Jonathan Patz et al have recently published a review paper on the Impact of Regional Climate Change on Human Health, in a special feature on regional climate change in the Nov 16th issue of Nature.

The article shows that climate change is already a substantial factor shortening people’s lives. The authors estimate that climate change kills an excess 154 000/yr. This mortality compares with 6 million deaths/yr caused by childhood and maternal malnutrition (the largest proportion of mortality) and with 109 000 deaths/yr from carnciogen exposure (data from Rodgers et al 2004 Distribution of Major Health Risks: Findings from the Global Burden of Disease Study. PLOS Medicine pdf)

Climate change deaths are estimated to occur primarily due to increases in malnutrition (77 000 deaths), diarrhoea (47 000 deaths), and Malaria (27 000 deaths). However, the health impacts of climate change vary greatly across the world. In general the areas, least responsible for changing the climate, are suffering the most deaths from climate change. These deaths are concentrated in poor countries, with about half of these deaths occuring in poor countries in S and SE Asia (specifically Bangladesh, Bhutan, Democratic People’s Republic of Korea, India, Maldives, Myanmar, Nepal), which are home to 1.2 billion people.

The mismatch between the countries most responsible for producing climate change and its impact is shown in the two maps below. The first map shows CO2 emissions/capita in 1998 from WRI data, while the second shows the estimated numbers of deaths per million people that could be attributed to global climate change in the year 2000 (From Patz et al). The mismatch be further exagerated if the cumulative CO2 emissions/capita of nations, a better indicator of national responsibility for climate change, were shown.

[click on a map to see a larger version]

On WorldChanging paper co-author, and resilience researcher, Jon Foley writes

Countries in the North (especially the U.S.) are some of the biggest CO2 polluters, but burden of disease resulting from climate change is likely to be felt by the world’s poorest people — mostly in the South.
Of course, we’ve been asked by some more skeptical folks why this should matter to people in the North (especially in the U.S.). After all, we export lots of environmental problems to the South already, so why is this any different? Why should we worry in the U.S.? Isn’t this another “feel guilty” story? What’s in it for us?

Well, in an age of global disease pathways (when a microbe can hop on an airplane and be *anywhere* in about 24 hours), global economic opportunities, and global terrorism, this may ultimately come back to bite us. Do we really want to exacerbate tensions between North and South, between rich and poor, and between those who pollute and those who die?

I’ll let others expand on this idea, but we’re touching upon a common theme discussed at WorldChanging: you can’t have real security without sustainability. A secure world will require a viable and healthy environment, with an improved sense of equity and environmental justice. And I think it’s in *all* of our interests, even taking an “enlightened” selfish view.

Further reading:

The Patz et al paper is discussed in an article on SciDev.net. and on the SAGE website at University of Wisconsin. It is also discussed in news articles in the Washington Post, and the Guardian.

The Nature special feature on regional climate change has a number of other interesting articles including a research article on Potential impacts of a warming climate on water availability in snow-dominated regions and commentaries on Dutch and US responses to climate change.

WHO’s report on Comparative Quantification of Health Risks, which provides a comprehensive assessment of the Global and Regional Burden of Disease Attribution to Selected Major Risk Factors. This assessment is huge and covers the impacts of wide range health factors ranging from malnutrition, to unsafe sex, to contaminated injections in health care. Along with mortality they estimate disability-adjusted life year (DALY) are more sensitive measure of human well-being. DALYs are a method of calculating a population level impact of a disease in terms of cases of premature death, disability and days of infirmity due to illness from a specific disease or condition. DALYs are the sum of years of life lost to the disease and years of life lived with disability (weighted by the severity of disability).