Two-Degree Target Insufficient to Stop Global Warming

The scientist who first pointed out that global warming is a real phenomenon is now saying that the 2-degree warming target that we should strive to avoid is insufficient to prevent climate change. It is widely believed that warming needs to be kept under 2 degrees Celsius in order for the Earth to be safe.

Reaching this target is nearly impossible at this point, primarily because the political will to do so is lacking, and the fact that oil and coal companies and their leaders still have more power than certain governments. Still, even if the will to avoid disaster existed, more action should be aimed for.

Experts meeting in Durban, South Africa, to discuss global warming and solutions to avoid climate change are operating even now under the assumption that keeping warming under 2 degrees Celsius would safeguard the planet form extreme climate swings.

However, the director of the NASA Goddard Institute for Space Studies, in New York, believes that this target is unfeasible for avoiding these changes. James Hansen explains that international climate negotiators are now operating under the wrong assumptions.

Some of the most troublesome issues affecting the world today – such as sea level rise, the melting of ice sheets and the release of methane stored in permafrost – can be avoided only if atmospheric carbon dioxide concentrations are kept below 350 parts per million (ppm).

Today, these concentrations reach 389 ppm, and continue to rise. This year also saw global carbon emissions exceed 10 billion tons for the first time, so things appear to be getting worse, not better.

Hansen first raised the issue of reducing CO2 emissions in the United States during Senate hearings held back in 1988, The Independent reports. He was also one of the first to propose limiting fossil fuel burning throughout the country, and later the world.

“The target of 2C […] is a prescription for long-term disaster. You can't say exactly what long term is but we are beginning to see signs of slow [climate] feedbacks beginning to come into play,” he added.

Such feedback loops are visible in the Arctic, where ice continues to melt at a largely self-sustained pace. This happens because meltwater is blacker than seawater, which allows it to capture more sunlight, in turn melting even more ice.

Another feedback loop is visible in the case of carbon trapped in permafrost in the form of methane. Warmer temperatures lead to the release of methane, but methane increases temperatures even further, so that more of the carbon compound gets released.

“We should be aiming to keep CO2 no higher than about 350ppm and possibly somewhat less. That is probably necessary if we want to maintain stable ice sheets and shorelines and avoid many other issues,” the Goddard investigator said at the fall meeting of the American Geophysical Union.

“If we want to maintain a planet that looks like the one humanity has known, then we're basically out of time. We have got to start reducing emissions, but this continued rapid growth [in emissions] makes it exceedingly difficult,” he concluded.