File:Map of projected global warming across the globe by the 2050s using the IPCC SRES A2 greenhouse gas emissions scenario. Data from CMIP3 (2007).jpg

English: The following description is based on the cited public-domain source: This map shows the average of a set of climate model experiments projecting changes in surface temperature for the period 2050-2059, relative to the period from 1971-1999. Future greenhouse gas emissions were fed into the climate models to project future temperature changes. In this temperature projection, emissions are based on the Intergovernmental Panel on Climate Change's emissions scenario "A2" (see Special Report on Emissions Scenarios for more information on the A2 scenario).

The A2 scenario assumes humans will continue to accelerate the rate at which we emit carbon dioxide. This is consistent with a global economy that continues to rely mainly on coal, oil, and natural gas to meet energy demands. In this scenario, our carbon emission increases steadily from today’s rate of about 9 billion tons per year to about 28 billion tons per year in 2100.

All models project some warming for all regions, with land areas warming more than oceans. The image shows greatest warming in Arctic regions, with warming of around 6 to 9 °F.

Scenario A2 is an emissions projection based on plausible assumptions of how human development might progress over the 21st century. However, because emissions projections depend on the choices people make in the future (e.g., over future efforts on energy efficiency and choices over the use of fossil fuels), climate scientists can’t say with certainty how probable this temperature projection is. Greenhouse gas concentrations may grow at rates that are higher or lower than is projected in scenario A2. Future temperature changes may therefore be larger or smaller than is projected in this map.

Over the last decade, global carbon dioxide emissions have increased at a rate of more than 3 percent per year. If this was to continue into the future, carbon dioxide levels in the atmosphere would exceed the A2 scenario by the end of this century, if not before.

File:Projected global warming over the 21st century using three SRES greenhouse gas emissions scenarios. Data from CMIP3 (2007).png shows projected changes in global mean temperature over the 21st century for three emissions scenarios, including the A2 scenario.