CO2 Modeller

Model the effect of carbon emissions reductions on climate change using your smartphone or tablet.

CO2 Modeller is available for Android and iOS devices.

Download it from Google Play and Apple App Store.

CO2 Modeller uses a streamlined computationally efficient Earth system model to simulate the effect of carbon emissions reductions on climate change. It generates twenty-first century projections of atmospheric carbon dioxide concentration and global averages of surface warming, sea level rise and ocean acidification.

An eight-box climate model is used to simulate the carbon cycle in the atmosphere, ocean and terrestrial (soil and vegetation) systems, and the heat uptake by the oceans. In just a few seconds, based on carbon emissions reductions that you choose, CO2 Modeller runs an ensemble of 1000 independent simulations from 1765 to 2100. In these 1000 simulations, the equilibrium climate parameter is varied to match the range seen in state of the art climate models. This allows CO2 Modeller to make a range of illustrative future projections at greatly reduced computational cost on a tablet or smartphone.

Comprehensive climate projections, incorporating simulations from many highly complex state of the art climate models, are publicly available within the Assessment Reports of the Intergovernmental Panel on Climate Change (see www.ipcc.ch).

The outputs of the model are projections to 2100 of atmospheric carbon dioxide concentration and global averages of surface warming, sea level rise and ocean acidification. From the 1000 independent simulations, CO2 Modeller provides both a best estimate of these future trends and also their likely range. The effects of the chosen carbon emissions reductions are compared against a business-as-usual case (based on the IPCC RCP8.5 scenario) for each of the four outputs.

Atmospheric carbon dioxide (CO2) concentration (parts per million - ppm) is the mixing ratio of CO2 in the atmosphere. CO2 Modeller calculates this by simulating the amount of carbon emitted into the atmosphere and the amounts that are subsequently taken up in the terrestrial (soil and vegetation) and ocean systems.

Surface warming (°C) is the global mean warming of surface air temperatures since pre-industrial times (1765). CO2 Modeller calculates this using the atmospheric carbon dioxide concentration (as calculated above)), other atmospheric constituents, and the ocean uptake of heat.

Sea level rise (m) is the rise in global mean sea level relative to the 1986 to 2005 average. CO2 Modeller calculates this using the ocean uptake of heat and surface warming (as calculated above).

Ocean acidification (pH) is the global mean surface ocean pH level. Ocean pH was approximately 8.2 during pre-industrial times. CO2 Modeller calculates pH level by simulating the carbon uptake of the surface ocean.

The climate model that CO2 Modeller uses is based on the Warming Acidification Sea-level Projector (WASP) Earth system model described in [1], with the surface warming calculated as per [2]. To enable CO2 Modeller to generate projections rapidly on tablets and smartphones, WASP has been adapted in a number ways. For full details, see our white paper.

Goodwin, Philip (2015) How historic simulation-observation discrepancy affects future warming projections in a very large model ensemble. Climate Dynamics, Accepted for publication. (Archive)
Goodwin, Philip, Williams, Richard G. and Ridgwell, Andy (2015) Sensitivity of climate to cumulative carbon emissions due to compensation of ocean heat and carbon uptake. Nature Geoscience, 8, p29-34. DOI:10.1038/ngeo2304. (Paper, Archive)

CO2 Modeller is a University of Southampton project supported by in the UK by NERC and EPSRC. To provide feedback, report bugs or request new features, please contact info@co2modeller.info. For news and updates, please follow @co2modeller.