Changing Planet, Changing Health

By Bryan Walker 23/05/2011

Interconnectedness is a major theme of Changing Planet, Changing Health: How the Climate Crisis Threatens our Health and What We Can Do about It. Jeffrey Sachs describes the book in his preface as ’a scientific detective story of the first order, told with brilliance and relish by one of the world’s great ecological detectives’. The detective is physician and public health scientist Paul Epstein. He has co-authored the book with science writer Dan Ferber.

I warmed to the humanity of Epstein. He and his wife, a nurse, spent two years in newly independent Mozambique in 1978, part of a wave of cooperantes responding to the call for expert help from the government of a country deserted by its Portuguese professionals and destabilised by the South African apartheid regime’s funding of rightist guerrillas. It was there he experienced his first cholera epidemic and gained a new appreciation of the interwoven environmental and social determinants of health. And it was after that experience that he took up the study of public health at Harvard when he returned to Massachusetts. Throughout the book a decent human concern for the life conditions of poorer populations is evident. Human stories punctuate the narrative.

A later cholera epidemic in Peru in 1991, combined with the ground-breaking research of Rita Colwell pointing to the warm ocean as a source of cholera outbreaks, set Epstein on a new path of investigating the threats posed by global warming to human health. It’s rarely a simple connection as other factors are usually also involved, but he teases out the evidence convincingly. He describes, for instance, the painstaking work of Kenyan scientist Andrew Githenko in establishing that it was a warming temperature which enabled the spread of malaria-transmitting mosquitoes to the East African highlands previously free from them. His case had to be made in the face of strong and bitter opposition from medically well-credentialed deniers who blamed the malaria resurgence not on climate but on diminished efforts to kill mosquitoes and the malaria parasite’s growing resistance to drugs.

The book traces the threads which point to the increase of other diseases like Dengue fever, Rift Valley fever and Lyme disease as in part due to climate change. The narratives of the careful scientific work which underlies the attribution are fascinating reading, the conclusions modest and qualified. It seems highly likely that the climate change combination of warming and greater weather variability means millions face a higher risk of infectious disease.

A chapter on the air we breathe implicates the burning of fossil fuels as a factor in the occurrence of allergies, asthma, and other lung diseases. The confidence of an American senator recently in denying that carbon emissions and climate change are connected to asthma and sick children is not shared by the science Epstein explores. Not that that seems to bother many Republican politicians in their current fever of denial.

The book is not restricted to the effects of climate change on the occurrence of human diseases. It discusses, for example, the effects of raised CO2 levels on crops, among other things cautiously pointing to possible evidence that more CO2 and climate change may tip the plant-insect balance of power in favour of the insects. A plug for sustainable agriculture fits well at this stage of the book. The intricate connections of human health and welfare with the world’s seas and forests are highlighted as the effects of climate change on those vast ecosystems is explored. Some, such as the effects of lower fish takes on the diet of poorer populations, are immediately apparent.  Others, such as our dependence on biodiversity for our pharmaceutical treatments, are easily overlooked. Extreme weather events, especially in poorer parts of the globe, can result in clusters of epidemics on top of their immediate impacts.

The authors are up to date with climate science and fully aware that CO2 levels are going higher than they have been for millions of years. The whole Earth system as we have known it is heading for profound change. Taking a little Gaian licence they consider it fair to say that Earth has fallen ill. From our human point of view it certainly has, and there’s no arguing with the authors that we are in uncharted waters.

However the writers are interested in avoiding disaster and the last third of the book addresses that. Epstein has been involved with the insurance industry and has an interesting story to tell of the engagement of big reinsurers and other businesses with climate change issues, with encouraging evidence of at least some taking positive steps towards sustainability.  Solutions have to be treated with care. He looks at life cycle analyses of alternative energy sources, reporting one by a Stanford professor which came up with the following list in order of merit:  wind, concentrated solar, geothermal, tidal, solar photovoltaics, wave, hydroelectric, and then a last place tie between nuclear and coal with carbon capture and storage. The book notes that coal with CCS emits 60 to 110 times more carbon and air pollution than wind energy. Biofuels are only marginally better than nuclear. The policy favourites are nuclear, clean coal and biofuels, but Epstein regards them as duds, favoured only because of the powerful interests promoting them.

We need some basic changes if we’re to get past the dominance of vested interests. The rules of finance and trade must be rewritten. The rigid international free-market system which has held sway since the 1970s is driving poverty in the developing world. Currency speculation is wreaking havoc for many developing countries. Perverse subsidies are driving deforestation and supporting the production and consumption of fossil fuels. They must be dismantled. A large global environment and development fund, representing perhaps 1% of global GDP, needs to be established to enable poorer countries to protect biodiversity and tackle climate change.

The attention given to the global economic system is not an add-on to the health questions the book addresses. Early in the book Epstein describes himself as guided by systems theory, which means trying to see the whole, not just the component parts. He can’t look at the health problems climate change visits on a developing nation without also considering what the dominant economic order is doing to that nation. Honduras, for example, he describes as a poor country whose plight arises from many disasters, some natural, some the result of climate change, but some the result of global forces beyond their control. Mining, shrimp farming and monocrop agriculture extract resources from the country. Each sector is owned by wealthy foreign countries, each generates products for export, and in each case the profit is shared among a handful of politically connected Hondurans and the North American companies who own the projects.

The book argues for an acknowledgment of the seriousness of the threat to global health presented by climate change. It also argues for changes in the global economic system. To create a truly sustainable future we must accept limits. Boundless resources are not there for the taking. Heaven knows whether such sentiments are likely to prevail against current tides, but a book concerned with climate change and human health is surely right to voice them.

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