a) Is the climate changing?
90% of Britons reported that they believed the climate is changing. 41% said a lot, 49% said a little. These figures are down very slightly since 2006.

b) Perceived impact on future generations
Respondents were asked to assess how much climate change would affect future generations. 85% reported that it would impact ‘a great deal’ or ‘quite a lot’. This figure is down from 89% in 2006.

c) Concern about climate change
76% said they were concerned (either ‘very’ or ‘fairly’) about climate change. This figure has declined 5% since 2006.

d) Willingness to change behaviour in response to the climate change problem
About three quarters (74%) said that they ‘agreed’ or ‘agreed strongly’ with the statement ‘I would be prepared to change behaviour to help limit climate change’. The DfT survey does not give a comparable figure for 2006

e) Cutting car use for the sake of the environment
Just over half (58%) of respondents agreed with the statement that ‘individuals should try to limit car use for environmental reasons’. This figure is down 4% since 2006.

The survey also asked about the contrasting statement ‘people should be allowed to use their cars as much as they like even if [they cause] environmental damage’. 37% of people agreed with this statement, up sharply from 26% in 2006. To emphasize this point; more people said that car drivers should ignore environmental issues than said that they would not be prepared to ‘change behaviour to help limit climate change’ (point d).

f) Personal actions
The survey then asks people what they themselves would be prepared to do in the next twelve months to help limit climate change. Recycling was mentioned by about nine in ten (i.e. about the same number that said that the climate of the UK is changing) but only about a quarter mentioned restricting the number of flights that they took. Only about 10% agreed with increasing the tax on petrol (down 4% since 2006).

g) Actual behaviour
The DfT survey does not ask about what people have actually done to reduce their own responsibilities for emissions. But we know from other survey work that a relatively small number of people have taken significant and painful action on personal emissions. Most people now recycle actively and have installed low-wattage light bulbs. Only about 5-10% have decided to stop flying or not to own a car for environmental reasons.

Points a) to g) suggest the following hierarchy:

Broadly speaking, other survey results show the same numbers and also repeat the small decline in the percentages of those worried or acting on climate. But, to repeat, the very cold UK winter of 2009/2010 and the stream of revelations about the IPCC and the CRU may have pulled all these figures down further.

The malaria life cycle. Source: University of Tuebingen.

A recent press release from the UK Department for International Development (DFID) suggested that millions more people in Kenya are susceptible to malaria as a result of mosquitoes colonising higher ground as global temperatures rise. (‘New evidence of a link between climate change and malaria’, 30.12.09 – see below). The press release was extensively covered in UK newspapers and elsewhere.

Simple analysis shows that the claims of the press release are almost entirely without foundation. The battle against the severe threat from climate change is impeded, not helped, by government departments issuing alarmist and exaggerated alerts based on poor science.

All other things being equal, the spread of malaria is probably encouraged by higher global temperatures. The malaria parasite in the insect’s body grows fastest at average daily temperatures of about 25 degrees and most parts of the world are well below this level. But temperature is only one factor in the spread of this terrible disease, possibly a small one. The presence of stagnant water in open sunlit fields after deforestation, increased population pressure, lack of availability of mosquito nets, or a reluctance to use them, may all contribute as much to the spread of malaria as increasing temperatures. Nevertheless, despite the plethora of more convincing explanations for varying levels of malarial illness, policy-makers and government departments continue to state, without any qualification, that malaria will become very much more prevalent in a warmer world.

The 2001 IPCC report also overstated the connection between climate change and malarial infections. Understandably, the top-selling books by climate sceptics published in the last few years all feast on the weak scientific evidence for this assertion. These books usually quote the specialist in insect-borne diseases, Professor Paul Reiter of the Pasteur Institute in Paris, who has strenuously and effectively attacked the idea that increasing temperatures will necessarily produce a rapid rise in the incidence of insect-borne diseases. Professor Reiter points out that malaria transmission is a complex matter and that rising temperatures are only weakly linked to an increasing incidence of malaria. (The illustration at the head of this article provides us with some sense of just how complex malaria is.) Why, he and others have asked, if temperature is so important, did the disease disappear from countries like Britain just as the climate was warming at the end of the ‘Little Ice Age’ during the eighteenth and nineteenth centuries?

However, the story that substantial increases in malaria will inevitably follow rising temperatures will not go away and DFID’s recent press release is another example. The document claims that ‘new research’ in the highland areas around Mount Kenya has shown strong links between increasing temperatures and malaria incidence. When I asked for a copy of the scientific papers to back up this assertion, DFID said it was unable to provide this ‘new research’, stating instead that the press release was based on ‘a cumulation of several studies over the past few years’.

