Pedestrians and cyclists should be made king of the urban jungle, according to an international study showing the big benefits of "mass active travel."
It suggests money should be diverted way from roads to make walking and cycling "the most direct, convenient, and pleasant options for most urban trips." Pedestrians and bikers should also get "priority" over cars and trucks at intersections.
The study is one of six reports on the "health dividend" of combating climate change published in the medical journal Lancet Wednesday.
The reports say that enormous changes are needed to slow global warming, but show that reducing carbon dioxide emissions will be good for people's health. Millions of deaths could be averted by getting people out of cars, breathing cleaner air and eating healthier food.
Public health researchers and leaders issued the reports in a bid to get the message across to world leaders and negotiators heading to next month's climate talks in Copenhagen.
"Sadly, policy-makers have been slow to recognize that the real bottom line of climate change is its risk to human health and quality of life," Dr. Margaret Chan, director general of the World Health Organization, says in a commentary with the studies.
She says the threats to public health are real: Climate change is expected to increase malnutrition, and its "devastating effects" on child health, worsen floods, droughts, storms and heat waves, and alter the geographical distribution of insects that spread malaria and dengue.
"The issue now is not whether climate change is occurring, but how we can respond most effectively," says Chan.
The up-side, say Chan and the researchers, is that some carbon-reduction strategies could result in major health improvements.
Simple measures to improve household energy efficiency could have huge benefits, according to one study that looked at polluting indoor cook stoves widely used in low-income countries.
Replacing the stoves with low-emissions stove technology that costs $50 US per household has the potential to "avert millions of premature deaths and hundreds of millions of tonnes of CO2-equivalent greenhouse pollutants," says the study led by Dr. Paul Wilkinson at the London School of Hygiene and Tropical Medicine.
It found a 10-year program to introduce 150 million efficient, low-emission cooking stoves in India could by 2020 prevent 240,000 children under age five from dying of acute lower respiratory infections and more than 1.8 million premature adult deaths from heart disease and chronic obstructive pulmonary disease.
Reducing the use of coal to produce electricity would also have "co-benefits," a second study reports. Carbon emissions wafting into the atmosphere would be reduced along with particulate air pollutants linked to lung cancer, and acute respiratory and cardio-respiratory illnesses. The researchers say that by 2030 "decarbonizing" electricity production could prevent an estimated 93,000 premature deaths in India, another 57,000 in China and 5,000 in the European Union.
The urban transportation study says encouraging more walking and cycling would have big benefits for both health and the climate. It compared different transportation scenarios for London and Delhi. Walking and cycling came out on top even when compared to increased use of low-emission vehicles that are widely touted as "green" solutions.
"Important health gains and reductions in CO2 emissions can be achieved through replacement of urban trips in private motor vehicles with active travel in high-income and middle-income countries," the researchers conclude.
They suggest policy-makers divert investment away from roads and toward provision of infrastructure for pedestrians and cyclists. They suggest motor vehicles be slowed down and more strictly controlled, while pedestrians and bikers should have direct routes with priority at intersections, to "increase in the safety, convenience, and comfort of walking and cycling."