Professor Peter Stott
Professor in Detection and Attribution at the University
of Exeter and Science Fellow in Attribution at the Met Office Hadley Centre for Science and Services
February 2022
‘Scepticism is a process; denial is a position’ Introduction
Peter is a professor at the Met office with an international reputation in the field of detection and attribution of climate change. He leads the European EUPHEME project with a vision of placing extreme weather events in the context of climate variability, thereby helping European citizens adapt to a changing climate and mitigate its worst effects. Peter is also a co-editor of the annual reports published in the Bulletin of the American Meteorological Society Explaining Extreme Events of the previous year from a climatic perspective.
Whilst as scientists, we are pretty happy with the validity of induced climate change due to anthropogenic release of CO2 and its warming trajectory, many within the wider community (and some within science), have an alternative narrative, that of denial, which detrimentally gains traction in destabilising efforts to bring the climate under control. Peter described how, through his own experience as an international climate scientist, this alternative view took hold and detrimentally pushes back against established science.
Although increasing CO2 levels and consequent warming has been an acknowledged cause/effect relationship since the 19th century, it is more recently that it has become part of the political agenda, most notably from the 1990’s with support from Prime Minister Margaret Thatcher, unusually amongst political leaders a scientist by training (as is the ex-Germany leader, Angela Merkel). At the same time, American NASA scientist James Hansen raised concerns in 1988 about unintended climate change, the aim being to better inform the world about the risks of continued CO2 increase and global warming.
Mainstream global warming science has been institutionalised through the United Nations with a framework of regular updates every few years (IPCC reports). The goal of these reports is to fill a particular gap in public understanding of knowledge, risks and implications of climate change. It has produced several reports, the latest (being the 6th) has just been released. It is an international authority on climate change, its proceedings are widely agreed upon by scientists and governments and represents international collaborative science at its best. It also plays a key role in UNFCCC (United Nations Framework Convention on Climate Change). In 1992, during the UN conference on Environment and Development in Rio de Janeiro (the ‘Earth Summit’)’ nations established a formal framework for climate change action, the UNFCCC, with annual COP (Conference of Parties) meetings, the latest of which was in Glasgow (COP26) in 2021, to make progress in challenging the climate emergency.
The Science
The single most important message is that the world is warming and doing so very quickly compared to previous abrupt climate changes in the geological record (see Fig. 1).
Fig.1 Global Average Temperature Difference 1850-2021 (Met Office)
We are now ~1.2C degree warmer than pre-industrial times (~1750 A.D.). Every year since 1996 has been hotter than preceding years. It’s not a totally smooth graph, variability is introduced by El Niño/El Nina cyclic variation in the southern hemisphere which is large enough to superimpose its own short term cooling/warming effects on the general upward trend in temperatures. Half the excess CO2 now in the atmosphere has been emitted in the last 30 years. When Margaret Thatcher spoke, over 30 years ago, of ‘change and sacrifices’ to be made, CO2 concentrations were 354ppm (parts per million) and the temperature 0.3C above pre-industrial times. Any level above 450ppm and +1.5C is considered a dangerous threshold. The current CO2 level is 419ppm (see Fig.2 below).
A fundamental question is how did this carbon get into the atmosphere in the first place. It is probable that when first formed (4.5 billion years’ ago), the Earth had a CO2 atmosphere. 3.3 billion years’ ago, the first plants appeared and utilised CO2 in their photosynthetic activities. Most of this carbon was recycled but a small amount was progressively locked away in organic deposits such as coal, oil and in carbonate rocks, the result being that atmospheric CO2 levels fell dramatically. These significant, locked away deposits are now being released, through hydrocarbon burning and cement manufacture, at a rate much more rapidly than during any atmospheric changes in the past tens of millions of years.
Fig. 2 Globally averaged CO2 mole fraction (a) and its growth rate (b) from 1984 to 2019. Increases in successive annual means are shown as the shaded columns in (b). The red line in (a) is the monthly mean with the seasonal variation removed; the blue dots and line depict the monthly averages. Observation from 133 stations have been used for this analysis
One third of the carbon released today is presently absorbed by the oceans, but as these become more carbon-saturated and warmer, less carbon will be drawn down from the atmosphere. The key feature of today’s warming in the context of other warming events is the shear rapidity of change.
Another fundamental question of is whether global warming is due to natural or Anthropogenic processes. Peter’s colleague, Gabi Hegerl, has for example, used extensive climate modelling to rule out changes in solar radiation as a driver of increasing temperatures. Another colleague, Ben Santer, produced a ‘fingerprint’ of climate change. For Santer the fingerprint of warming matches the core predictions of climate models. Attention is paid to variations across different latitudes and altitudes. The most compelling fingerprint is a cooling of the stratosphere coupled with low level warming in the upper troposphere which can only be explained by increased greenhouse gases in comparison to other factors which might cause warming.
Those knowledgeable on climate change science will also know that the 12C signature of atmosphere carbon unequivocally connects burning fossil fuels with increase in atmospheric carbon.
