Geoengineering: a COP out or a necessity?

Every year, the Conference of the Parties (COP) to the United Nations Framework Convention on Climate Change (UNFCCC), an international environmental treaty with 165 signatories and 197 ratifiers, meet to discuss progress with tackling climate change and setting emission reduction targets. 

The most recent meeting was COP 23 earlier this year in Bonn, Germany, but the roleplay that our class engaged in was a re-enactment of COP 21 in Paris during 2015. This particular meeting was important, as it was the first meeting since the 1997 Kyoto Protocol (COP 3) which set a global legally binding agreement on climate with targets for each country. The Paris Agreement, signed by 195 nations, has a primary objective of keeping global warming from pre-industrial levels this century below 2 degrees Celcius as well as beginning mechanisms to review target achievement progress and provide funding for developing nations to invest in renewables. The emission reduction targets set by individual countries are, however, voluntary and not legally binding. Climate scientist James Hansen even called the entire agreement 'a fraud'.

Irrespective of the targets not being legally binding, a problem encountered during our roleplay was the struggle even to set targets which came close to achieving the 2-degree scenario (2DS). This is mirrored in reality, and it has widely been acknowledged that the targets set under the Paris Agreement would not be sufficient to achieve the 2DS. An even larger shadow has been cast over the ambitions by Donald Trump announcing a withdrawal of the United States from the agreement. A recent Bayesian probabilistic model by Raftery et al. (2017) which incorporates trends in the economy, emissions, and population growth predicts that there is just a 5% chance of remaining under 2 degrees warming by 2100, and just a 1% chance of remaining under 1.5 degrees. The study places the likely warming between 2.0 degrees and 4.9 degrees, with 3.2 degrees as the median.

The IPCC has concluded that to stay below 2 degrees warming, global greenhouse gas (GHG) emissions would need to decrease by 1.3-3.1% per year between 2010 and 2050. For perspective, the crippling 2008 recession only managed to reduce global emissions by 1% for a single year. 

Figure 1: Predicted global mean warming according to current policies in place and pledges under the Paris Agreement. Last updated 13th November 2017. (Source: Climate Action Tracker, 2017).

As discussed in a previous blog post, 2DS models often rely heavily on technologies such as BECCS to an unfeasible extent. The question now is: should other geoengineering methods be introduced as a means of making the 2DS a realistic target, despite side effects and not dealing with other impacts of emissions like ocean acidification? Alternatively, maybe the 2-degree target should be reassessed and shifted to 3-degrees or higher? Maybe, as Roger Pielke Jr. suggests, the 'degree warming' metric needs to be reframed into an easy-to-understand trackable goal like examining the proportion of carbon-free energy used. 

It is clear though that if we are serious about achieving the targets set by the Paris Agreement, it is time to talking about geoengineering.