Caldeira Lab Research:Energy, Global Carbon Cycle, and Climate

Future CO2 emissions and climate change from existing energy infrastructure

S. J. Davis, K. Caldeira & H. D. Matthews

We asked a hypothetical question: what if we never built another CO2-emitting device, but the ones already in existence lived out their normal lives? We found that atmospheric concentrations of CO2 would stabilize at less than 430 ppm and the increase of global mean temperatures since preindustrial time would be less than 1.3°C. In light of common benchmarks of 450 ppm and 2°C, these results indicate that the devices whose emissions will cause the worst impacts have yet to be built.

Davis, S. J., K. Caldeira, and H. D. Matthews (2010), Future CO2 emissions and climate change from existing energy infrastructure, Science, Sep 9, 2010, doi:10.1073/pnas.0906974107












Figure: Graph shows projected decline of carbon dioxide emissions in gigatons (billions of tons) from existing energy and transportation infrastructure (red wedge) over the next 50 years, compared to three emissions scenarios (dotted lines) from the Special Report on Emissions Scenarios (SRES) Intergovernmental Panel on Climate Change (IPCC). High, middle, and low emissions projections correspond to the SRES A1G-FI, A2, and B1 scenarios, respectively.


Slowing climate change requires overcoming inertia in political, technological, and geophysical systems. Of these, only geophysical warming commitment has been quantified. We estimated the commitment to future emissions and warming represented by existing carbon dioxide–emitting devices. We calculated cumulative future emissions of 496 (282 to 701) gigatonnes of CO2 from combustion of fossil fuels by existing infrastructure between 2010 and 2060, forcing mean warming of 1.3°C (1.1° to 1.4°C) above the pre-industrial era and atmospheric concentrations of CO2 less than 430 parts per million. Because these conditions would likely avoid many key impacts of climate change, we conclude that sources of the most threatening emissions have yet to be built. However, CO2-emitting infrastructure will expand unless extraordinary efforts are undertaken to develop alternatives.


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