Three papers were attached to this surprising response from DFID. The press release asserted that temperatures on the western side of Mount Kenya had risen two degrees Celsius in twenty years, prompting epidemics of malaria, but these research papers actually showed a much smaller increase. The specific claim that the Mount Kenya area has recently become vulnerable to malaria was backed up by interview data of a few years ago from a small number of families who declared a total of eight cases of malaria in the past five years compared to only three in the period of five to ten years ago. No medical analysis appears to have been carried out to determine whether the disease recorded was or was not malaria. Neither was any attempt apparently made to adjust for deficiencies in memory of events ten years ago.

What about the physical evidence of mosquitoes? The scientific papers sent to me by DFID write of finding a total of two mosquito larvae in pools on high ground near Mount Kenya. These larvae produced a total of 23 insects when incubated in a laboratory. The quality of this finding is never questioned. Most importantly, the background research papers do fully acknowledge that other events in the geographic areas under study, such as deforestation or increased pooling of stagnant water as a result of land-use changes, could well have been the primary cause of any growth in the number of mosquitoes and of malaria, not climate change. But these possibilities are unmentioned in the DFID press release.

A line-by-line analysis of the press release is provided below. It suggests that almost all the assertions in the DFID document are unsupported by any evidence or are downright wrong. Malaria may indeed be increasing in highland areas of Kenya but the evidence that the disease is driven by rapid climate change is completely unsupported. The research used by DFID and sent to me actually states that changes in land-use may be the key factors in encouraging the growth of this extremely unpleasant disease.

The climate sceptics often claim that the political establishment routinely exaggerates the effects of increasing temperatures. These sceptics say that very poor scientific evidence is used to create alarmist headlines about the impact of global warming. The DFID press release is a clear candidate for criticism of this type. It has used inadequate scientific research as the basis for an unqualified conclusion about the impact of climate change on insect-borne diseases. In this case, the press release goes even further by mis-stating many of the elements of the research on which it is based. Such abuse of science does substantial disservice to the attempt to energize the global community to take action to mitigate climate change.

(With many thanks to Professor Paul Reiter for his comments during the preparation of this article. Errors are my responsibility. If you are interested in reading more about the causes of malarial infections, please consult one of Professor Reiter’s papers.)

***

[Press release sent out by DFID with my notes in bold:]

New evidence of link between climate change and malaria

New research released today shows a direct link between rising temperatures and the spread of malaria.

a) The research is not new. The key scientific papers to which the press release refers were published in 2001 and 2006. The research was carried out by Dr Githeko of the Kenya Medical Research Institute and his colleagues. Dr Githeko contributed a summary of this earlier research and of other recent findings from around the world for a Commonwealth health ministers meeting in 2009.

c) The research does not show a ‘direct link’ between malaria and average temperatures. The 2001 paper actually says: ‘Land use pattern and land cover might be the key factors affecting [...] malaria transmission in the region’.

Four million people living on the slopes of Mount Kenya in the Kenyan Central Highlands are now at risk of malaria, after warmer temperatures pushed the disease into high altitude areas where the population has little or no immunity.

a) The 2001 paper says: ‘With the increased population on the highlands, enhanced human activities including deforestation, farming and livestock rearing could create more vector [i.e. malaria carrying mosquitoes] habitats’. It does not say climate change is causing malaria.

b) The 2006 paper says in reference to Western Kenya, over 200 km from Mount Kenya, that the researchers had found ‘an association between rainfall and unusually high maximum temperatures and the number of inpatient malaria cases 3-4 months later’. It makes no reference to the slopes of Mount Kenya.

The findings, announced today by a research team from the Kenyan Medical Research Institute (KEMRI) partly funded by the UK Department for International Development (DFID), also show the number of cases recorded during malaria epidemics has increased by up to 600% over the past decade.

a) The findings, at least as provided in the back-up reports provided by DFID, do not show this. The only mention of malaria cases in this research is as follows: ‘In Karatina and Naro Moru areas where An. Arabiensis [one of the malaria mosquitoes] was detected, the numbers of malaria cases recorded were eight in the past 5 years, three in the past 5-10 years and none in the past 10-20 years, indicating a trend of increasing malaria incidence over the past 10 years.’

b) Malaria may well be becoming an even more serious problem in Kenya, and rising temperatures may indeed contribute to the incidence of this disease. But DFID provides no evidence to support its assertion about the Mount Kenya region. Dr Githeko’s 2009 summary paper does mention third-party research showing an ‘eight-fold’ increase in malaria in Western Kenya (not the Mount Kenya area) and this may be the basis for the DFID assertion.

