English: Description is based on NOAA (2007) public-domain source: GFDL CM2.1 model-simulated change in seasonal mean surface air temperature from the late 20th century (1971-2000 average) to the middle 21st century (2051-2060). The left panel shows changes for June July August (JJA) seasonal averages, and the right panel shows changes for December January February (DJF). The change is in response to increasing atmospheric concentrations of greenhouse gases and aerosols based on a "middle of the road" estimate of future emissions. Future emissions are based on the "A1B" emissions scenario, taken from the Special Report on Emissions Scenarios. Warming is projected to be larger over continents than oceans, and is largest at high latitudes of the Northern Hemisphere during Northern Hemisphere winter (DJF).

The term “global warming” is commonly used to refer to surface air temperature changes that are a response to increasing atmospheric greenhouse gas (GHG) concentrations. However, the warming is not expected to be uniform over the globe, nor is it expected to be the same during all seasons of the year. Computer model simulations conducted at NOAA’s Geophysical Fluid Dynamics Laboratory (GFDL) and elsewhere project that GHG induced warming will be more rapid over land masses than over oceans. In the image, red colors indicate greater warming over the continents. White and blue-green colors mark areas with the least warming or slight cooling, found mostly over oceans. Additionally, the greatest warming is expected during the winter over northern North America and north-central Asia.

The map on the left of summer (June, July, August JJA) temperatures projects warming of around +1 to +3 °F over most ocean areas, and +1 to +9 over most land areas. The map on the right of winter (December, January, February DJF) temperatures projects greatest warming at polar latitudes, of around +9 to +16 °F. The DJF map also shows warming of around 0 to +3 °F over most of the Pacific and Atlantic oceans.

References:

https://web.archive.org/web/20090506082504/https://www.gfdl.noaa.gov/patterns-of-greenhouse-warming-ar4

NOAA, January 2007: GFDL Climate Modeling Research Highlights: Patterns of greenhouse warming (PDF), vol. 1, no. 6, revision 2/2/2007, 8:50.08 AM. The National Oceanic and Atmospheric Administration (NOAA) Geophysical Fluid Dynamics Laboratory (GFDL) - Princeton, NJ, USA