Weathercasters in the U.S. not only tend to avoid mentioning climate change, the majority of them do not even believe it is human-caused. However, that may change. The American Meteorological Society (AMS) released an official position statement on climate change this week which not only said that it is occurring, but it is human-caused. What is so great about the statement by the AMS is that it includes so much information about climate change, including a frank statement of the scientific consensus. The AMS makes it clear that the statement is “based on the peer-reviewed scientific literature and is consistent with the vast weight of current scientific understanding.”
The statement details how the climate is changing, both in the U.S. and around the world. The changes listed include increases in globally averaged air and ocean temperatures, the widespread melting of snow and ice, and the rising of globally averaged sea level. As the statement puts it, “Warming of the climate system now is unequivocal, according to many different kinds of evidence.” That is not good news for the world’s population, but it is good news that the AMS is acknowledging that climate change is real and is occurring.
The statement goes in to detail about the effects of climate change, which include temperature increases. All of the 10 warmest years in the global temperature records up to 2011 have occurred since 1997, and 2005 and 2010 were the warmest years in more than a century of global records. Most of the observed warming in the U.S. has occurred in the West and in Alaska, but for the country as a whole there have been twice as many record daily high temperatures compared to record daily low temperatures in the first decade of the 21st century.
The statement also details other changes, including sea level rise, melting ice sheets and precipitation changes:
- Greenland and Antarctic ice sheets “have lost significant amounts of ice,” and most of the world’s glaciers are retreating.
- Heavy precipitation events have increased over the last 50 years through the U.S.
- Freezing levels are rising in elevation, with rain occurring more frequently, and an increase of snow at mid-elevations of western mountains.
- Spring snowpack is decreasing, and snowmelt occurs earlier, while the spring runoff that supplies over two-thirds of the western U.S. streamflow is reduced.
- Globally averaged sea level has risen by about seven inches in the 20th century, and close to half of the sea level rise since the 1970s has been caused by water expansion due to increases in ocean temperatures. Sea level is also rising because of melting from continental glaciers and Greenland and Antarctica ice sheets.
While the statement does acknowledge that “global efforts to slow greenhouse gas emissions have been unsuccessful so far,” it provides some hope. It mentions that if “future technologies and policies” can achieve a “rapid reduction of greenhouse gas emissions…this would greatly lessen future global warming and its impacts.” In other words, the business world and governments need to work together to find ways to decrease GHG emissions.
Photo: Flickr user, globochem3x1minus1