Chapter 2
History of climate change
Scientists predict that if we continue on our current carbon emissions pathway we could warm the planet by between 1.5°C and 4.7°C in the next 80 years, which economists suggest could cost us as much as 20% of world gross domestic product (GDP). In the face of such a threat, it is crucial to understand the history of climate change and the evidence that supports it. The essential science of climate change was all there in the late 1950s, but it was not taken seriously until the late 1980s. Since then climate change has emerged as one of the biggest scientific and political issues facing humanity.
An old science
The history of climate change science is a long one and can be said to have started in 1856 when Eunice Newton Foote (American scientist, inventor, and women’s rights campaigner) published her paper demonstrating the greenhouse effect of CO2. She used glass cylinders and mercury thermometers, and showed that when they were filled with different gases and placed in direct sunlight, the one containing CO2 trapped the most heat. Looking to the history of the Earth, Foote theorized: ‘An atmosphere of that gas would give to our Earth a higher temperature.’
Just three years later, John Tyndall, professor of natural philosophy at the Royal Institution in London, demonstrated and measured the greenhouse effects of different gases. Using apparatus that utilized thermopile technology, he was the first to correctly measure the relative infrared (heat) absorption of gases such as nitrogen, oxygen, water vapour, CO2, CH4, and ozone. He concluded that water vapour is the strongest absorber of radiant heat in the atmosphere and is the principal gas controlling the air temperature of the Earth.
Building on the prior work of scientists such as Tyndall, Joseph Fourier, and Claude Pouillet, in 1896 the Swedish physical chemist Svante Arrhenius calculated how much the Earth’s temperature would change given variations in GHGs. He estimated that a halving of atmospheric CO2 would drop the Earth’s temperature by 4°C, and that this may have been a key cause of the ice ages, while a doubling of CO2 would increase the global temperature by 4°C. He concluded that anthropogenic CO2 emissions resulting from the burning of fossil fuels would be great enough to cause global warming.
But it wasn’t until 1938 that the engineer and inventor Guy Stewart Callendar compiled 147 temperature records from around the world covering the previous 50 years and showed that the world was indeed warming (Figure 7). By using the few atmospheric CO2 measurements available he was able to suggest that a doubling of atmospheric CO2 would cause a 2°C warming, half the figure suggested by Arrhenius. Callendar’s results were initially met with scepticism, but his papers, published through the 1940s and 1950s, prompted other scientists to investigate changes in atmospheric CO2 and what was controlling them.
7. Guy Callendar’s 1938 global temperature compilation.
The Second World War saw a massive improvement in technology, including the development of infrared spectroscopy, and soon after the war scientists were able to show that CO2 in the upper atmosphere at low pressure did absorb heat—thus demonstrating the greenhouse effect. The worry about possible global warming was ignored at first as scientists argued that the oceans would simply absorb any extra anthropogenic CO2 emitted. Roger Revelle, director of the Scripps Institute of Oceanography in California, was concerned by this dismissal. Through his studies of surface ocean chemistry, he found that oceans return much of the CO2 that they absorb back into the atmosphere. This was a great revelation, and showed that because of the peculiarities of ocean chemistry, the oceans would not be the complete sink for anthropogenic CO2 as first thought. We now know that the oceans are taking up about one-quarter of the annual total anthropogenic production (Figure 6).
Charles Keeling, who was hired by Revelle, made the next important step forward in climate change science. In the late 1950s and early 1960s, Keeling used the most modern technology available to measure the concentration of atmospheric CO2 in the Antarctica and Mauna Loa. The resulting Keeling CO2 curves have continued to climb ominously each year since his first measurement in 1958 and have become one of the major iconic images illustrating global warming (Figure 4).
Why the delay in recognizing climate change?
In 1959, the physicist Gilbert Plass published an article in Scientific American declaring that the world’s temperature would rise by 3°C by the end of the century. The magazine editors published an accompanying photograph of coal smoke belching from factories and the caption read, ‘Man upsets the balance of natural processes by adding billions of tons of carbon dioxide to the atmosphere each year.’ This resembles thousands of magazine articles, television news items, and documentaries that we have all seen since the late 1980s. So why was there a delay between the science of global warming being accepted in the late 1950s and the realization by those outside the scientific community of the true threat of global warming at the beginning of the 21st century?
