Back in 2001, the University of Florida wrote one of those “science by press release” thingy’s in Eurekalert where they speculated that global warming would increase ranges, and thus the range of mosquito borne disease.
The next year, NPR jumped into the fray with Is Global Warming Nurturing Parasites?
In 2006 it was Warming Trend May Contribute To Malaria’s Rise in Science Daily
In 2009 Gore gets bitten again by another factual blunder getting all worked up about mosquitoes in Nairobi.
Joltin Joe Romm and NYT’s Andrew Revkin agreed last year that:
The climate blogger Joe Romm and I agree (breaking news): Scientific research and assessments examining the link between human-driven climate change and malaria exposure have, for the most part, accurately gauged and conveyed the nature of the risk that warming could swell the ranks of people afflicted with this awful mosquito-borne disease.
Also in 2010, Indur Goklany did a WUWT guest post Smacking Down Malaria Misconceptions as well as this guest post from Dr. Pat Michaels where clearly the malaria data just doesn’t add up in Peer reviewed whack a mozzie.
I’m happy to report both Romm and Revkin are wronger than wrong, and the whole AGW to malaria link has just been shot down, in Nature no less, by a Penn State study. It may also be time to revist this WUWT post: Mann’s 1.8 million Malaria grant – “where do we ask for a refund’? since he didn’t contribute to this new study.
Here’s excerpts from the story in Nature:
Global warming wilts malaria
Transmission of infectious parasites slows with rising temperatures, researchers find.
A common assumption is that rising global temperatures will increase the spread of malaria — the deadly mosquito-borne disease that affects millions of people worldwide. But a study out today in Biology Letters finds that warmer temperatures seem to slow transmission of malaria-causing parasites, by reducing their infectiousness.
The study was done with rodent malaria, but the researchers, at Pennsylvania State University in University Park, expect the pattern to apply to human malaria and possibly to other mosquito-borne diseases such as dengue fever and West Nile virus.
Studies predicting that warmer climates will increase malaria infections commonly assume that the disease-causing parasites will develop faster and that the ability of the mosquito to acquire, maintain and transmit the pathogen will remain constant. They conclude that as temperature rises, mosquitoes become infectious quicker and therefore malaria transmission increases.
But the latest study shows that temperature has a more complex effect. As temperature rises, parasites do develop faster, but fewer of them become infectious.
“It is a trade-off between parasite development and parasite survival,” says Krijn Paaijmans, an entomologist and study author. “And if you don’t factor this in I think you come to the wrong conclusions.”
To tease out the factors involved, Paaijmans and his colleagues incubated mosquitoes infected with Plasmodium yoelii, which causes rodent malaria, at 20, 22, 24 and 26 degrees Celsius for 5–14 days. The researchers then examined the salivary glands of the mosquitoes — where the parasite travels when it is mature — and found that the parasite developed more quickly in warmer temperatures. But they also found fewer sporozoites — the infectious form of the parasite — indicating that the mosquitoes were less infectious at higher temperatures.
==============================================================
Full story here
Will Romm finally shut up about mosquitoes and malaria now? Will Revkin write a story correcting his previous ones? Will Mike Mann give back the 1.8 million dollars?
UPDATE: In comments, Andrew Revkin disputes that he was “wrong” on malaria per the quote I cited from the Climate Progress article. He now points to his 2010 article: ‘The science linking warming and malaria risk was always iffy‘ He says he was taken out of context and that his quote was poor word construct. – Anthony
When pigs fly, when hell freezes over and no.
We can be assured and relieved that CAGW fanatics will devote just as much energy to spreading “good news” like this as they did to spreading alarmist news when they thought that the “malarial mosquitoes hypothesis” served their agenda. (sarcasm alert)
Malaria was endemic in Northern Russia and Siberia, during the Little Ice Age.
http://climateaudit.org/2005/08/30/mosquitos-malaria-and-the-ipcc-consensus/
Suggesting Malaria is a tropical disease is pure hokum. The only reason we dont face Malaria epidemics on the same scale as the tropics does, is many of the swamps in developed countries, where the Mosquitoes used to breed, got drained, paved over, and sold as housing estates.
We also fought a successful battle to eradicate Malaria mosquitoes, with techniques ranging from the 19th century method, of covering swamps in a thin layer of Castor Oil, to spraying infested areas with chemicals like DDT.
