Together the United States, China, the European Union and India are responsible for nearly half of all global emissions. What people forget – conveniently – is that these very countries are the ones that supply the world with their cars, refrigerators, televisions and just about everything else. If you want to help cut carbon emissions, then stop using their products!
Have a little patience, Dear Reader; I have a better idea. Limiting warming to no more than two degrees has become the target for global climate policy. But there are serious questions about whether policymakers can keep temperature rise below the limit, and what happens if they don’t. You might ask: where did the two-degree target come from, and how has it ended up guiding international climate policy?
In the 1970s, the idea that temperature could be used to guide society’s response to climate change was proposed by an economist, Yale professor William Nordhaus, who suggested that warming of more than two degrees would push the climate beyond the limits humans were familiar with.
“According to most sources the range of variation between distinct climatic regimes is on the order of around 5°C, and at present time the global climate is at the high end of this range. If there were global temperatures more than 2°C or 3°C above the current average temperature, this would take the climate outside of the range of observations which have been made over the last several hundred thousand years.” Note that Nordhaus wrote: “Above the current average temperature.”
More than a decade later, in 1988, NASA professor Jim Hansen gave the issue of climate change a boost, linking greenhouse gas emissions to global warming in a testimony to the US Congress. He was one of the first scientists to publicly state that rising emissions could have a dangerous impact. He concluded that the earth was warmer in 1988 than ever before, that human-caused emissions were responsible for the warming, and that temperatures were likely to continue to rise, increasing the likelihood of extreme weather events.
But Hansen didn’t offer Congress a definition of what constituted dangerous climate change.
Looking at the potential impacts of rising greenhouse gas emissions, the Stockholm Environment Institute discussed a number of ways for scientists to measure the world’s efforts to limit climate change. They suggested curbing sea level rise or restricting the concentration of carbon dioxide in the atmosphere as two options. Another was to use global warming as a guide for where to set an overarching limit.
Based on scientific understanding at the time, SEI suggested that to avoid the worst impacts of climate change, a limit should be set at two degrees. But, the report warned, the higher the temperature rise, the bigger the risks from climate change.
“Temperature increases beyond 1.0°C may elicit rapid, unpredictable, and non-linear responses that could lead to extensive ecosystem damage,” the report said, suggesting there is nothing necessarily “safe” about a two degree limit.
Soon after the institute’s intervention, the idea of a two degrees limit started to appear in more mainstream political settings. In 1992, world leaders signed the United Nations Framework Convention on Climate Change at the Earth Summit in Rio de Janeiro. Article 2 of the convention commits countries to stabilising “greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system” but stopped short of defining the level at which climate change became “dangerous” despite growing calls for two degrees of warming to be set as a limit.
Then, in 1996, the European Council of environment ministers became the first political body to lend formal support when it declared, “global average temperatures should not exceed two degrees above pre-industrial levels.”
This was, as far as I know, the first time that a benchmark from which the rise of two degrees Celsius was to be measured. It was not 1996, or even today; it was “above pre-industrial levels” which is quite a different matter.
A year later, 193 countries signed the world’s first binding agreement to cut emissions, the Kyoto Protocol, that set limits on countries’ emissions, taking into account their historical contribution to climate change and their ability to implement policies with the aim of cutting global emissions five per cent on 1990 levels by 2012, the expiration date of the protocol. Actually, the Kyoto Protocol does not even mention the two degrees goal. In 2005, with the treaty ratified by almost 160 countries, the protocol formally came into force. It was hamstrung, however, by the absence of the world’s largest historical emitters, among them the US.
The two degrees limit was a particular point of contention for US diplomats. At the G8 summit in 2008, they reportedly removed references to two degrees from a draft summit conclusion proposed by Germany’s Chancellor Merkel, which set the tone for the next five years of international climate negotiations.
In 2009, attention turned to trying to agree a new deal to replace the Kyoto Protocol. Negotiators hoped the deal would put binding obligations to cut emissions on all the world’s major emitters, including the US and China. The Copenhagen Conference failed miserably despite headlines such as “Climate change has been caused over centuries, has consequences that will endure for all time and our prospects of taming it will be determined in the next 14 days.”
The newspapers went on: “The science is complex but the facts are clear. The world needs to take steps to limit temperature rises to 2°C, an aim that will require global emissions to peak and begin falling within the next 5-10 years. A bigger rise of 3-4°C – the smallest increase we can prudently expect to follow inaction – would parch continents, turning farmland into desert. Half of all species could become extinct, untold millions of people would be displaced, whole nations drowned by the sea.”
Such media reports were immensely misleading. The whole world was led to believe that the issue was a two degrees rise in global temperatures above today’s temperatures, which is entirely false!
At the Cancun meeting in 2010, countries signed agreements committing governments to “hold the increase in global average temperature below 2°C above pre-industrial levels” that is the levels prior to the Industrial Revolution.
The Industrial Revolution was the transition to new manufacturing processes in the period from about 1760 to sometime between 1820 and 1840. It was a time of immense innovation. Without the strides made in manufacturing, transport and commerce during this revolution, we would still be living in a world of poverty, disease and despair, which does not mean there are not still those who have not benefitted.
It seems unlikely that the two degrees target will simply fade away post-2015. But the limit may find itself under pressure in a world that has to start adapting to warming rather than just seeking to avoid it.
The official target of the United Nations Framework Convention on Climate Change (UNFCCC) is that to avoid serious climate change, global mean temperature rise should not exceed 2°C above pre-industrial levels.
The research shows carbon dioxide emissions increased from 6.1 billion tonnes in 1990 to 9.5 billion tonnes in 2011 – an increase of 25 per cent. The rate of increase is growing too – from 1.9 percent per year in the 1980s to 3.1 per cent per year since 2000. The researchers estimate emissions in 2012 will be 2.6 per cent above 2011 levels, 58 per cent higher than in 1990.
A less ambitious scenario suggests that the two degrees could be hit without negative emissions, relying instead on changes in fuel use and energy efficiency. The UK, Denmark and the US have had several periods since the 1970s in which they reduced emissions by one to two per cent per year by substituting gas for coal or oil. Belgium, France and Sweden reduced emissions by 4-5 per cent over a ten year period by moving from oil to nuclear.
Finally, the average global temperature increased by 0.8% since 1880. Two thirds of that warming took place between 1975 and the present day. So we only have an additional 1.2 degrees to go!
Despite this, some say, “Two degrees is still within reach if we can muster the political will,” while others chip in, “staying below two degrees is unlikely but not impossible,” and even suggest that it is possible to limit additional warming to 1.5 degrees Celsius.
Emerging technologies are being developed to permanently remove carbon dioxide from the atmosphere – resulting in negative emissions. Such technologies could include carbon capture and storage (CCS) from fossil fuels and biomass. Relying on negative emissions is risky, however, because it depends on the large-scale roll out of emerging, untried and untested CCS technologies on a large scale. For my part, I believe that the next revolution will entail the harvesting of greenhouse gases from the atmosphere. I have no idea how they will do it, but Greed being a great motivator, I am sure once someone sees a profit in it, a new industry will be born.
But be warned: If we mess with negative emissions by harvesting carbon dioxide and other greenhouse gases from the atmosphere and allowing unfettered radiation heat loss, we could plunge the world into a new ice age. Now wouldn’t that be ironic!