C-ROADS in Science: Global Action At Rate of U.S. Progress Could Lead Toward Two Degrees

How might the new U.S. EPA pollution rules ripple out to affect global action that reduces future climate risk?

We were happy when Eli Kintisch of Science asked Dr. Lori Siegel and me here at Climate Interactive to use C-ROADS to answer this question in their article, “A Bold Baby Step On Emissions.”

The graphic in Science is below.

The section in Kintisch’s article reads:

If the United States achieves its 17% emissions reduction with help from the new rules, but acts alone in sustaining the reductions over time, the global rise in emissions and temperature will barely flatten compared with business as usual, according to an analysis done for Science by Climate Interactive, a modeling and visualizing firm based in Washington, D.C. (see graphic). If other nations take comparable steps, however, the gains could be much greater, the modeling suggests—raising the chances of holding the future increase in average global temperature below the 2°C threshold many researchers say is advisable.

Note: all the data used to make the graphs in the Science article (plus another six variables that weren’t in the graphs) are posted for use here. Information on the C-ROADS simulation is here. And you can play with the free online version (C-Learn), which can reproduce results below, here.

Of course, like all scenarios, this one required many assumptions, documented here, the most important being:

1. Rules affecting CO₂ emissions from the electricity generation sector would be complemented by others in the U.S. affecting transportation, agriculture, land use, and other industry.
2. Other countries around the world – particularly those growing their economies and energy use much faster than the U.S. – could reduce their emissions at 1.2% year and start immediately.

Ambitious assumptions, indeed. But that is why we are here with Grounded Hope, our next effort which uses a global energy and climate simulation, En-ROADS, to spark global action towards prevention of future climate risk. Join us: info@climateinteractive.org. 

Below we have included our version of the full graph, with concentration levels, 90% confidence intervals, and other information.

For the full spreadsheet, including yearly data for eight output variables (if you would like to make your own graph) click here. A sample is below.