The key reasons for the delay in recognizing climate change were the lack of increase in global temperatures and the lack of global environmental awareness. The global mean temperature (GMT) data set is calculated by compiling all the available land and sea temperatures. From 1940 until the mid-1970s, the global temperature curve seems to have had a slight downward trend (Figure 8). This provoked many scientists to discuss whether the Earth was entering the next great ice age. Increasing knowledge of past climates in the 1970s and 1980s showed that this was highly unlikely, as ice ages take thousands of years to form.
8. Variation of the Earth’s surface temperature over the last 150 years.
Even so, it was not until the late 1980s, when the global annual mean temperature curve started to rise, that the global cooling scenario was finally discarded. By the late 1980s, the global annual mean temperature curve was rising so steeply that all the earlier evidence from the late 1950s and 1960s was dusted off and the global warming theory came to prominence. In fact, it was in 1988 that Professor Jim Hansen, the director of the NASA Goddard Institute for Space Studies, was asked to testify on the matter before the US Senate Committee on Energy and Natural Resources. He stated that, ‘Global warming has reached a level such that we can ascribe with a high degree of confidence a cause and effect relationship between the greenhouse effect and observed warming…It is already happening now.’ This testimony was widely reported by the media, and global warming became a mainstream issue.
It seems, then, that the eventual recognition of climate change was driven by the upturn in the global annual mean temperature. The latest IPCC 2021 science report has reviewed and synthesized a wide range of data sets. It shows that the trend in global temperature first recognized in the late 1980s is correct, and that this warming trend has continued unstopped until the present day (see Figure 8).
The upturn in the recorded global annual mean temperature was not the sole reason for the new prominence of the global warming issue. In the late 1970s and 1980s, there were significant advances in global climate modelling. These new atmosphere–ocean general circulation models (AOGCMs) produced estimates of significant warming associated with a doubling of CO2 in the atmosphere—closer in fact to Arrhenius’s original calculations. By the 1980s, scientific concern had emerged about CH4 and other non-CO2 GHGs, as well as the role of the oceans as a carrier of heat. GCMs continued to improve, and the numbers of scientific teams working on such models increased over the 1980s and the 1990s. In 1992, a first overall comparison of results from fourteen GCMs was undertaken; the results were all in rough overall agreement, confirming that rising GHGs would cause significant global warming.
The rise of the global environmental social movement
The 1980s saw a massive grass-roots expansion in the environmental movement, particularly in the USA, Canada, and the UK, partly as a backlash against the right-wing governments of the 1980s and the expansion of the consumer economy; and partly because of the increasing number of environment-related stories in the media. This heralded a new era of global environmental awareness and the emergence of transnational NGOs. The roots of this growing environmental awareness can be traced back to a number of key markers: these include the publication of Rachel Carson’s Silent Spring in 1962; the image of Earth seen from the Moon in 1969; the Club of Rome’s 1972 report on Limits to Growth; the Three Mile Island nuclear reactor accident in 1979; the nuclear accident at Chernobyl in 1986; and the Exxon Valdez oil spillage in 1989 (although the latter three created environmental problems that were all regional in effect, limited geographically to the specific areas in which they occurred).
It was the discovery in 1985 by the British Antarctic Survey of the depletion of ozone over Antarctica that demonstrated the global connectivity of our environment. The ozone ‘hole’ also had a tangible international cause—the use of chlorofluorocarbons (CFCs)—which led to a whole new area of politics: the international management of the environment. There followed a set of key agreements: the 1985 Vienna Convention for the Protection of the Ozone Layer; the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer; and the 1990 London and 1992 Copenhagen Adjustments and Amendments to the Protocol. These have been held up as examples of successful environmental diplomacy.
These new global environmental concerns and the ability to deal with them internationally were encouraged and articulated by leading politicians of the time. Margaret Thatcher, the prime minster of the UK in 1989, gave an address to the UN outlining the science of climate change, the threat it posed to all nations, and the action needed to avert the crisis. She summed up by saying, ‘We should work through this great organisation and its agencies to secure world-wide agreements on ways to cope with the effects of climate change, the thinning of the ozone layer, and the loss of precious species.’ George Bush Senior, president of the USA, gave similar speeches, including one in 1992 when he outlined his clear skies and global climate change initiatives at the National Oceanic and Atmospheric Administration.
