Eliminating the use of cook stoves, such as this one in Mongolia, for heating could help reduce greenhouse gas emissions and their health effects, researchers say. (Greg Baker/Associated Press)

Cutting emissions that cause global warming would not only make the planet healthier, it also would make people healthier too, new research suggests.

Slashing carbon dioxide emissions could save millions of lives, mostly by reducing preventable deaths from heart and lung diseases, according to studies released Wednesday and published in a special issue of the Lancet British medical journal.

'Here are ways you can attack major health problems at the same time as dealing with climate change.'— Dr. Paul Wilkinson

Global and U.S. health officials unveiled the results as they pushed for health issues to take a more prominent role at upcoming climate change negotiations in Copenhagen.

Also on Wednesday, President Barack Obama announced that he would go to Copenhagen at the start of international climate talks. U.S. health officials said the timing was not planned.

"Relying on fossil fuels leads to unhealthy lifestyles, increasing our chances for getting sick and in some cases takes years from our lives," U.S. Health and Human Services Secretary Kathleen Sebelius said in a telecast briefing from her home state of Kansas. "As greenhouse gas emissions go down, so do deaths from cardiovascular and respiratory diseases. This is not a small effect."

Sebelius, British health officials, United Nations Secretary General Ban Ki-moon and the head of the World Health Organization all took part in briefings based in Washington and London.

Immediate benefits in lives saved

The Lancet took an advocacy role in commissioning the studies and timing their release before the Copenhagen summit, but the science was not affected by the intent, said journal editor Dr. Richard Horton.

Instead of looking at the health ills caused by future global warming, as past studies have done, this research looks at the immediate benefits of doing something about the problem, said Linda Birnbaum, director of the U.S. National Institute of Environmental Health Sciences. That agency helped fund the studies along with the Wellcome Trust and several other international public health groups.

The calculations of lives saved were based on computer models that looked at pollution-caused illnesses in certain cities. The figures are also based on the world making dramatic changes in daily life that may at first seem too hard and costly to do, researchers conceded.

Some possible benefits seemed highly speculative, the researchers conceded, based on people driving less and walking and cycling more. Other proposals studied were more concrete and achievable, such as eliminating cook stoves that burn dung, charcoal and other polluting fuels in the developing world.

And cutting carbon dioxide emissions also makes the air cleaner, reducing lung damage for millions of people, doctors said.

"Here are ways you can attack major health problems at the same time as dealing with climate change," said lead author Dr. Paul Wilkinson, an environmental epidemiologist at the London School of Hygiene and Tropical Medicine.

The calculations are based on proposals that would cut global greenhouse gas emissions by 50 per cent by 2050. To accomplish that, industrialized countries have to cut emissions by 83 per cent. Obama's proposal, also unveiled Wednesday with his Copenhagen announcement, is in sync with that.

Low-polluting cars

Wilkinson said the individual studies came up with numbers of premature deaths prevented or extra years of life added for certain locales.

For example, switching to low-polluting cars in London and Delhi, India, would save 160 lost years of life in London and nearly 1,700 in Delhi for every million residents, one study found. But if people also drove less and walked or biked more, those extra saved years would soar to more than 7,300 years in London and 12,500 years in Delhi because of less heart disease.

Outside scientists praised the studies and said the research was sound.

"The science is really excellent; the modelling is quite good," said Dr. Paul Epstein of the Harvard School of Medicine's Center for Health and the Global Environment. "It really takes the whole field a step farther."