Global Warming and Extreme Weather: The Science, the Forecast, and the Impacts on America | Environment Michigan
A recent report published by the U.S. National Academy of Sciences stated that “the conclusion that the Earth system is warming and that much of this warming is very likely due to human activities” is “so thoroughly examined and tested, and supported by so many independent observations and results,” that its “likelihood of subsequently being found to be wrong is vanishingly small.”
The national academies of sciences of 13 leading nations issued a joint statement in 2009 stating that “climate change is happening even faster than previously estimated.”
A 2009 study of the work of more than 1,300 climate researchers actively publishing in the field found that 97 to 98 percent of those researchers agree with the central theories behind global warming.
The consequences of global warming are already beginning to be experienced in the United States, and are likely to grow in the years to come, particularly if emissions of global warming pollutants continue unabated.
Average temperature in the United States has increased by more than 2° Fahrenheit over the last 50 years. Temperatures are projected to rise by as much as an additional 7° F to 11° F on average by the end of the century, should emissions of global warming pollutants continue to increase.
The United States has experienced an increase in heavy precipitation events, with the amount of precipitation falling in the top 1 percent of rainfall events increasing by 20 percent over the course of the 20th century. The trend toward extreme precipitation is projected to continue, even as higher temperatures and drier summers increase the risk of drought in much of the country.
Snow cover has decreased over the past three decades in the Northern Hemisphere, and the volume of spring snowpack in the Mountain West and Pacific Northwest has declined significantly since the mid-20th century.
Sea level has risen by nearly 8 inches globally since 1870. Global sea level is currently projected to rise by as much as 2.5 to 6.25 feet by the end of the century if global warming pollution continues unabated. Parts of the northeastern United States could experience an additional 8 inches of sea-level rise due to changes in ocean circulation patterns.