The IPCC was set up in 1988 and produced its very first science report in 1990. Two years later, with the support of leaders from all around the world, the UN held the Rio Earth Summit, officially called the United Nations Conference on Environment and Development (UNCED), to help member states cooperate on sustainability and protecting the world’s environment. The summit was a huge success and led to the Rio Declaration on Environment and Development, the local sustainability initiative called Agenda 21, and Forest Principles. It also set up the United Nations Convention to Combat Desertification, the Convention on Biological Diversity, and the UNFCCC that underlies the negotiations to limit global GHG emissions. The Rio Earth Summit also laid the foundations for the Millennium Development Goals and the subsequent Sustainable Development Goals.
The economists wade in
Economists have been involved with studying climate change from the very beginning of the IPCC process. Two particular publications from economists have had very different effects on the climate change debate. First, there was the publication of the controversial book The Skeptical Environmentalist by Bjørn Lomborg in English in 2001. In this and subsequent publications, he argues that the cost of cutting global GHG emissions is extremely high and that those who suffer most are the poorest, so instead we should alleviate poverty by rapidly developing poor countries.
There are two major issues with this approach. First, the costs of switching to a low-carbon economy are relatively low and may even benefit economic growth. Second, it is deeply unrealistic to expect that rich nations will transfer funds to poorer countries on the scale needed to alleviate poverty just to avoid having to cut GHG emissions.
The second major landmark was the publication of the UK government-commissioned, 2006 Stern Report on The Economics of Climate Change (published in 2007). The report was led by Sir Nicholas Stern, then-adviser to the UK government on the economics of climate change and development, reporting to Prime Minister Tony Blair. The report states that if we do nothing, the impacts of climate change could cost between 5% and 20% of world GDP every year. That means the whole world loses one-fifth of what it earns to address the impacts (discussed in Chapter 5).
This of course puts climate change impacts on a completely different economic scale than was envisaged by Lomborg. But the Stern Report does present some good news, arguing that if we do everything we can to reduce global GHG emissions and ensure we adapt to the coming effects of climate change, this will cost us only 1% of world GDP every year.
The Stern Report was criticized by other economists—for example, does it use the right inherent discount rate? The inherent discount rate is the rate economists use to take into account that consumption inherently has a lower value in the future than in the present. In other words, future consumption should be discounted simply because it takes place in the future and people generally prefer the present to the future. The Nobel Laureate William Nordhaus used inherent discount rates of up to 3%, arguing that people today value an environmental benefit that will occur 25 years in the future half as much as they value having that same benefit today.
Nordhaus, however, has recently come under intense criticism as he claims a 4°C increase in global temperature over pre-industrial levels would only reduce GDP per capita by between 2% and 4%. But the fundamental flaw in Nordhaus’ model is that he uses a linear not a quadratic damage function—so even catastrophic levels of climate change do not do much economic damage in this economic model. The Stern Report has also been criticized for being overly optimistic about the costs of adapting to a low-carbon world. In June 2008, Stern did revise his estimated costs up to 2% of world GDP. Nevertheless, the Stern Report sent seismic waves around the world. It was as if people said to themselves, ‘If the economists are worried about the cost of climate change, it must be real.’
This was not the end of the involvement of economists in climate change and there have been a number of highly influential books and papers which question our whole understanding of economics and its relationship with the environment. These include the economist Tim Jackson’s book Prosperity without Growth, first published in 2009, that challenges the orthodox view that economic growth is required or even desirable. In 2017, economist Kate Raworth published Doughnut Economics, in which she shows seven ways ‘classical economics’ has got it wrong, arguing that environmental limits and basic human rights must be at the centre of economics. For the first time for two generations classical economics is under sustained attack from a new generation of dynamic innovative 21st-century economists who see environmental and human wellbeing as integral parts of the world economy. At the centre of this is how we deal with climate change while improving peoples’ lives.
Climate change and the media
The other reason for the emergence of climate change as a major global issue was the intense media interest. This is because climate change is perfect for the media: a dramatic story about the end of the world as we know it with key protagonists arguing that it is not even real. The majority of newspaper articles in the UK, the USA, and Australia in the 1990s cast doubt on the claims of climate change. There was a recurrent attempt to promote mistrust in science, through strategies of generalization, of exaggerating disagreement within the scientific community, and, most importantly, discrediting scientists and scientific institutions.
There are two possible explanations for this extraordinarily media-facilitated public scientific debate. First, climate change deniers and industrial lobby groups who do not want to see political action to address climate change are using this debate about methods and scientific uncertainty as a convenient hook on which to hang their case for delay. In fact it has been found that in 2019, five of the largest publicly listed oil companies spent over $200 million lobbying to control, delay, or block binding climate policy.
