2015.10.29 – Global Warming Under MIT Ambition

This post provides supporting information to Fossil Free MIT’s October 29, 2015 opinion article in MIT’s student newspaper, The Tech, entitled ‘MIT’s Climate Plan doesn’t add up. So we’re sitting-in.’ In particular, we here substantiate our statement that “If all developed countries followed MIT’s emissions reduction plan, a simulation run by Climate Interactive projects that global warming would drastically overshoot the 2 °C danger limit, with a most likely temperature rise of 3.4 °C by 2100.” MIT’s emissions reduction plan was announced on October 21, 2015 as part of its Plan for Action on Climate Change and pledges to “reduce campus greenhouse gas emissions 32% by 2030”.

Our statement is based on the results of a climate simulation conducted by researchers at Climate Interactive, a not-for-profit with close ties to MIT. Climate Interactive’s models have their origins in research conducted at MIT and are used by climate negotiators from the United States and numerous other governments.

Climate Interactive
’s simulation asked, “If, like MIT, all developed countries were to adopt an emission reduction target of 32% by 2030 with respect to 2014 baseline emissions (confirmed via personal communication with the MIT administration), and all developing countries adhere to their existing Intended Nationally Determined Contributions (INDCs – each country’s publicly declared commitments to climate action), how many degrees of global warming are projected to occur by 2100?” The simulation was performed using Climate Interactive’s publicly available C-ROADS model, which you can download here to verify the results of this study.

Figure 1. Projected global warming for: (blue) business as usual (RCP8.5); (green) MIT-level ambition, as defined in the text; and (black) a 2 degrees Celsius pathway.

Figure 1. Projected global warming for: (blue) business as usual (RCP8.5); (green) MIT-level ambition, as defined in the text; and (black) a 2 degrees Celsius pathway.

Under these conditions, the simulation finds projected warming by 2100 of 2.0 to 4.5 degrees Celsius, with a most likely temperature rise of 3.4 degrees Celsius. This projected warming trajectory is delineated by the green line in Figure 1 and is shown in comparison to the business as usual scenario (RCP8.5) in blue and a trajectory consistent with holding global warming below 2 degrees Celsius in black (the danger limit agreed to by nearly every country in the world in the 2009 Copenhagen Accord and acknowledged by the MIT Plan for Action on Climate Change as a threshold above which “the resulting damage to societies and natural systems around the world becomes increasingly grave”.

Figure 2 shows the corresponding greenhouse gas emissions trajectories: (blue) under business-as-usual conditions; (green) with MIT-level ambition, as defined above; and (black) consistent with 2 degrees Celsius (black).

emissions1

Figure 2. Annual greenhouse gas emissions trajectories: (blue) under business-as-usual conditions; (green) with MIT-level ambition, as defined in the text; and (black) consistent with 2 degrees Celsius.