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Climate change deniers trying to fool the public again about extreme weather
Commentary on 15 February, 2019
Flooding in Houston, Texas in the aftermath of Hurricane Harvey (Credit: Karl Spencer/istock)
Climate change deniers in Britain are continuing to mislead the public and policy-makers by wrongly claiming that there has been no change in extreme weather over the past few decades as the impacts of climate change have grown.
Members of the Global Warming Policy Foundation, which was set up by Lord Lawson to campaign against policies to reduce greenhouse gas emissions from the use of fossil fuels, frequently misrepresent the scientific evidence that the risks of heatwaves, tropical cyclones, droughts and flooding due to heavy rainfall are rising in many parts of the world.
Last year, Ofcom, the communications regulator, found that the BBC had breached its own editorial code on accuracy by broadcasting false information about climate change during an interview with Lord Lawson on the 'Today' programme in August 2017.
Lord Lawson, who last month stepped down as the Foundation's chair and was appointed its "honorary president", had wrongly asserted that "all the experts say there hasn't been" an increase in extreme weather events and that the Intergovernmental Panel on Climate Change (IPCC) "concedes" this fact.
But the IPCC Fifth Assessment Report in 2013 actually concluded: "Changes in many extreme weather and climate events have been observed since about 1950".
Ofcom ruled that Lord Lawson's statements were not correct and that he should have been challenged about their lack of veracity during his interview.
But it is not only through statements by its Trustees that the Foundation, which was sanctioned by the Charity Commission in 2014 for promoting climate change denial, spreads misinformation about extreme weather.
Last month, the Foundation published an inaccurate and misleading pamphlet on 'Tropical hurricanes in the age of global warming'. Written by Paul Homewood, a retired accountant, it contains a number of false statements, including: "Historical data shows that Atlantic hurricanes, particularly major ones, were much more common between about 1930 and 1960 than in the following decade. Since 1990, the numbers have returned to earlier levels. It is widely accepted that this pattern is linked to the Atlantic Multidecadal Oscillation (AMO), a naturally recurring cycle of temperature changes in the sea surface temperature."
In fact, the United States Fourth National Climate Assessment in 2017 found: "Determining the relative contributions of each mechanism to the observed multidecadal variability in the Atlantic, and even whether natural or anthropogenic factors have dominated, is presently a very active area of research and debate, and no consensus has yet been reached. Despite the level of disagreement about the relative magnitude of human influences, there is broad agreement that human factors have had an impact on the observed oceanic and atmospheric variability in the North Atlantic, and there is medium confidence that this has contributed to the observed increase in hurricane activity since the 1970s."
Mr Homewood's pamphlet also cites a review paper on 'Tropical cyclones and climate change' by Kevin Walsh and co-authors, but omits any acknowledgement of the following conclusion: "Confidence has now increased to 'medium' that in the Atlantic basin, external forcing factors such as anthropogenic greenhouse gases and aerosols are partly responsible for the increase in TC [tropical cyclone] formation since the comparatively quiescent 1970s–1980s".
The press release issued by the Global Warming Policy Foundation to publicise the pamphlet quotes Mr Homewood as saying wrongly that "if you look at the Atlantic hurricane records or the shorter global record: there is simply no increase in activity".
Mr Homewood has been active again this week, using his personal blog to try to discredit information about extreme weather events that appear in a new report by the Institute for Public Policy Research (IPPR) on 'This is a crisis: Facing up to the age of environmental breakdown'.
He focused his attack on the following statement: "Since 2005, the number of floods across the world has increased by 15 times, extreme temperature events by 20 times, and wildfires sevenfold." This was attributed to an analysis of information in EM-DAT, the international disaster database carried out by Jeremy Grantham, whose Grantham Foundation for the Protection of the Environment provides funding to the London School of economics and Political Science for the Grantham Research Institute on Climate Changeand the Environment.
IPPR immediately recognised that its statement contained a typographic error, and corrected it so that it referred to trends since 1950.
But Mr Homewood argued that the statement was a "fake claim" anyway because the EM-DAT database is incomplete for disasters before 1998.
In fact, there are many other reasons to be cautious about trends in extreme weather events calculated from the EM-DAT database. The most important is that it only includes disasters that killed 10 or more people, or affected 100 or more people, or resulted in a declaration of a state of emergency or a call for international assistance. Many extreme weather events fall beneath this threshold and so are excluded from the database.
Other important factors that need to be taken into account include the increase in the global population which means the number of people who could be affected by extreme weather events has grown since 1950. On the other hand, many parts of the world have improved their resilience against extreme weather events and protect more people against their consequences.
In short, one should be cautious about interpreting trends in extreme weather events from the EM-DAT database, or indeed from any of the incomplete available data. It is worth noting that Mr Grantham's paper, which accurately reports the trends that can be calculated from the EM-DAT database, described it as "a quick survey".
Nonetheless, it is also worth recognising that many other analyses of extreme weather have also noted changes in frequency and intensity, including the IPCC Fifth Assessment Report, which states:
"Changes in many extreme weather and climate events have been observed since about 1950. It is very likely that the number of cold days and nights has decreased and the number of warm days and nights has increased on the global scale. It is likely that the frequency of heat waves has increased in large parts of Europe, Asia and Australia. There are likely more land regions where the number of heavy precipitation events has increased than where it has decreased. The frequency or intensity of heavy precipitation events has likely increased in North America and Europe. In other continents, confidence in changes in heavy precipitation events is at most medium."
Hence Mr Homewood's allegation that the IPPR report contained "lies" is without any foundation.
Mr Homewood ended his blog with the entirely untruthful claim that "even the IPCC never made such outlandish claims, and could find no real evidence that extreme weather was increasing, despite intense efforts to do so".
False allegations about the IPPR report have also been strongly pushed by other climate change deniers who are affiliated to the Global Warming Policy Foundation.
Viscount Ridley, who is a member of the Foundation's "Academic Advisory Committee", chose to highlight a bogus suggestion by another denier that Jeremy Grantham had funded the report via a donation to the European Climate Foundation.
He tweeted: "So now the greens are getting not just their money but also their pseudoscience from a billionaire".
In fact, the Grantham Foundation is just one of many funders listed openly on the website of the European Climate Foundation, which provided no money for this IPPR report.
Not only was Viscount Ridley's claim misleading, it was also extremely ironic. Climate change deniers were able to identify the European Climate Foundation from a list of funders which IPPR transparently publishes on its website.
By contrast, the Global Warming Policy Foundation, which Viscount Ridley advises, keeps its sources of financial support entirely secret.
The Foundation's latest accounts, which were published on the website of Companies House earlier this week, reveal that it has received £624,024 over the past two years from donors whose identities are kept hidden.
So we do not know who exactly is paying for Mr Homewood's pamphlets for the Foundation.
Bob Ward is policy and communications director for the Grantham Research Institute on Climate Change and the Environment and the ESRC Centre for Climate Change Economics and Policy at the London School of Economics and Political Science.
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