While similar outbreaks elsewhere have been attributed to multiple factors such as drug resistance and land use change, the research team claim the only change that has occurred recently in the Kenyan Central Highlands that might lead to malaria is an increase in the mean annual temperature.

a) Dr Githeko’s 2009 summary paper says that ‘In the central highlands the only change that occurred and that lead [sic] to malaria was the mean annual temperature’. But in this and the other papers, he also pointed to variations in rainfall, increases in maximum daily temperatures, changes in land use, greater population density, deforestation, irrigation, and stagnant water as having an effect on malaria rates. Dr Githeko’s comments are inconsistent, even within single papers.

The spread of malaria into the Central Highlands district followed a rise in average yearly temperatures from 17 degrees in 1989 to nearly 19 degrees today. The malaria parasite can only mature in temperatures above 18 degrees.

a) Prior to 1994, the mean annual temperature in the Central Highlands region is said by Dr Githeko to be ‘between 17.4 degrees C and 18.2 degrees C’. Dr Githeko does not provide data for recent years. His record stops at around 2002.

b) The average annual temperature does not have to be above 18 degrees for the malaria parasite to mature. The parasite requires periods of higher temperatures to grow but it can mature in a few days of warm weather. The annual mean is not a particularly relevant measure. (Some northern European countries were infested by malaria until the twentieth century and their annual average temperatures were well below 18 degrees C.)

Before the 1990s malaria was completely absent in the Central Highlands district. However, as climate change pushed average temperatures over the 18 degree tipping point in the 1990s, malaria epidemics began to break out among the population.

a) As said before, mean annual temperatures rising above 18 degrees do not create a ‘tipping point’ for malaria. Recent years may have seen malaria increasing in the Mount Kenya region, partly perhaps as a result of global warming but, second, the DFID papers provide no evidence whatsoever of ‘epidemics’.

Malaria has continued to spread in populations with little immunity to the disease. In 2005 malaria-carrying anopheles mosquitoes were discovered in Naru Moro, over 1,900 metres above sea level.

a) Dr Githeko found two (2) mosquito larvae in 2005 in Naru Moro, not mosquitoes. Larvae do not carry malaria. The mosquito carries malaria after it has ingested the blood of a person with the disease.

b) DFID is wrong to state that Dr Githeko’s findings show that ‘malaria has continued to spread in populations with little immunity’ and to associate this conclusion with his finding that the two Naru Moro larvae showed this continuing spread.

The KEMRI researchers were funded by the Department for International Development (DFID) and the Canadian International Development Research Centre (IDRC).

[Press release then continues with quotations for journalists.]

Image source: The Sydney Institute.

Professor Ian Plimer is one of the most influential global warming sceptics. A university academic in Australia, his trenchant views on climate change have helped persuade opposition politicians in his home country to back away from supporting schemes to reduce emissions. His book Heaven and Earth: Global Warming: The Missing Science (reviewed here last month) remains a best-seller in the UK.

He spoke in central London on 1 December at a meeting organized by the anti-EU United Kingdom Independence Party (UKIP). The material in the talk was largely taken from his book, though his language was even more open and unrestrained. Unsurprisingly, in view of the controversy over the content of recently exposed CRU emails, he repeatedly used the word ‘fraud’ or ‘fraudulent’ to characterize the views of his opponents. He described his critics as ‘rent-seekers’ who spent their time seeking out the next research grant.

This article takes a small number of the more controversial statements made by Professor Plimer and sets them against the standard scientific view.

***

The role of CO2 in climate change
The burning of fossil fuels and the cutting down of forests adds to CO2 in the atmosphere. Carbon dioxide acts as a blanket, assisting the world’s atmosphere in retaining heat. More CO2 means more heat retention, say the textbooks. If we continue adding global warming gases, global temperatures will rise.

Does Plimer agree with this? During the talk he said that ‘doubling CO2 would have very little effect on temperature’. Higher CO2 levels in the future would have ‘negligible’ impact. At another time he said it would have absolutely no effect.

In a brief chat after the speech, I asked the professor to be more specific. What was his estimate of the impact so far on global temperatures of the CO2 mankind has added to the atmosphere? ’0.1 to 0.3 degrees’ (Celsius) was his response. The conventional scientific answer to this question might be about three times this figure.

