Climate Conference: ‘We’re at the Tipping Point’
Photo by Claude Oesterreicher
Our planet is on the edge of a series of tipping points that will make it irreversibly hotter, according to scientists from around the world who have been meeting in London this week.
Specific estimates differ but the world’s temperature looks set to rise by six degrees Celsius (approx 10 degrees Fahrenheit) by the end of the century unless drastic measures are taken right now.
As carbon emissions grow, climate change will become irreversible polar ice sheets melt, rainforests dry up, and oceans become more acid.
“We are on the cusp of some big changes,” said Will Steffen, executive director of the Australian National University’s climate change institute. “We can … cap temperature rise at two degrees, or cross the threshold beyond which the system shifts to a much hotter state. This is the critical decade.”
Steffen said that for the polar ice sheets, we’re probably already over the tipping point. And we know that the Amazon rainforest has been losing carbon to the atmosphere at an increasing rate – from 1.6 billion tons in 2005 to 2.2 billion tons in 2010.
One of the things we don’t know, however, is how much carbon will be released into the atmosphere as the Siberian permafrost melts. And this may be the biggest factor of all in the coming years.
“There is about 1,600 billion tons of carbon there,” he said. “About twice the amount in the atmosphere today. And the northern high latitudes are experiencing the most severe temperature change of any part of the planet.”
Discussing the future of the oceans, Carol Turley of the Plymouth Marine Laboratory said that in the past 200 years, ocean acidification has happened at a speed not seen for around 60 million years, and is driving the extinction of species.
Sir John Beddington, science adviser to the British government, said that no one knows how to get the world on a path toward stabilizing carbon dioxide in the atmosphere. He acknowledged that this process will take a very long time and require a series of generational handoffs as we learn more. Such an approach may be too late to halt the spiraling changes, and it has more to do with managing climate change rather than trying to set in place global agreements to stop it.
The Planet Under Pressure conference concluded with a call for urgent action to stem the continuing buildup of greenhouse gases, and was seen, in part, as preparation for the upcoming international meeting in June in Rio de Janeiro, where world leaders will once again try to hammer out some new agreements to turn back the tide of climate change.