Action and Reaction
The 1992 Earth Summit in Rio de Janeiro was widely applauded and supported by all, including George H.W. Bush (‘.. it stresses energy efficiency, cleaner air, reforestation and new technology..’) with decision making and policy enthusiastically science-based and with a unanimous intention to stabilise greenhouse gases.
The IPCC report of 1996 (its second report) was the first which said that on ‘the balance of evidence there is a discernible human influence on global climate’ (previously, it had been unable to establish a connection). This pointed the finger at fossil fuels for which there was a strong reaction and polarised views. World leaders were incentivised to mitigate its effects. The fossil fuel industry, caught on the back foot, and determined to maintain its financial pre-eminence at all costs, attacked these scientific findings. Patrick Michael’s (a US climatologist) and Frederick Sykes not only challenged the science but also made unreasonable ad hominem attacks on a number of prominent scientists, including Santer, and claimed such scientists were fraudulent in their approach. From this point, the IPCC were politically in the limelight. This for Peter was the start of climate deniers attempting to derail progress. Their modus operandi was to spread confusion by cherry picking results, targeting prominent scientists and making unsubstantiated claims.
At the end of 1997, parties met in Kyoto (COP3). Attempts at voluntary CO2 emissions had been unsuccessful and Kyoto was to attempt (eventually with some success) to reach a binding international agreement based on the principle of ‘common but differentiated responsibilities’ (i.e. long-term polluters bear the biggest responsibilities). The intention was to be the first step of increasing commitments to CO2 reductions. Yet again attempts were made by deniers to disrupt things. Fred Singer, an American physicist and head of a large lobbying group (Science and Environmental Review; a policy project financed ultimately by the Unification Church) claimed environmental threats were manufactured by corrupt dishonest scientists who could not be trusted. Singer’s group worked with other climate deniers such as Patrick Michaels and Frederick Seitz, founder of the George C Marshall Institute, another denial group. The 1997 Kyoto protocol was the first jointly signed agreement by participating countries to agree to reduce emissions.
Between COP meetings, the climate showed relentless warming. The European heatwave of 2003 showed the effects of global heating (see Fig. 3). Peer review analysis suggest 70,000 died and France was especially hard hit. It was the hottest Summer since 1540 and temperature records in Europe go back many centuries.
Fig. 3 The 2003 European heat wave showing temperature anomalies
After the IPCC’s second report of 1996, revealing stronger links between human activity and climate change than its report 5 years’ previously, there was desire by many countries to reduce greenhouse gases. But the political landscape had changed, George W Bush had been elected US president and likewise, Vladimir Putin occupied the top spot in Russia. Neither were enthusiastic supporters of climate action. Putin in particular felt it amounted to an act of war to prevent Russia developing economically.
However, for Kyoto to be ratified, a majority of participating countries was required and this needed Russian support. A meeting was therefore organised in Moscow in 2004 at the Russian Academy of Science, to discuss this matter further. Established scientists were invited, but so too were notable deniers such as Richard Lindzen (who believed that high level cirrus clouds would dissipate with warming therefore resetting the climate), and Australian, William Kininmonth, a meteorologist whose views were contrary to the scientific consensus. Also present was Swede, Nil-Axel Morner who believed the sea level was not rising together together with general contrarian, Piers Corbyn. Piers Corbyn, an astrophysicist graduate and previously a weather forecaster, claims climate change is due to the solar changes and can predict climate change by a secret technique (an amalgam of past climate data, solar observations and Sun-Earth magnetic anomalies) a method which has not been demonstrated by scientific research. Corbyn is also a proponent of conspiracy theories relating to COVID-19 vaccines.
The agenda and scientific head of the meeting were disruptively changed at the last minute. Prominence was given to deniers over and above established scientists. Most appallingly, Paul Reiter claimed that IPCC scientists were like researchers supporting the use of eugenics as a means of discrimination in Nazi German. Lindzen quoted Goebbels (that if you repeat a lie often enough, people will believe it) directing this comment at IPCC scientists and accused them of being corrupt liars.
Russia eventually signed the Kyoto protocol after the EU dropped objections to them joining the World Trade Organisation and it took effect in 2004. However, damage to an honest, evidence led approach had been done.
The Paris 2007 meeting, approving the IPCC 4th Report, concluded that warming is unequivocal. It was an extraordinary conference. Peter felt it was the best attended conference by scientists and everyone was taking note. There was a general feeling that 1.5 - 2C of temperature increase was manageable.
Despite Kyoto being a valid first step, more was required and further agreements were optimistically envisaged. The year 2009 was the Copenhagen meeting (COP15) where it was hoped more progress could be made. The weather in Copenhagen was particularly poor, failing perhaps to impress attenders that global warming was actually happening. At one point, things looked positive with Barack Obama and Chinese premier, We Jiabao, about to sign a new climate change treaty, but talks collapsed amid poor organisation and distrust between nations. An accord of sorts was agreed (non-legally binding) and no real targets were set on emissions. A few weeks before the meeting, Phil Jones of the climate research unit at University of East Anglia, a notable climate researcher, was targeted and a cache of emails stolen. Deniers accused Jones of fraud and deception (a claim supported by the Daily Express) and lobby groups hoped the publicity from this breach would disrupt the conference. Later independent investigation show there was no fraud.