Professor Plimer went on to say that his figures are lower than the IPCC estimates because the standard science is wrong about the absorption of CO2 in natural sinks such as the oceans. The typical residence time of carbon dioxide in the atmosphere is seven or eight years, he said. This is a much, much lower figure than proposed by conventional science. The standard view, sometimes called the Bern Carbon Cycle model, sees some of a pulse of new CO2 being removed rapidly from the atmosphere but also suggests that a portion remains for hundreds of years.

I responded to Professor Plimer’s remark by asking how his views on the rapid absorption of CO2 by natural sinks could be compatible with the observed yearly growth in the atmospheric concentrations of the gas since the beginning of the industrial revolution. In 1800, CO2 accounted for about 280 parts per million of the global atmosphere. Since then, concentrations have risen to nearly 390 ppm. CO2 arising from fossil fuel combustion has a different mix of carbon isotopes to the existing ambient gas. From many analyses using this and other parts of science we know that approximately half the CO2 added to the atmosphere by man is still there. (In the body of his talk the professor asserted that the assessment of how much fossil fuel CO2 is entering the atmosphere comes from a ‘dodgy calculation’ and he does not accept isotope analysis as a way of determining the source of carbon dioxide.) I wanted to understand how Plimer’s views on the short life of CO2 in the atmosphere could be made consistent with the rate of rise of observed CO2 levels since industrialization began.

He answered by saying that science was wrong to assume that the pre-industrial atmosphere held 280 parts per million of CO2. It was actually much higher, he said. The net addition to global CO2 levels by the burning of fossil fuel is therefore implicitly substantially lower than science suggests. Plimer says that measuring techniques are inadequate and that proper measurement would show that nineteenth- and early-twentieth-century CO2 levels were much higher than is assumed and very much more variable. He said to me that the belching of carbon dioxide by volcanoes would, for example, have produced short-lived but large rises in greenhouse gas concentrations. The charts that show stable atmospheric concentrations prior to the industrial revolution are therefore wrong, Plimer said.

In the body of the talk Professor Plimer attacked the quality of even today’s Mauna Loa data. He said that the measurement techniques were flawed and that the nearby volcano emits considerable amounts of CO2 which affects the quality of the record. 86% of all the observations were rejected, he said, and only data that accorded with the scientists’ prejudices was used. The professor did not, however, mention that many other sites around the world also measure CO2 concentrations and all of these stations report the same trend. (Absolute levels are different, inter alia, because of seasonal variations in CO2 concentration in different parts of the world resulting from plant growth.)

In the space of a short conversation, Professor Plimer attacked the foundations of climate science. He said that we overestimate the impact of CO2 on climate, that carbon dioxide is absorbed by sinks very rapidly, and, finally, that the standard measures of greenhouse gas levels over the last two hundred years are substantially in error, both now and in the past. In other words, almost everything that mainstream science believes about carbon dioxide in the atmosphere is incorrect. Fifty years’ work from scientists working independently all over the world on these issues has been misdirected, flawed, biased, and ignorant.

The assertion that scientists have systematically understated CO2 levels before the industrial revolution is particularly striking. To my knowledge, no one else has ever recently suggested that the stable pre-industrial level of 280 ppm is substantially inaccurate. The sources of this figure, such as measurements from the air trapped in ice cores, are usually considered to provide robust information. The number of scientists in the world who accept Professor Plimer’s views on this issue is vanishingly small. As far as I know, none of the other leading sceptics agree with him on this issue.

But he has to believe that the standard charts are wrong, even if this makes him even more at odds with the scientific establishment on this issue than other sceptics. If CO2 has risen by over 100 ppm in the last couple of centuries, he would have to accept that the gas has a much longer residence time in the atmosphere than he hypothesizes. And this would be incompatible with his view that CO2 is only responsible for ’0.1 to 0.3′ degrees of the rise in temperature since large-scale burning of fossil fuels began.

However, Professor Plimer had not even been consistent about whether world temperatures had risen at all. At some points in the body of his talk, he said that levels were rising, but this is ‘normal’. At other points, he said it was falling or stable. At yet other moments, he acknowledged some regional warming but said that large areas of the globe were getting colder. I believe that a dispassionate observer listening to Professor Plimer would have struggled to understand what he really believed about temperature rises, absolute CO2 levels or, most importantly, the effect of CO2 levels on temperature.

Nevertheless, he railed strongly against the theoreticians and the careful scientists who work on climate change. His principal charge was that they never go out into the real world to make their own observations. He said that they were ‘people in basements’ running computer models to appeal to their political masters and that only the sceptics were real scientists. Conventional science and its models made you ‘bang your head with boredom’. By contrast, he said that his thoughts on climate change provided a ‘far more evocative and sensual’ story and are therefore more likely to be right than conventional science.