The outcome of the recent UN climate change conference, in Cancun, Mexico, was a disappointing one. Expectations had been very low to begin with, especially following the catastrophic failure of the previous conference in Copenhagen in December 2009. At the conference, countries agreed to limit the global temperature rise to 2 degrees Celsius above pre-industrial levels. However, the target is not legally binding and global temperatures are already 0.8 degrees Celsius above pre-industrial levels.
The Cancun agreement reinforces the pledge made by rich countries in Copenhagen in 2009 to give $100 billion per year in aid to developing countries by 2020. However, it is still not clear how the aid will be funded. It was also decided to pay developing countries to protect their forests. This is actually a very good idea. Timber logging and the clearing of forest land are both extremely profitable and a major source of carbon emissions. If the monetary reward for protecting forests becomes greater than the reward for destroying them, many of the remaining forests could be saved. Again, however, no one knows where the money will come from.
Many at the Cancun summit, particularly from richer countries seemed to be unaware of how perilously close we might be to irreversibly destroying our planet. Scientists are now finding that the Earth could be heating faster than we previously realised. There is compelling evidence that once global temperatures rise to 2 degrees Celsius above pre-industrial levels, our planet will pass a tipping point. From then on, the planet will heat up all by itself, due to positive feedback mechanisms, in a process known as “runaway climate change”.
One positive feedback mechanism involves the oceans’ ability to store CO₂. The world’s oceans absorb and store about a third of all the carbon humans emit. However, warmer water is less effective at storing CO₂. As the oceans heat up, they will take in less and less CO₂ and might actually start releasing it back into the atmosphere, thus changing from a carbon sink into a carbon source. This release of carbon will make the planet (and the oceans) even warmer, causing the oceans to release more CO₂, and so on.
Positive feedback may also happen as global warming triggers the sudden release of greenhouse gases that have been trapped for thousands of years. In Siberia, a vast area of frozen peat-land known as the “permafrost” is beginning to thaw. The frozen bog is the size of France and Germany combined and scientists believe huge amounts of methane, a greenhouse gas 20 times more powerful than CO₂, currently trapped beneath the ice will be released as the permafrost melts. There may also be frozen crystals of methane at the bottom of many of the world’s oceans, which could be released as ocean temperatures rise.
Another positive feedback mechanism is the albedo effect. White surfaces reflect more solar radiation than dark surfaces. As the polar ice caps melt, they leave behind dark ocean, which takes in more heat, helping the remaining ice to melt faster, and so on.
The effects of climate change are already being felt around the world. 2010 was the hottest year on record and extreme weather events including flash floods, hurricanes, heat waves and droughts have all become more common and more severe. Those of us who were in UCC last year saw the effects of global warming ourselves when the river Lee burst its banks and flooded large parts of the city, including buildings in the university. If there hadn’t been a dam on the Lee at Inniscarra, the flooding would have been much worse.
Predictions show that as the planet continues to heat, poorer countries will suffer the most. In some parts of Africa, it is estimated that agricultural yields could be reduced by up to 50% as soon as 2020. In Asia, the Himalayan glaciers are the source of all the continent’s major rivers. Two billion people depend on these rivers for drinking water and irrigation. It is expected that over a billion people will be affected as these glaciers continue to recede.
Our own former president, Mary Robinson, who was at the Cancun conference, said in an interview, “the climate issue is the most compelling human rights issue of the 21st century”. She added, “already, it’s destroying the human rights of a lot of people – the rights to food and safe water. It’s going to be the source of conflicts.” On a positive note, Mrs. Robinson asserted, “what encourages me is that young people get it…they actually know it better than I do.” It is vitally important that decisive action is taken soon to reverse the trend of global warming. We need to curb the rise in greenhouse gas emissions during the next ten years and then drastically reduce them. Let’s hope the negotiators at the next UN climate change conference in Durban, South Africa, can reach a better deal.