilns.
The focus on short-lived air pollutants is meant to complement efforts to cut carbon dioxide, the main greenhouse gas from human activities that a UN panel of climate scientists says is the main cause of global warming
Soot comes from sources ranging from wood-burning cooking stoves to diesel engines. Methane comes from decomposition of plant and animal matter and from farming, for instance from the digestive tracts of cattle and sheep.
Environment ministers at the meeting in Oslo of the Climate and Clean Air Coalition, set up 18 months ago in Washington as a new front in combating climate change, also outlined projects to cut air pollution in areas from forestry to gas flaring.
The focus on short-lived air pollutants is meant to complement efforts to cut carbon dioxide, the main greenhouse gas from human activities that a UN panel of climate scientists says is the main cause of global warming.
In a statement, members of the coalition said that cutting the short-term pollutants could reduce global warming by up to about 0.5 degree Celsius (0.9 Fahrenheit) by 2040-50.
That would help achieve a goal, set by almost 200 nations in 2010, of limiting a rise in global temperatures to below 2 degrees Celsius (3.6F) above pre-industrial times to avoid more heatwaves, floods, droughts and rising sea levels.
And cutting short-lived pollutants would also protect human health - six million people worldwide die early every year from air pollution, it said.