Capping Climate Change: The Making of the Two Degree Celsius Target

On December 12, 2015, a conference hall in Paris erupted with applause. In the middle of an unusually warm December, world leaders hashed out a climate deal some twenty years in the making.

Pictured at the COP21 Final Ceremony (from left to right): Christiana Figueres, Executive Secretary of the UN Framework Convention on Climate Change, Ban Ki Moon, Secretary General of the UN, Laurent Fabius, Foreign Minister of France, Francois Hollande, President of France. Pictured at the COP21 Final Ceremony (from left to right): Christiana Figueres, Executive Secretary of the UN Framework Convention on Climate Change, Ban Ki Moon, Secretary General of the UN, Laurent Fabius, Foreign Minister of France, Francois Hollande, President of France.

After two tumultuous weeks of negotiating (just before the end of the warmest year on record), delegates from 195 countries reached what the New York Times has hailed as a “landmark climate accord.” The Paris Climate Agreement, for the first time in the history of climate policy, mandates that every signatory nation lower greenhouse gas emissions, the infamous atmospheric disruptors. The accord sets a firm ceiling of 2 degrees Celsius (above preindustrial levels) on global average temperature rise and calls for more ambitious efforts to constrain warming to 1.5 degrees. The pact itself certainly merits attention (and has received its fair share), but what I hope to unearth in this post is just how these numbers have been conjured and made their way into the political spotlight.

One might suspect that the latest climate science and modelling have generated the two degree limit, bolstering it with the weight of impartial authority. It isn’t an unreasonable assumption, especially given the diligent efforts made under the UN climate policy process to maximize science-policy translation. It isn’t entirely inaccurate, either: the two degree limit was first proposed by scientific advisers in the early 1990’s as a way to maintain the more or less stable climatic conditions that had prevailed for the past 12,000 years. Two degrees Celsius was seen as the maximum permissible temperature increase within which climate would not reel into a state never before witnessed (much less adapted to) in human history.

Boasting a properly scientific genesis, the threshold soon gained political traction. In 2009, the two degree objective was enshrined in the much-anticipated Copenhagen Accord, this time cast as a “tipping point” whose transgression would constitute “dangerous” human interference in the climate system. Its inclusion in the Copenhagen Accord granted the two degree limit an almost irrefutable status.

Depicting two degrees temperature rise as the boundary line between safe and “dangerous” human interference, however, grossly simplifies the uneven patterns in climate change when observed across the globe over time. The threshold’s elegant spareness has made it a political focal point: simplicity equals actionability, the thinking goes. But the target is more symbolically than materially significant, and it brushes over very real concerns about climate change not by promising bold and decisive action but by advancing the illusion of a global consensus purportedly guided by airtight scientific advising.

Just how do climate scientists feel about the two degree cap? After all, it is climate science research that supposedly buttresses this temperature accounting. In truth, many scientists and analysts have all but completely abandoned the two degree limit, dismissing it as the stuff of fantasy rather than a serious and achievable political aspiration. Indeed, the most recent report put out by the Intergovernmental Panel on Climate Change (IPCC) – a body that periodically synthesizes and summarizes the latest scientific literature on climate change for policymakers – casts the two degree target as quixotic. The report quantifies a global “carbon budget” which demonstrates the political will needed to keep temperature rise under two degrees. According to the report, if emissions continue at their present rate the budget will be exceeded in just thirty years. Dishearteningly, leaders all but disregarded the climate budget, and scientists’ recommendations to design policy in accordance with this metric, at the Paris climate negotiations. Although the Paris agreement reasserts the two degree goal, it outlines no concrete allocation mechanisms by which emissions are to be regulated within the global carbon budget, rendering the prospect of a two degree or less rise in temperatures far-fetched.

Noting this disjuncture, renowned climate scientist and advocate James Hansen of the Columbia University Earth Institute calls the Paris Agreement a “fraud,” claiming that the vague terms of the accord do not match the urgent portrait painted by contemporary climate science. Interestingly, Hansen and other scientists question the “safety” of the two degree world altogether. In a recent paper, Hansen and 16 colleagues showed that Earth’s major ice sheets are melting more rapidly than expected, making even two degrees rise a perilous gamble. More to the point, there are a host of planetary feedback loops and amplification effects (such as the relationship between extreme weather and Arctic warming) which further complicate the climate narrative. In short, climate science and projections are themselves characterized by a great deal of uncertainty.

Now, some good news to end a rather bleak blog entry: many scientists and activists are working tirelessly to square climate politics with the latest findings from climate science. Andrew Jordan, of the Tyndall Centre for Climate Change Research in England, suggests that now is the time to “re-think the climate policy narrative.” Rethinking the climate policy narrative could many mean things, of course, but for activists from small island states on the frontlines of sea level rise, it has come to signify stressing the urgency and differential impacts of climate change. At the Paris climate conference, advocates from small island states pushed leaders to lower the temperature rise objective to 1.5 degrees celsius, a precautionary goal with tremendous stakes. This target is a breath of fresh air. It moves in step with the projections of the latest climate science, boldly calling for the deep social and political change necessary to live with/in the calamity unfolding.

"1.5 Degrees" in white neon is lit on the Eiffel Tower in the French capital, as the COP21 United Nations Climate Change Conference takes place at Le Bourget, on the outskirts of Paris, on December 11, 2015. World powers led a frenetic final push on December 11 to seal a UN accord aimed at averting catastrophic climate change, as sleep-deprived envoys battled in Paris over trillion-dollar disputes blocking a deal. / AFP / PATRICK KOVARIK (Photo credit should read PATRICK KOVARIK/AFP/Getty Images)


Peer edited by Mejs Hasan & Nuvan Rathnayaka

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