Large snowballs melting near COP21

I arrived in Paris just 3 days ago, but my time here at COP21 has been filled, and it seems like a much longer period of time 

Report from Paris: COP21 at the Halfway Point

December 6, 2015

Large snowballs melting near COP21

I arrived in Paris just 3 days ago, but my time here at COP21 has been filled, and it seems like a much longer period of time. I spent Thursday afternoon and evening in various sessions organized by international trade unions and spoke for 45 minutes in one of these, focusing on why unions should oppose shale gas development. The audience of 50 or so union leaders was informed and engaged and very interested in learning the details of our research on how methane emissions make shale gas disastrous for the climate, not a bridge fuel at all. (See howarthlab.org for the smart-phone friendly electronic handout to accompany this presentation and another presentation I will give on Thursday, December 10, in an event on fracking organized by a large number of NGOs.)  I was encouraged to see the dozens of other events with unions on Thursday, with hundreds of participants, pushing for a fossil fuel-free future. We finished the night with a delightful reception in the historic Salle Ambroise union hall in Paris, built in the 1880s.

Robert HowarthHowarth, the David R. Atkinson Professor of Ecology & Environmental Biology at Cornell University, is a member of Cornell's COP21 delegation (watch his COP21 video)

I spent most of Friday at various presentations that were part of COP21 Oceans Day.  A long list of distinguished speakers – scientists, diplomats, and politicians – reiterated how closely the oceans are coupled to climate change:  the oceans are absorbing 25 percent of the carbon dioxide released from burning fossil fuels, but of course this may well change (likely becoming less) as climate change alters the physical circulation of the oceans. Coastal ecosystems dominated by seagrasses, mangroves, and salt marshes probably store additional carbon (“blue carbon,” as opposed to the dirty “brown carbon” released from fossil fuels or the beneficial “green carbon” stored in terrestrial ecosystems); these coastal systems also buffer cities and towns from the worst of storms. On the other side, ocean acidification threatens to greatly affect many marine ecosystems, and coastal communities and nations are among the most vulnerable to the effects of climate change from sea-level rise and intensification of storms. As of last Wednesday, the draft negotiation text for COP21 had a section highlighting the importance of the oceans, but we were told on Friday this text had been dropped as part of the editing to shorten the document that occurred on Thursday. There were many strong calls on Friday to reinstate this text on the oceans. I am not sure how it will play out.

Hundreds of events are occurring each day of COP, many open only to official delegates, but a large number open to all, including some in downtown Paris (COP21 is in Le Bourget, some 15 km from the center of Paris). My favorite is a set of 12 big, jagged chunks of ice placed in front of the Pantheon, in view from my hotel: each of the “glaciers” started out at some 2 m or more in height, but they are rapidly melting in the relatively balmy temperatures of Paris, and many will likely be gone as COP21 comes to an end in five days. The message is clear to the large crowds attracted to these “glaciers.”

The actual climate negotiations are going on behind closed doors. Most of what I know I have learned from the excellent daily briefings put out by the International Council of Science (ICSU). Among the remaining sticking points are these three: who will pay to help developing nations reduce their carbon footprints and mitigate the consequences of global warming, what should be the target temperature for an “acceptable” level of warming, and when should the nations of the world next review progress in meeting the target temperature? As a scientist, I am most interested in these last two points, which are critical and related.

If all countries live up to pledges for emission reductions made leading up to COP21, we are told the planet will warm to 2.7° C. All climate scientists I respect agree that is not an acceptable target, and we need to keep warming below that level if we are to avoid a high risk of global catastrophe, to society as well as to natural ecosystems. The talk before the start of the meeting was that nations might agree to 2° C instead. That’s better, but Jim Hansen and others have argued strongly this is still too much warming, and I certainly agree. The French government has proposed a target of 1.5° C, which is far preferable, and during the first week of COP21, Germany also endorsed this lower target. Of course simply adopting a target does not ensure that the target will be met, which is why France and many other nations are also proposing a reassessment in just another few years. This seems like a very good strategy to me and is likely to be the most we can expect from COP21.

Will the COP actually endorse this 1.5° C target with reassessment in a few years? Many nations oppose this lowering of the target, and as far as I know, the United States has so far been silent on the issue. The next five days will give the world the answer to this question. Let’s hope that the nations of the world can come together over this sensible plan, which is quite modest given the stakes. According to the predetermined strategy for COP21, the French formally took over as the leads for the final negotiation as of the halfway point yesterday. The French government has invested substantial political capital behind COP21, and the tragic terror events of two weeks ago in Paris may help as well, providing sympathy for the French viewpoint.

A point related to these targets, which is so far getting far too little discussion in Paris, is the relative roles of carbon dioxide and methane emissions. Carbon dioxide is the most important gas behind global warming, as virtually everyone knows. But what most people do not grasp is that we will see long lags in the climate-system response to reduced carbon dioxide emissions, when these reductions finally occur. The planet will continue to warm for decades anyway, and certainly reach the 1.5° C target, quite likely in just 12 to 15 years, if the world focuses only on carbon dioxide. The response of the climate to methane is fundamentally different: reductions in emissions now will slow global warming almost immediately, and this offers us one of the only possible routes to staying below 1.5° C of warming. This is the message I am trying to bring to Paris, together with information on the best ways to reduce methane emissions.

It is an exciting time to be in Paris.  Stay tuned.