Fact No. 1. The rate of global warming during the past several decades has been about 0.18ºC per decade. There is no evidence that this rate is increasing. If this continues to the end of the 21st century, the temperature increase will be about 1.8ºC. Some fraction of this warming is a result of natural fluctuations in the earth’s climate as well as from other non-greenhouse-related changes (changes in land use, urbanization, industrialization, data quality, etc.); there is evidence that controls on black carbon (soot) pollution could result in less warming. A warming of this magnitude is near the low end of the range of projections issued in 2001 by the U.N.’s Intergovernmental Panel on Climate Change. Associated with a low-end warming are low-end projections of sea-level rise and other types of environmental changes Fact No. 2. During the past several decades, the earth’s vegetation has responded in an overwhelmingly positive fashion to changes in the earth’s climate. On average the growing season has lengthened (primarily by beginning earlier in the spring) and the total plant biomass has increased by about 10 percent. This remarkable growth enhancement has been due both to the fertilization effects of increased atmospheric carbon dioxide as well as the beneficial effects of the patterns of climate change across the globe Fact No. 3. During the past several decades, anthropogenic emissions of carbon dioxide have continued to rise, but the rate of build-up of carbon dioxide in the atmosphere has leveled off. That means that the earth’s biosphere has responded by increasing the rate of carbon dioxide uptake. This is evidenced by Fact No. 2—enhanced global plant growth Fact No. 4. During the past several decades (and more), human technological advances have kept pace with, and in most cases exceeded the rate of climate change—no matter what the cause. For example, in major U.S. cities, where the thermal effects of urbanization are many times larger than the effects of any climate change, the population has become less sensitive to periods of extremely high temperature (heat waves). This is documented through declining heat wave mortality. In fact, today, many U.S. urban areas experience no increases in mortality during heat waves—a situation that was vastly different only 20 to 30 years ago.