There are simple and inexpensive measures to cut back on soot and methane that once employed could save millions of lives and slow climate change for years to come, according to an international team of scientists.

Rather than focusing on carbon dioxide emissions, there should be a shift to cutting two other pollutants, soot and methane according to the latest study from experts from North America, Europe, Africa, Asia and the Middle East. The study, called "Simultaneously Mitigating Near-Term Climate Change and Improving Human Health and Food Security" expands on a previous report from the United Nations Environmental Programme and the World Meteorological Organization.

Reducing soot and methane could lower worldwide global warming by one degree Fahrenheit within 40 years or so and it could cut air pollution deaths and increase crop yields. It would also be easier to focus on soot and methane rather than on carbon dioxide especially in the face of much resistance from countries who rely cheap fuel.

"Ultimately, we have to deal with CO2, but in the short term, dealing with these pollutants is more do-able, and it brings fast benefits," said lead author Drew Shindell researcher at the NASA Goddard Institute for Space Studies (GISS) and Columbia University's Earth Institute. "We have identified practical steps we can take with existing technologies. Protecting public health and food supplies may take precedence over avoiding climate change in most countries, but knowing that these measures also mitigate climate change may help motivate policies to put them into practice."

Methane is the flammable part of natural gas and is a more potent greenhouse gas than carbon dioxide. Soot is the byproduct of burning wood, dung, coal and other fuels. It causes heart and lung problems and warms the air and land.

The report lists some quick and easy ways to reduce methane and soot emissions. From the 400 ways that could control pollution, the study narrowed it down to 14 methods that would have the quickest effects. Some of the ways that could reduce methane are by capturing the gas that escapes from coal mines, cutting leaks from pipelines, reducing landfill emissions, modernizing water treatment plants, frequently draining rice paddies and lessening emissions from farm manure.

To reduce soot, the study suggests that additional filters should be installed on diesel vehicles, old home cookers should be replaced with clean-burning models, more efficient brick kilns, boilers and coke ovens should be built and burning farmlands in the tropics should be avoided.

"They're all things we know how to do and have done; we just haven't done them worldwide," said Shindell who acknowledged that it would be hard to implement the changes globally. Although the benefits would be far outweigh the costs, getting governments to agree to implement the changes could be a challenge.

"The scientific case for fast action on these so-called 'short-lived climate forcers' has been steadily built over more than a decade, and this study provides further focused and compelling analysis of the likely benefits at the national and regional level," said Achim Steiner, executive director of the Nairobi-based United Nations Environment Program.

The results of the study is published in the journal, Science.