Climate change and disease - the issue is wealth not warming

Are we entering a new era, where a warmer climate brings pestilence, death and disease? Delegates, scientists and activists descended on New Delhi recently for the eighth United Nations climate change meeting, and they will likely devote much energy to solving this alleged problem. In particular, global warming campaigners claim that climate change is increasing the incidence of diseases such as malaria, particularly in poor nations.

This worry is probably a scare tactic to make wealthy nations sign onto policies that will not change the earth’s climate, whether or not it is warming. More importantly, these policies create misguided priorities for policymakers, who should be doing more to control disease and create wealth in their countries, rather than blaming disease on climate change. .

A simple internet search using the words ‘malaria’ and ‘climate change’ brings up hundreds of results, from scientific papers to general commentaries. Like many climate scientists, malaria scientists have latched onto the idea of climate change causing the spread of malaria as a good way to raise funds. Nothing gets donors to open their wallets like potential catastrophe of climate change!

While some of this research has been interesting, it is of little value to malarial countries and misses the most fundamental point: that man affects malaria far more than climate. Though malaria is now associated mostly with hot tropical countries, it used to be widespread throughout Europe and North America. These countries managed to eradicate the disease by using DDT shortly after the end of the Second World War, but malaria cases were actually declining since the end of the 19th century.

As with most other infectious diseases, malaria began to decline in Europe when people started to get rich, and could afford better housing, food and medicines. Increased agricultural development meant that mosquito breeding grounds were dried up. With mechanisation, fewer people were required for agricultural production, thereby separating the Anopheles mosquito from the human reservoir of parasites.

Western Europe witnessed a gradual decline in the incidence of malaria even before it was known that mosquitoes transmitted the disease. Yet as Dr. Paul Reiter points out in a paper published in the journal Environmental Health Perspectives, Poland and parts of Russia continued to be devastated by severe outbreaks of malaria well into the 1930s. This was due to a lack of economic development and inadequate measures to control mosquitoes and provide effective treatment.

It would seem fairly obvious that increased temperatures along with higher rainfall, as predicted by some climate scientists, would provide more mosquito breeding pools and worsen the incidence of malaria. Yet this view is too simplistic: the spread of malaria is dependant on many factors, and climate is only one of those. In some cases, increased rainfall can flush out mosquito breeding pools, thereby reducing the incidence of malaria. Reiter explains that Sri Lanka suffered one of its most devastating malaria epidemics during the 1930s in years when the monsoon failed. This was because the lower rainfall provided smaller puddles favoured for breeding by the major malaria vector. Higher rainfall would actually have lowered the incidence of malaria.

The highly simplistic link between climate and malaria has been criticised by Simon Hay in a recent study published in Nature on the link between climate change and malaria in East Africa. Hay examined long term meteorological trends and the incidence of malaria, and found little or no relationship between the recent increase in malaria cases in the East African Highlands, and climatic factors.

However, a lack of mosquito control with effective insecticides, an increase in drug resistance and population movements have been the factors behind the increase in malaria in East Africa. In South Africa, a recent severe malaria epidemic coincided with increased rainfall in the Kwa-Zulu Natal province, as well as drug resistance. Perhaps most importantly, the province abandoned the use of the insecticide DDT, which is used to kill the Anopheles mosquito. The reintroduction of DDT in 2000, along with new drug therapies, was followed by an 80% reduction in the number of malaria cases in 2001.

The South African Department of Health recognises that the epidemic was both primarily caused and controlled by human intervention -- or lack thereof. Even though rainfall fell slightly in 2001, climatic factors played a highly insignificant role in malaria control.

If countries like India want to control diseases such as malaria, they need to concentrate on becoming wealthy and on enabling people to control disease. With increased incomes, people can afford better personal protection and effective drugs, and can better control the breeding pools of the deadly Anopheles mosquitoes.

Sadly, the proposals made by the climate change campaigners will only make India poorer. They recommend that India reduce its reliance on fossil fuels and use more ‘renewable’ energy. This will surely make Indian industry less competitive, and the majority of Indian people will continue to have erratic, expensive energy, or they will go without it altogether. Even ‘dirty’ coal-fired electricity plants would improve wealth – and health – in India.

In addition, costly emission controls mandated by the Kyoto Protocol will slow growth and reduce spending in India’s, South Africa’s and other developing countries’ export markets – Europe and North America. These policies may be in vain also as many scientists agree that emissions controls are unlikely to have any discernable impact on the earth’s future climate.

It may be expedient for politicians blame wealthy countries for changing the climate, but it is unacceptable to blame disease on climate change. Delegates to the COP-8 meeting in Delhi would have done well to recognise that diseases such as malaria are symptoms not of climate change, but of poverty. The solution to this is to speed up economic growth and development in countries like India, so that their citizens can escape from age-old, deadly diseases such as malaria.

Author: Richard Tren is a director of the South African health NGO, Africa Fighting Malaria and was in Delhi for the UN Climate Change meeting. This article may be reproduced without prior consent but with acknowledgement to the author. The patrons, council and members of the Foundation do not necessarily agree with the views expressed by the author.

FMF Article of the Week/22 January 2003