Who Says Climate Change is Bad?

Timothy Birdnow

This piece has appeared in Project Shining City and Canada Free Press:

Mosquitos are disappearing in Africa.

According to this report in The University of Copenhagen/Malaria Journal:

http://www.infection-research.de/news/detail/pressrelease/the_malaria_mosquito_is_disappearing/

"The incidence of malaria in many African countries south of the Sahara is falling rapidly. A Danish-Tanzanian research group has discovered that the mosquito carrying the malaria parasite has practically disappeared from villages without organized mosquito control, and the researchers do not know why. There are several hypotheses but without proper data they cannot say whether malaria is being eradicated or whether it is just resting up before returning with renewed vigour. The team reports their findings in the Malaria Journal.

"Many of our fellow malaria researchers think that the fall in countries such as Tanzania, Eritrea, Rwanda, Kenya and Zambia shows that all the control programmes are working, particularly the use of mosquito nets," says Associate Professor Dan Meyrowitsch from the Department of Health Services Research at the University of Copenhagen...'

End excerpt.

The researchers speculate that this is a result of climate change; the rainfall patterns have changed since the 1990's and it is possible that:

"From 2003 to 2009 the volume of precipitation was more stable, but the rain was more chaotic and fell outside the rainy season. And this may have disturbed the natural cycle of mosquito development," he says. "Of course it is great that the number of malaria-related fatalities among children has fallen drastically in the last five or six years, but we need to know why."

End excerpt.

See the pdf here. http://www.malariajournal.com/content/pdf/1475-2875-10-188.pdf

Perhaps. It seems likely that some sort of natural event is occuring, like the disappearance of bees. But could it also be the work of an old friend?

According to this 2009 article in Scientific American:

http://www.scientificamerican.com/article.cfm?id=ddt-use-to-combat-malaria

In 2007, at least 3,950 tons of DDT were sprayed for mosquito control in Africa and Asia, according to a report by the United Nations Environment Programme.

"The volume is increasing slowly," said Hindrik Bouwman, a professor in the School of Environmental Sciences and Development at North-West University in Potchesfstroom, South Africa, who also served on the panel."

End excerpt.

In point of fact, in 2006 the World Health Organization reversed it's position on DDT and now promotes it's use to control malaria. http://www.who.int/mediacentre/news/releases/2006/pr50/en/ And while the researchers took such steps as mosquito netting into account when conducting their study, one must ask if they are fully aware of the use of pesticides. The Southern African Development Community has recently announced they will begin an aggressive program of spraying with DDT.
http://www.american.com/archive/2011/april/africans-tell-the-un-to-buzz-off

The researchers believe there was no residual spraying at their test sights, but do we really know that is the case? Has DDT been used despite the U.N. ban? It seems strange that many African nations are pushing the use of DDT (particularly as a residual treatment) and the decline in numbers of mosquitos. The authors of the study admit that a non-targeted use of pesticides may be the answer - or at least one answer - to what is happening. Is DDT being used to control agricultural pests?

At any rate, the researchers conclude that pesticides are but a part of the decline of the hateful little pests. But if climate change is responsible, isn't that a good thing? Perhaps we will see a worldwide decline in mosquitoes and the diseases they transmit. This alone would make up for any ill effects caused by global warming - either natural or anthropogenic. Mosquitoes are one of the worst scourges of nature.

Who really will miss them?

End.

I contacted Richard Tren at Africa Fighting Malaria about the matter and he had this to say;

Dear Mr. Birdnow,

Thanks for your email. To be honest, I’m not really sure about the black market use of DDT – but its very nature it is very difficult to know how much insecticide is stolen and sold on. I have heard from credible scientists and program managers that some amount of insecticide, whether DDT or other chemicals, is always lost. I’m just not able to say how serious the problem is. Although I think that the ecological or human health impacts of using DDT are likely to be slight or even zero, this is obviously not something that I would approve of. It is really important for the malaria programs to maintain tight controls over the insecticide used – any losses means that spray coverage will be reduced and risks to people from malaria will increase.

I saw the paper on the drop in mosquito numbers, but I’m not really able to comment. It doesn’t appear that insecticides were the cause here, it might be climatic or some other cause. More studies would need to be done in other areas to see what the possible cause may be and also what the potential impact on malaria transmission might be.

Thanks

Richard

So my speculations on illicit DDT use cannot be validated. Still, it makes me wonder; Africa is returning to a tried-and-true "skeeter killer" and their numbers are dropping precipitously. Of course, there are other factors; changes in land use, better housing, etc.