Today, the U.S. Environmental Protection Agency (EPA) released the third edition of a report, Climate Change Indicators in the United States. The report pulls together observed data on key measures of our environment, including U.S. and global temperature and precipitation, ocean heat and ocean acidity, sea level, length of growing season, and many others. With 30 indicators that include over 80 maps and graphs showing long-term trends, the report demonstrates that climate change is already affecting our environment and our society.
“These indicators make it clear that climate change is a serious problem and is happening now here in the U.S. and around the world,” said Janet McCabe, acting assistant administrator for EPA’s Office of Air and Radiation. “Everything we do to reduce greenhouse gas emissions and prepare for the changes that are already underway will help us safeguard our children’s future.”
The third edition of the Indicators report, which was last published in 2012, adds additional years of data and four new indicators: Lyme disease, heating and cooling degree days, wildfires, and water level and temperature in the Great Lakes. In addition, the report adds four new features that connect observed data records to local communities and areas of interest, including cherry blossom bloom dates in Washington D.C., timing of ice breakup in two Alaskan rivers, temperature and drought in the Southwest, and land loss along the mid-Atlantic coast.
Consistent with the recently released National Climate Assessment, this report presents clear evidence that the impacts of climate change are already occurring across the United States. The report shows evidence that:
· Average temperatures have risen across the contiguous 48 states since 1901, with an increased rate of warming over the past 30 years. Seven of the top 10 warmest years on record have occurred since 1998.
· Tropical storm activity in the Atlantic Ocean, the Caribbean, and the Gulf of Mexico has increased during the past 20 years.
· Along the U.S. coastline, sea level has risen the most along the Mid-Atlantic coast and parts of the Gulf Coast, where some stations registered increases of more than 8 inches between 1960 and 2013.
· Glaciers have been melting at an accelerated rate over the past decade. The resulting loss of ice has contributed to the observed rise in sea level.
· Every part of the Southwest experienced higher average temperatures between 2000 and 2013 than the long-term average dating back to 1895. Some areas were nearly 2°F warmer than average.
· Since 1983, the United States has had an average of 72,000 recorded wildfires per year. Of the 10 years with the largest acreage burned, nine have occurred since 2000, with many of the largest increases occurring in western states.
· Water levels in most of the Great Lakes have declined in the last few decades.
The report also looks at some of the ways that climate change may affect human health and society using key indicators related to Lyme disease incidence, heat-related deaths, and ragweed pollen season. For example, unusually hot summer temperatures have become more common which can lead to increased risk of heat-related deaths and illness. Warmer temperatures and later fall frosts also allow ragweed plants to produce pollen later into the year, potentially prolonging allergy season for millions of people.
EPA compiles decades of observed data in cooperation with a range of federal government agencies, nongovernmental organizations, universities, and other institutions. The Indicators report focuses on long-term trends for key measures of our environment for which high-quality data exist. Each indicator and the report itself were peer-reviewed by independent experts, and extensive technical documentation accompanies the report.