Second, the media’s ethical commitment to balanced reporting, inappropriately applied, draws unwarranted attention to critical views when they are marginal and outside the realm of what is normally considered ‘good’ science. In the UK, the BBC came under increasing criticism for continually presenting this false balance, usually pitching a climate scientist against a seasoned politician or a paid lobbyist.
Beyond conventional media, the so-called debate about climate change has moved on to social media, with climate change deniers attacking the evidence and views of scientists whenever they can. This rise of fake news has impacted many areas of science, including vaccinations and efforts to tackle Covid-19 as well as climate change. Together, false balance in media debate, fake news, and social media campaigns contribute to a public impression that the science of climate change is ‘contested’, despite what many would argue is an overwhelming scientific case that climate change is occurring and that human activity is its main driver.
But things are changing and in the past few years in many countries opinion polls have shown that the majority of the public have realized that climate change is real and a major threat. This is mainly through people’s own experience or watching the effects of extreme weather around the world. There are now regular news stories about climate change, and they continued even during the recent Covid-19 pandemic. Major documentaries such as Al Gore’s An Inconvenient Truth, David Attenborough’s A Life on Our Planet, and BBC1’s Climate Change: The Facts have also drawn widespread attention to the issue.
The new global environmental social movements
In 2008 and 2009, there was a second global rise in social awareness of climate change. This time it was focused on the hope of a major climate deal at the Copenhagen climate conferences. The Copenhagen conference ended in abject failure due to a lack of international leadership, sabotage by the US, and global worries about dealing with the 2008 global financial crash. It took until the Paris 2015 climate conference to get the negotiation back on track. For almost ten years the environmental movement was held back due to the focus on the global economy. This all changed in 2018, when the third wave of the global environmental social movement began.
In May 2018, the protest group Extinction Rebellion was set up in the UK and launched in October 2018 with over a hundred academics calling for action on climate change. The aim of Extinction Rebellion is to use non-violent civil disobedience to compel governments around the world to avoid tipping points in the climate system and biodiversity loss to prevent both social and ecological collapse. In November 2018 and April 2019, they brought central London to a standstill, and Extinction Rebellion’s membership has now spread to at least sixty other cities around the world.
In August 2018, the 15-year-old Greta Thunberg started to spend her school days outside the Swedish parliament holding a sign saying Skolstrejk för klimatet (School strike for climate), calling for stronger action on climate change. The message spread. Soon other students all around the world started similar school strikes once a month on a Friday, and they called the movement ‘Fridays for Future’. It has been estimated that by the end of 2019 there had been over 4,500 strikes across over 150 countries, involving 4 million schoolchildren.
In 2018 and 2019, three extremely influential IPCC reports were published. The first, in 2018, was the Special Report on Global Warming of 1.5°C, which documented what the world needed to do if global temperature rise was to be kept at only 1.5°C. It also showed the positive and negative interactions of climate change mitigation and the sustainability development goals. The second was the Special Report on the Land, on how climate change would impact desertification, land management, food security, and terrestrial ecosystems. The third was the IPCC Special Report on the Ocean and Cryosphere, showing the impacts of climate change reflected in the speed of melting of ice sheets, mountain glaciers, and sea ice, and their implications for sea-level rise and marine ecosystems.
This new social movement and the very latest science inspired many corporations to take a leading role. Microsoft has set the agenda for the technology sector with the ambitious target to go carbon negative by 2030. By 2050, they want to remove all the carbon pollution from the atmosphere that they and their supply chain have emitted since the founding of the company in 1975. Sky has set the agenda for the media sector, pledging that they and their supply chain will go carbon negative by 2030. BP has also declared that it will be carbon neutral by 2050 by eliminating or offsetting over 415 million tons of carbon emissions. These companies form part of a group of over 1,000 global companies that have pledged to adopt science-based targets. Science-based targets effectively mean they will all be at net zero carbon emissions by 2050.
Given all this pressure, governments around the world in 2019 started to declare that we are, in fact, in a climate emergency, and that action has to be taken. At the time of publication, over 1,400 local governments and over 35 countries have made climate emergency declarations. Despite the fact that in 2020 the whole world was focused on dealing with the Covid-19 pandemic, climate change has remained a major issue. There have been lots of debates in the media and on social media about how the world could rebuild the post-Covid-19 economy in a more sustainable and low-carbon way. Many of the suggested ideas are discussed in Chapter 9 and many have already been implemented.