Climate change animations from global climate models

Contact: John Walsh (jwalsh@iarc.uaf.edu)

These animations show the types of changes temperature, precipitation and sea ice predicted by global climate models. The simulations cover the period from the present to the year 2100, and summarize the output from five leading climate models (two in the U.S., and one each from Canada, the U.K. and Germany).. These are the same models that were used in the Arctic Climate Impact Assessment, so they provide the basis for inferences about changes in arctic vegetation, ecosystems, permafrost, marine access and various other climate-related activities of humans. The animations depict averages of the simulations by the five models; an animation of any single model’s output would have sharper features in space and time.

The first animation shows the month-by-month changes of surface temperature. The yellow and red colors denote warming relative to the present, while green and blue denote cooling. During the first few decades, the transient and spotty patterns of cooling warming illustrate the natural variability that is characteristic of our present climate. However, by the middle and especially the late 21st century, the dominance of warming (yellows, reds) is apparent. The Arctic is generally 3 to 6 degrees C warmer by the end of the century, according to these models.

The second animation shows the same type of 21st-century evolution, but for changes of precipitation. In this case, green and blue denote wetter conditions than at present, while yellow denotes drier. Although precipitation is a “noisy” quantity (i.e., it varies substantially with location and over time), the animation shows a trend toward wetter conditions in the Arctic. In particular, the more frequent occurrence of deep blue (very wet) features points to the likelihood of increased flooding events in northern high latitudes by the end of the century.

The third and fourth animations show the models’ projected sea ice cover through the year 2100. The color-coding represents ice concentration, i.e., fractional ice coverage. The ice retreat is more rapid in summer (September, right panel) than in winter (March, left panel), as little sea ice is projected to remain in September by 2100.

Finally, the last animation shows the observed temperature variations over the past several decades. The color-coding is the same as in the first animation (temperatures from models). In the case of the observational date, some areas have no data and are left blank in the animation. Nevertheless, a tendency for the warmer colors to predominate in the past two decades is evidence of the recent warming trend in the Arctic.

1. Surface air temperature from a Five GCM Composite from 1980 and projeceted through the year 2099

2. Precipitation from Five GCM Composite from 1980 and projected through the year 2099

3. Surface air temperature from a Five GCM Composite showing January 1980 to December 2099

4. Sea ice from a Five GCM Composite showing years 2000 to 2099