In January 2012, in Dunalley, Tasmania, a region noted for its mild climate, a highly anomalous temperature of 41.7C appeared out of the blue with extensive forest fires. A notable image from the fires showed the traumatised Holmes family retreating to a safer abode. Australia, like many parts of the world is already an extreme environment and if any more extreme it will be impossible for humans to exist. Parts of the planet will be excluded from human habitation.
Paris 2015 (COP21) was very well executed. The French hosts had performed effective diplomacy before and during the conference and attenders agreed a protocol which limits temperature change of ‘well below 2 degrees or less’, but ideally, no more than 1.5 degrees. 195 countries agreed NDC’s (Nationally Determined Contributions) on emissions reductions.
In 2020, there was more extreme weather with, for the first time, a temperature of 38C above that Arctic circle, and a gradual warming of the normally frozen lands of Siberia. Likewise, in 2021, there were extensive fires in Greece, again an impossible occurrence without global warming.
COP 26 occurred in Glasgow in 2021. Peter was in the science pavilion, immediately available to present science to leaders. A Glasgow Climate Pact was established, with 6 points and that countries will need to ratify every 12 months.
Peter recommends the website https://www.carbonbrief.org for good quality, objective climate information. Such briefings convinced Boris Johnson that climate warming was a genuine problem requiring immediate action.
The Way Forward
Peter discussed the way forward in dealing with the climate emergency with the audience. Immediate action is required to phase out coal burning. We cannot
afford powerful leaders promoting denial and nor those with difficulty in translating aspirational statements into much needed action.
The Montreal protocol of the 1987 was a very positive case study, yet to be replicated, in how the world can come together, to act with focussed determination, to prevent a climate catastrophe, in this case the destruction of the ozone layer by CFC’s (which for reference are also significant greenhouse gases).
Ireland had an interesting approach to climate change through Citizens’ Assemblies, established in 2016 by the Irish Government, to consider contentious issues and make recommendations. The issue of relevance was how to make Ireland a world leader in climate change. Ninety-nine individuals, representative of the demographic, carefully sifted through evidence over a two year period and reached a consensus as to how the government should respond.
Concern was raised that the burgeoning global population was never mentioned as a significant contributory cause of CO2 emissions. Peter admitted this was a difficult subject and the question was often sidestepped by scientists. It has ethical dilemmas, problems of getting people out of poverty and that a developing world is reflected in smaller families. There is behind the scenes concern regarding this problem.
The contribution of methane from cattle farming and rice paddies was raised. Methane is a powerful greenhouse gas and contributes 16% of radiative forcing. It is a much more potent greenhouse gas than CO2, though remains in the atmosphere for a much shorter time (approx. 10 years). 60% of atmospheric methane comes from anthropogenic sources (e.g. cattle farming, rice paddy fields and landfills). A clear message here was for better diets for cattle and a need to eat less meat.
In 2019, the UK legislated to meet net zero emissions by 2050, by greater use renewable energy, decarbonising of heating of buildings etc. A rarely mentioned aspect of net zero is that to stabilise carbon levels, atmospheric CO2 capture and storage by technological means will be required. Such technology is trumpeted by policy makers as a panacea but the practical reality is that it has not been successfully demonstrated on anything like the scale required to be effective. Peter noted that Myles Allen sensibly advocates that oil industry experts are the best group of people to lead this technology.
The influence of broadcasters such as the BBC was mentioned. There had been a criticised approach by the broadcaster of giving equal weight to both established scientists and deniers. A review into impartiality and accuracy was conducted by geneticist, Steve Jones. He warned against this false balance and that the BBC should avoid giving equal weight to consensus and minority views.
The value of publicity from Greta Thunberg and Extinction Rebellion was queried. Greta, Peter thought, is certainly inspiring to younger people though her dismissal of the proceedings at Glasgow was unhelpful. Likewise, Extinction Rebellion may have a reasonable position but its means of fomenting ’rebellion’ are contentious. Citizen power though is a very important tool in achieving climate change. Motivations of deniers were considered. Some appeared to be genuine contrarians, others have vested interests and some based their views on interpretations of the free market.
The last, and probably the most important question is: how long do we have left? Peter felt that the U.K. was doing well reducing emissions. China and India, representing 18 and 17.5% of the world population respectively, needed to come on board. Peter felt that China was moving in the right direction, but India was of concern. India’s energy minister, Raj Kumar Singh pointed out in 2021 that it is unfair for developing nations to be prevented from developing in the name of climate change.
For those interested in the science and history of climate change, Peter has written a book, ‘Hot Air: The Inside Story of the Battle Against Climate Change Denial’, Atlantic Books, London ISBN: 978 1 83895 248 8. Also of note is ‘Geographical, Special Issue, Cop26: Our Best Last Chance’ The people, the science, the politics that can save us’, November 2021, The Royal Geographical Society.
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