Steps to combat climate change would also improve human health, commission says.

Climate change provides an opportunity to make big improvements in human health, because the changes needed to counter it will clean the air, encourage more active lives, rebuild cities in a more humane way, and improve the diet of those who live in them, a new report concludes. If nothing is done, says the Lancet’s Commission on Climate Change (thelancet.com/commissions/climate-change), the threat to human health is huge, with increasing frequency of direct effects such as heatwaves, floods, droughts, and storms and indirect effects that include changes in the pattern of disease, insecure food supplies, involuntary migration, displacement, and conflicts. Taken together, these effects have the capacity to undo the gains of the past 50 years in development and human health. But if the right steps are taken they will have many benefits beyond that of preventing the rise of global temperatures, the commission’s co-chair, Anthony Costello, told a press briefing at the Science Media Centre in London on 22 June. “The effects of a 4°C rise in global temperatures are very serious and potentially catastrophic,” he said. “It is a medical emergency that requires action now. But if we can fix it, it’s a great health opportunity. All the things we want to do to protect against climate change will help our health and save a lot of money. Combating climate change in fact represents one of the greatest opportunities to benefit human health for generations to come.” Costello, director of the Institute for Global Health at University College London, said that the measures needed to avert such a rise in temperature were known. “It’s not a technical question but a political one,” he said. Among changes the commission calls for are international agreement on a carbon pricing mechanism to drive an overall reduction in carbon emissions, which would result in health gains such as reducing pollution related respiratory disease, encouraging active transport (walking or cycling), and reducing obesity, diabetes, coronary heart disease, and stroke. Carbon pricing could be achieved through carbon taxes or emissions trading systems, both of which increase the price of generating carbon dioxide. The cash from carbon taxes should be retained by the countries in which it is raised but need not greatly increase the total tax burden, as it could be balanced by lowering other taxes, such as value added tax. Major carbon generators such as airlines might be forced to increase prices but not enough to prevent people travelling, said Paul Ekins, professor of resources and environmental policy at United College London and a member of the commission. “The most rapid growth is in short term, short segment travel—the stag parties in Barcelona kind of thing,” he said. “We might see less of that, but families would still be able to afford to take holidays abroad.” Hugh Montgomery, a consultant intensivist at Whittington Hospital in north London and another commission member, said that the health sector had to do its share. “The biggest win would not be having to treat people with diseases caused by lifestyle,” he said, estimating that eight in 10 patients in intensive care units had conditions that were “entirely preventable” and that would become much less common if lifestyle and diet became healthier as a result of changes designed to mitigate climate change. One simple measure, he said, was for dry powder inhalers to be prescribed for patients with asthma, eliminating the need for aerosol propellants, which are potent global warming gases. “The manufacturers would love it,” he said, “but it needs a little bit of a push, as dry powder inhalers are slightly more expensive.” Among health disasters that would occur if nothing were done, heatwaves rank higher than floods or droughts, the report says. It cites a heatwave that hit Russia in 2010, causing widespread forest fires and engulfing Moscow in plumes of smoke and ash that claimed 11 000 lives and damaged crops sufficiently to have a global effect on food prices. A rise of 4°C in global temperatures would triple the frequency of heatwaves, predicted GeorginaMace, also fromUniversity College London, and they would occur in areas expected to see big rises in population, multiplying their effects. The co-chair of the commission, Peng Gong, from Tsinghua University, Beijing, China, said, “The health community has responded to many grave threats to health in the past. It took on entrenched interests such as the tobacco industry, and led the fight against HIV and AIDS. Now is the time for us to lead the way in responding to another great threat to human and environmental health of our generation.” Jane Dacre, president of the Royal College of Physicians, welcomed the report. “Doctors have always taken a wider view of health than simply treating the individual patient in front of them,” she said, “and this report continues that tradition, showing that for a public health issue like climate change