Climate Change: Increasing The Spread of Diseases?

Melting ice caps, rising sea levels and extreme weather patterns aren't the only potential consequences of climate change. Scientists are warning that changes in global climate may also endanger public health by increasing the spread of diseases and other health problems.

The issue of climate change's impact on health is currently a popular one. World health experts have committed to research this area, and the topic has been the theme of medical journals and World Health Day this year. Researchers fear that current warming trends, if uncontrolled, will greatly increase health risks. These health hazards range from deaths related to extreme high temperatures and natural disasters to a change in patterns of diseases that are sensitive to temperature and precipitation, such as malaria and dengue. Experts say we've already seen examples of this impact, from epidemics of cholera in Bangladesh to Rift Valley fever in Africa.

Laura Grant, posting on Treevolution, adds that climate change's effects have been seen in Kenya too.

“The Intergovernmental Panel on Climate Change has warned us that the range of vector-borne diseases like malaria is likely to change thanks to climate change. Kenya has already reported cases of the disease in previously malaria-free areas.”

Though climate change is a global phenomenon, experts warn that its health consequences will be the most severe for the poorest people in the poorest countries. Approximately 600,000 deaths occurred worldwide because of weather-related natural disasters in the 1990s and some 95 percent of these were in poor countries. Also, diarrhea, malaria and protein-energy malnutrition, which are all impacted by climate, caused more than 3 million deaths globally in 2002; over one third of these deaths happened in Africa. This photo gallery illustrates more health consequences of climate change.

However, the blog Globalisation and the Environment points out that it's hard to separate climate change and poverty's impacts on health.

“There is considerable debate about the effect of global warming on the spread of diseases. Try to remember that there is a close relationship between poverty and disease as well as between disease and climate. That point aside it is always of interest to a dismal scientist to consider alternative ways that we can die.”

Scientists at the Wildlife Conservation Society (WCS) have done just that — they released a report earlier this month naming 12 animal-human diseases that might spread to new regions of the world because of changes in temperature and rainfall. The “deadly dozen” diseases include avian flu, cholera, Ebola, Lyme disease, tuberculosis, and yellow fever. In order to prevent a major outbreak, the WCS recommends better monitoring of wildlife health to help detect how these diseases are moving. trimurtulu, posting on MeDiCaLGeeK, elaborates on their suggestions:

“The authors suggest that the best way to protect ourselves against worst possible scenarios is to track how the diseases shift through wildlife populations by establishing a global surveillance network based on a mix of Western science and the knowledge of indigenous people.”

The report has scared some bloggers, such as one blogging on ThinkingShift, into considering the connection between disease and climate. She says:

“We’re so absorbed right now with the financial fracas going on that if we think about climate change, we think of regions heating up, sea levels rising, poor polar bears unable to find ice floes to rest on and so on. But do we ever stop to think about the deadly diseases that we might face? Well, this report sure helped me think about it especially the fact that pathogens, which pose a threat to humanity, have already caused significant economic damage. The SARS virus and avian influenza, for example, have already caused an estimated US$100 billion in losses to the global economy.”

The World Health Organization (WHO) says that unless adaptive measures are taken, climate change is projected to approximately double by the 2050s the percentage of its population at risk of hunger and associated health effects. Maina, blogging on Baraza, proposes multiple solutions to combat this problem.

“One, we have to adopt sustainable living as humans to reduce the severity of climate change and its effects; two, now more than ever, we have to safeguard our wildlife for they are our early warning systems against outbreaks of these deadly diseases.”

However, leg-iron accuses WCS's report of being scaremongering with no scientific basis. Peri Urban, blogging on the urban blog, adds that very little research exists on this topic and that the link between climate change and health hasn't been proven yet.

“There are no ‘adverse effects’ that we know of from which the WHO should feel obliged to protect us. Nor is it possible to raise public awareness of an issue that is yet to be researched, unless your aim is to generate the advance belief that there is a problem so that you can get funding. Scientists have mortgages to pay just like the rest of us.”

Photo of Cherry Blossoms In January by Night Heron on Flickr.

Start the conversation

Authors, please log in »


  • All comments are reviewed by a moderator. Do not submit your comment more than once or it may be identified as spam.
  • Please treat others with respect. Comments containing hate speech, obscenity, and personal attacks will not be approved.