Of course, when Africa started using DDT, we banned it.
Of all the crimes against humanity committed by 20th century Environmentalists, history may judge their worst crime to be the murder of millions of Africans, by depriving them of the means to control Malaria.
Off topic – but in the same vein – here is a story from the BBC where trees are dying but amazingly not declared due to climate change!!
http://www.bbc.co.uk/news/science-environment-16270759
Interesting article, although as David Stern already pointed out the study in question was performed with rodent malaria. I imagine that it is pretty safe to assume that ‘human’ malaria acts in the same way to temperature changes, but it would it unscientific to state that the issue has been ‘settled’ without direct experimental evidence, would it not…?
Eric Worrall says: December 20, 2011 at 11:49 pm
“Of all the crimes against humanity committed by 20th century Environmentalists, history may judge their worst crime to be the murder of millions of Africans, by depriving them of the means to control Malaria.”
That isn’t true. DDT use for malaria control was never banned by the Stockholm Convention, and continued in Africa (and India and S Am) throughout. Its use diminished because of insect resistance. Here is a recent Stockholm Convention report on the current and planned use of DDT.
Once again, a simplistic AGW poster story skewered by the complexity of its details. This does explode the standard myth but these details suggest that this isn’t THE simplistic ‘answer’ to it either. It is just one paper on just one species.
In the meantime, good news for rodents worried about the relentless warming.
Didn’t Paul Reiter resign from the IPCC over this issue?
Paul Reiter is an expert in malaria and he is of the view that malaria thrives in cold conditions and the IPCC misrepresents the case that warming would lead to an increase in malaria. I am sure that Paul Reiter will welcome this latest paper vindicating his position.
Further to my last post, the language of which was a bit sloppy. I understand that Professor Reiter holds the view that malaria is not a tropical disease and that malaria carrying mosquitos can thrive in cold climates and since it is not a tropical disease warming per se will not inevitably lead to an increase in malaria. .
I wonder if the University of East Anglia will remember that until the middle of the nineteenth century their part of England was notorious for malaria. This period was the same as the little ice age when lakes, rivers and canals in the area regulary froze over and the whole region was famous for winter skating.
Interesting article that makes a mockery of the alarmist non sense. I have but one problem mankind carries a disease and mozzies can spread it to other people.
This gives mozzies a bad rap, around every third generation after being vegetarian and living on plant sap, the females of the species become vampires. They need a blood diet to breed successfully , the easiest target is a naked ape, thus we are stricken by attacks of female vampire mozzies.
They are doing what is necessary for their survival . This should in no way be identified with female behaviour in general, and innuendo and sarcasm in that direction should be disregarded.
This study proves only that mozzies are doing what they do naturally, and AGW does not bother mozzies in the slightest. From the arctic to the tropics and to the netherworld of the antipodes they prosper.
Seems to me this isn’t quite a slam dunk. They only studied half the equation.
What happens to the development and transmission of the disease from the host side? Does it develop in rodents/humans faster or slower, and is it more transmissable (is that a word?), in those exact same temperature ranges? Would the overall rate of infection not be subject to both factors? If one goes down, but the other up….
Mods ~ since the transmissable sporozoites are BORN in the gut of the mosquito, the correct spelling in this case for the article title would be BORN, not BORNE. Please change it back 🙂
In climate science studies the opposite of everything is true.
This myth died a long time ago. Where is Al Gore when you need him?
One of the worst outbreaks of Malaria occurred in Russia / Siberia.
Global malaria has been on the decrease during the hottest years on the record. It’s worse than we thought!
http://dx.doi.org/10.1038/nature09098
http://dx.doi.org/10.1504/IJGW.2011.038371
I could go on with Malaria in England in the Little Ice Age, past, devastating malaria outbreaks in Finland, Norway, Canada but I think this is enough. ;O)
When was the Little Ice Age? How cold was Finland?
Brrrrr! Why does Malaria like the cold so much?
http://www.ingentaconnect.com/content/esa/jme/1986/00000023/00000001/art00009
http://www.malariajournal.com/content/7/S1/S3/.%20HTTP://.%20HTTP://WWW.MARA.ORG.ZA
“David Eyles says:
December 20, 2011 at 10:26 pm
Right up until the 1890s, malaria was endemic in the Essex and Kent marshes (low lying areas on opposite sides of the Thames Estuary). That was at the end of the period that we now know as the Little Ice Age. Warming and drainage of the marshes in the early 20th Century finished the malaria off.”
