Small island nations are calling for an agreement at the U.N. climate summit that will see a mean global temperature increase of just 1.5°C.
Credit: John Pickrell
Will it take some a mega-catastrophe that kills hundreds of thousands, or even millions, before governments take climate change seriously?
The nations of the world can't even come to a binding agreement on how to take steps that would keep global warming from exceeding an average of 2°C, a target preferred by developed countries. But there's plenty of evidence that even this will not be enough to avert disaster.
Two degrees doesn't sound like an awful lot, but it comes into perspective when you consider that global mean temperatures during some parts of the last Ice Age were just 5°C cooler than today. That difference was enough to smother most of North America, Europe and Asia in sheets of ice so thick that they deformed the planet's crust.
The world has already seen an increase of nearly 0.8°C since pre-industrial times, and the impacts are evident from the farmlands of Australia, to the frigid wastes of the Arctic and from the peaks of the Himalayas to the ocean depths.
According to environmental group the World Wildlife Fund (WWF), a 2 to 3°C rise in temperature we will see water shortages for up to three billion people, caused by droughts and melting glaciers.
The world will also see flooding affecting 180 million people in low-lying and coastal regions, and the complete loss of many islands; famines affecting 400 million people; a loss of biodiversity numbering 35% of terrestrial species; and the loss of the majority of coral reefs by 2050.
These reefs protect the coastlines of low-lying nations such as the Seychelles and Maldives, large parts of which are less than two metres above sea level. With no reefs for protection, wave action may sweep them away; even before sea level rises - caused by thermal expansion of seawater, along with melting glaciers and ice caps - plunge them below the water line.
In November 2009, a report from the Environmental Justice Foundation suggested that by 2050, the world could also find itself having to cope with 150 million climate refugees - a possibility grimly illustrated by sculptures of refugees, knee-deep in channels of water, outside Copenhagen's Bella Centre, where the U.N.'s Climate Change summit is being held.
The threat we face from climate change is unparalleled in the history of human civilisation, and that is why continuing questions over the science of global warming are morally reprehensible.
Several weeks ago, hackers broke into computers at the Climate Research Unit (CRU) at Britain's University of East Anglia and stole 13 years' worth of emails. A selection of them - which show CRU scientists in a bad light - were posted on anti-climate change websites, raising questions about the conduct of researchers who play a role in collecting climate data for the top U.N. body, the Intergovernmental Panel on Climate Change (IPCC).
This was leapt upon by climate critics - along with and the delegates from oil-rich Saudi Arabia - who argued that it invalidated much of the science behind global warming.
Some commentators have suggested that the hacking was part of a well-financed and well-coordinated smear campaign aimed at derailling a Copenhagen agreement - and there are even hints that the Russian secret service was behind it.
Since the hacker's handiwork was posted on the Internet - conveniently, just before the Copenhagen meeting - it has become obvious that the messages were taken out of context. But that is, in any case, beside the point.
The evidence that global warming is real, and that it is almost entirely caused by man-made emissions of greenhouse gasses, is based on the work of many thousands of scientists across the planet, in many countries, and employed by hundreds of independent institutions. To ignore this truly vast body of work, relying on thousands upon thousands of separate data sets that all point in the same direction, is patently absurd.
Every major scientific society in the world backs the evidence for global warming. Data published this week by the World Meteorological Organisation (independently corroborated from three large but distinct data sets) shows that 2009 is likely to be the fifth warmest year ever recorded. The first decade of the 21st century is now the warmest decade since weather data was first collected in 1860.
Rajendra Pachauri, the chairman of the U.N.'s Intergovernmental Panel on Climate Change, was forced to defend the science this week in Copenhagen. He told reporters that more than 450 individual scientists contributed to the IPCC's Fourth Assessment Report - the major document that has compiled data on the consequences of global warming - and that, in turn, this research was reviewed by another 2,500 academics.
A statement defending the "professional integrity" of climate science was also circulated by Britain's Met Office, and signed by 1,700 of the nation's top researchers. It reads: "the evidence and the science are deep and extensive. They come from decades of painstaking and meticulous research, by many thousands of scientists across the world who adhere to the highest levels of professional integrity."
To doubt global warming is real is rapidly becoming akin to doubting that HIV is responsible for AIDS, to doubting that the diversification of life is driven by evolution through natural selection, or even doubting that the Earth goes round the Sun.
This is why the governments of the world need to rise above irritating distractions and take deep and meaningful actions that will mitigate catastrophe.
Hurricane Katrina, which caused devastation in the United States in September 2005, is said to have had a catalysed action on climate change. One expert on the negotiations at the Copenhagen summit told me that he fears that, despite the evidence, it's going to be one of the 'three Cs' - "calamity, catastrophe or collapse" - that drives governments to take serious steps to reverse our emissions of greenhouse gasses.
Unfortunately it's going to be people in some of the world's poorest nations - many in Africa and the Pacific - who will bear the brunt of the problem. It is the delegates from those nations who are most desperate for a meaningful political agreement at the end of next week in Copenhagen - and it is they who are demanding an agreement that sees temperature rises capped at 1.5°C or less.
John Pickrell, the deputy editor of Cosmos, is in Copenhagen reporting on the United Nations Climate Change Conference.
