Tuesday, August 07, 2012

US abandons 2ºC target? No, but it's still almost impossible under current assumptions

UPDATE: It seems my original headline and intro jumped the gun, at least on official US policy, relying on a secondhand and partial reading of the speech in question. My apologies. The rest of the post still holds and the paralysis of the US political system remains one of the largest roadblocks to any reasonable climate outcome.

The Obama administration has now abandoned the one piece of significant agreement to have come out of seventeen rounds of international climate negotiations, namely, the idea that the world was committed to aiming to keep warming below 2ºC. This temperature rise refers to the global average surface temperature's rise above pre-industrial levels* and covers a wide range of actual average temperature changes (and an even wider range of changes in temperature extremes) in various locations.
*Some documents use other baselines, such as the "climatological period" i.e. 1950-80, or even more recent periods of three decades. It is important to note whether a given temperature rise is based on pre-industrial baseline or a more recent one. Since temperatures rose by around 0.5ºC between the pre-industrial period and 1950-80 (and more since then), then discussions of future rises need to be adjusted accordingly. International negotiations have generally used the pre-industrial period as a baseline, even though the precise global temperature figures are a little sketchier.

The idea that 2ºC is a "safe" guardrail has a complex history, but it is fair to say that more recent climate science has shifted our understanding of just how dangerous 2ºC is. The expected impacts that were thought to arrive at 2ºC back when it was first established as something of a de facto line in the sand between safe and dangerous climate change are now expected to arrive much sooner, at somewhere between 1 and 1.5ºC. So if the developing consensus ten or fifteen years ago was that impacts associated with 2ºC were a valid danger limit, then really, if we are going to be honest and keep our judgements about what is dangerous, we ought to think that anything much above 1ºC is dangerous.

Unfortunately, going well beyond 1ºC is already guaranteed due to inertia in the climate system. What the US has now publicly acknowledged is what has been widely known for years - that inertia in the political and economic system has rendered 2ºC impossible within current economic and political assumptions.**
**The extent to which decades of failure from US leadership on this issue has rendered such a target politically impossible ought not to be underestimated. Despite featuring prominently in his campaign and inauguration, since coming into office, Obama has barely mentioned it and now puts out ads in support of coal.

To this, I say, "so much the worse for those assumptions". But the status quo would not be the status quo if it didn't try to protect itself from having to change. Unfortunately, climate change by definition rules out the possibility of no change. Our current trajectory is inherently unsutainable, which doesn't mean that polar bears are threatened by it, it simply means it will be not be sustained. Something must give. I would rather that be our political and economic assumptions than the habitability of the planet for as many generations as we can imagine.

We are on track for 4ºC if all nations stick to their current aspirational targets, and something more like 6ºC on our current trajectory, according to the normally conservative IEA. Professor Kevin Anderson, director of the Tyndall Centre for Climate Change in Britain, says that a rise of four degrees would likely be "incompatible with organized global community, is likely to be beyond 'adaptation', is devastating to the majority of ecosystems and has a high probability of not being stable (i.e. 4°C would be an interim temperature on the way to a much higher equilibrium level)." No one really knows what six degrees would mean, though sober-minder scientists start discussing human extinction as more than a theoretical possibility.

So, who's happy with six degrees? No takers? What about four degrees? Professor Hans Joachim Schellnhuber, Chair of the German Scientific Advisory Council, advisor to the German Chancellor Angela Merkel and Director of the Potsdam Institute for Climate Impact Research (PIK) was quoted back in March 2009, saying that on a four degree world the planet’s "carrying capacity estimates [are] below one billion people." So, who's happy to retain our present political and economic assumptions that make 2ºC seem impossible?

Basically, even with our best efforts, on the most optimistic path possible, we are in serious trouble. Facing these realities means shock, grief, fear, anger, guilt and feelings of helplessness. But until we face our situation honestly, we're living a lie. So let us be honest, grieve and then find reasons to fight even a losing battle.


byron smith said...

The Bulletin: A conspiracy of silence.

"The consequence of this inattention is an irreversible commitment to dangerous climate change. Twenty years ago, the United States signed, and the Senate ratified, the United Nations Framework Convention on Climate Change. The objective of this treaty was to "prevent dangerous anthropogenic interference with the climate system," which was defined in the Copenhagen Accord of 2009 as limiting the overall temperature increase to 2 degrees Celsius. There are three reasons why that goal is now unobtainable. First, even if greenhouse gas concentrations in the atmosphere could be held steady at 2005 levels, scientists at the Scripps Institution of Oceanography have calculated that global temperature would rise by 2.4 degrees Celsius if not for the air pollution that is masking the warming by blocking some of the sun's rays. Second, as a 2011 paper by British climate researchers explains, emissions reductions that are constrained to levels thought to be compatible with economic growth are not sufficient to stay below 2 degrees Celsius. Only a period of planned austerity and an intensive effort to build a carbon-free energy system could now achieve the goal of avoiding dangerous climate change. Finally, the International Energy Agency has estimated that the carbon-emitting energy infrastructure that will push global temperature rise beyond 2 degrees Celsius is already 80 percent complete, and will be fully installed by 2017. This will lock in future emissions unless capital equipment is retired earlier than anticipated. The best we can now hope for is to avoid catastrophic global warming in excess of 4 degrees Celsius, which will require an aggressive response by governments around the world."

byron smith said...

(PS This article is from the guys who run the Doomsday Clock.)

byron smith said...

Vancouver Sun: EU criticises US U-turn.

byron smith said...

Here is the full text of the speech by US Special Envoy for Climate Change Todd Stern.

byron smith said...

CP: US does not abandon 2ºC target. Oops - looks like I jumped the gun (along with a few others).