Hence the call to restore wetlands.
Nick Stokes says:
December 21, 2011 at 1:21 am
That isn’t true. DDT use for malaria control was never banned by the Stockholm Convention, and continued in Africa (and India and S Am) throughout. Its use diminished because of insect resistance. Here is a recent Stockholm Convention report on the current and planned use of DDT.
————————————————–
EDITORIAL
Bring Back DDT, and Science With It!
By Marjorie Mazel Hecht
(Full text of Editorial from Summer 2002 issue
http://www.21stcenturysciencetech.com/articles/summ02/DDT.html & http://www.21stcenturysciencetech.com/articles/summ02/Carson.html)
“The U.S. decision had a rapid effect in the developing sector, where the State Department made U.S. aid contingent on countries not using any pesticide that was banned in the United States. The U.S. Agency for International Development discontinued its support for DDT spraying programs, and instead increased funding for birth control programs.
————–
So, my understanding is that EPA administrator William Ruckelshaus made the decision to ban DDT and in every country where it was banned more people died from malaria.
Between 1826 and 1832, some 1,000 workers died of malaria while building the Rideau canal between Ottawa and Montreal, in frigid Canada. There is no malaria any more in tropical Florida. The link between malaria and climate was wrong from the start.
If Anthony had actually read the Dot Earth post he snipped from he would have seen that I was crediting Romm for acknowledging that the peer-reviewed literature did NOT point to a broadening of malaria risk. And he might have clicked on the link to the previous week’s piece that said:
Cooling Fear of a Malaria Surge from Warming.
As various arguments for action on global warming have failed to blunt growth in emissions in recent years, environmental groups and international agencies have sometimes tried to turn the focus to diseases that could pose a growing threat in a warming world — with malaria being a frequent talking point.
It shouldn’t be. The science linking warming and malaria risk was always iffy, a reality reflected in the relevant sections of the 2007 reports from the Intergovernmental Panel on Climate Change. Modeling studies cited there had variegated results, and many focused only on the potential expansion of the geographical range or mosquito-friendly seasons, while not considering how shifting patterns of health care and human behavior might render such changes moot….
http://dotearth.blogs.nytimes.com/2010/05/20/cooling-fear-of-a-malaria-surge-from-warming/
Who needs to post a correction??
Sometimes I wonder if abstract and specialized education, or just too much education, is a prime cause of these insane pseudoscience cults.
An unspecialized learner is likely to have some random facts about mosquitoes in his mind, such as the famously gigantic Alaskan mosquitoes, or the malarial swamps of Northern Ohio that caused Americans to call malaria “Maumee Fever” for many years. These facts would prevent him from assuming that skeeters need tropical warmth, or that malaria needs tropical warmth.
Well, I guess Michael Mann can return that $1.8 million
payolagrant to study mosquito vectors. It should have gone to a biologist or epidemiologist anyway. And it would have, if it were not simply payola to keep Mann in line following Climategate 1.0.Mosquito borne diseases depend on them having suitable habitats, NOT TEMPERATURE — namely stagnant, isolated water. They occur from the tropics to the Arctic.
How many times does this need repeating?
Smokey says: December 21, 2011 at 5:39 am
“Well, I guess Michael Mann can return that $1.8 million payola grant to study mosquito vectors. It should have gone to a biologist or epidemiologist anyway.”
It did go to a biologist – Matthew Thomas, principal investigator under the grant, and co-author of this paper. Mann was a co-investigator. The paper described in this post was funded by “Mann’s 1.8 million Malaria grant”.
Nick Stokes,
Thomas “said that the malaria map published in Nature shows that in some areas of Latin America, South and South-East Asia, and Sub-Saharan Africa, malaria will in fact increase with global warming.” [source]
As we see fro the comments here, “global warming” has no discernable effect on malaria, which occurs in all temperature ranges. But don’t let facts get in the way of your belief system.
http://www.jpl.nasa.gov/news/news.cfm?release=2011-387
heres another example of
its worse its worse, panic panic woe is us.