Several recent reports have pointed out that without significant, immediate action to lower global warming emissions, we are getting dangerously close to blowing past emissions levels that would lead to a 2°C or more increase in global temperatures. That may lead some to think that the 2°C benchmark is becoming increasingly irrelevant, but nothing could be further from the truth.
The growing risk that we may reach 2°C is an ever more urgent reminder that we must make swift, deep emissions reductions and invest in building resilience to the worsening climate impacts that we are locking in.
This is a moment for sober stock-taking (i.e. not the usual passing-the-buck, gratuitous finger-pointing, or creative emissions accounting — all of which are currently much in evidence at the UNFCCC negotiations underway in Doha) of why we’ve failed to act despite the very real risks of climate change that are even now starting to affect millions of people. And it provides a renewed sense of urgency that we must take all prudent steps to keep future temperature increases as low as possible. To do otherwise would be risking the health and well-being of people and our planet now and in the future.
Why the 2°C goal matters
The 2°C goal for climate action has been broadly endorsed by the world’s leaders, first at the G8 summit in Aquila in July 2009 and then later by a much larger group of countries at the Copenhagen climate talks in December 2009. (Several countries have endorsed an even lower target of 1.5°C, including the small island states, and most African countries and other least developed countries, which are and will be most seriously affected by climate change.)
In some sense, from a scientific point of view, the exact numeric target has always been an arbitrary choice. The relationship between atmospheric greenhouse gas concentrations and temperature increases is a probabilistic one. Global temperature increases occur on a continuum over time and their impacts often play out over even longer time scales. There’s no magic “stop button” at 2°C. But scientists have warned about the growing dangers as we get close to 2°C and go beyond it. One of the most riveting portrayals of this is the familiar “burning embers” graphic.
So what 2°C represents is a policy consensus informed by climate science. Accepting that goal was supposed to motivate programs of deep emissions reductions around the world that would help fulfill it and thereby help lessen some of the worst consequences of climate change.
Why the prospects of staying below 2°C look so grim
In a nutshell, the reason we are failing so far to meet our global goal is a complete and utter lack of political will and sense of urgency in major emitting countries. It seems fruitless to point fingers at individual major emitting countries when the fact is that none are doing what they need to do. The stalemate at Doha only further highlights this (although I still hold out hope for a breakthrough in the final hours of the negotiations).
We have the technologies and know the policies that are needed to deliver deep emissions reductions. That is definitely NOT what’s held us back. We know that because we’ve seen several of them adopted around the world, just not at the scale and speed at which we need them to come online.
Why it is all the more urgent that we take all prudent steps to limit further temperature increases
Of course, it is of foremost importance that we put pressure on our political leaders to live up to their promise to limit global temperature increases to no more than 2°C. But if they fail to deliver, let’s remember that climate impacts and risks only increase (in non-linear and sometimes irreversible ways) with temperature increases so it is still important to limit those increases as much as possible. We have to double down, not give up!
Here in the U.S. the political prospects for comprehensive climate and energy legislation seem dim, but nevertheless this call to action from scientists and economists to U.S. policymakers is as relevant today as the day it was first rele