This figure shows that the global air temperature at the EarthΓÇÖs surface has increased about one-half degree Celsius during the past century. These data were gathered from about 2000 locations around the world. Points on the blue line indicate the differences between the annual temperature averages and the 1951-1980
30-year average. The large jumps between points on this line show that average temperatures vary widely from year to year. Overall, however, average air temperatures at the EarthΓÇÖs surface have increased.
The red line was plotted as a 5-year ΓÇ£running averageΓÇ¥ to smooth out annual jumps and highlight the overall trend. The running average is obtained by averaging the temperatures for a 5-year period.
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The warming trend indicated in the graph is important because it provides physical evidence in support of the predictions of climate models, which indicate that an increase in atmospheric carbon dioxide would cause a rise in global temperatures.
Further scientific investigations and satellite-based observations planned as part of the ESE/EOS Program will advance the understanding of global warming processes and help to provide the predictive capability needed to assess future changes in surface air temperature and the global climate.
One very important aspect of greenhouse investigations has been the development of models for global climate change studies as well as predictions. So far, these models indicate a warming trend that is mostly a by-product of human intervention. There is an important need to further develop and verify the climate models through acquisition, assembly, and analysis of reliable climate data in order to monitor and predict our effect on the planet. The Earth Observing System allows the collection of highly accurate and long-term data sets toward that end.
