Science Source

Climate Change Indicators in the United States 2016 - Fourth Edition

Summary of Key Points

7 percent—the increase in US greenhouse gas emissions caused by human activities from 1990 to 2014
7 percent—the decrease in total US greenhouse gas emissions since 2005
35 percent—the increase in worldwide, net emissions of greenhouse gases from human activities from 1990 to 2010
42 percent—the increase in carbon dioxide emissions, which account for about three-fourths of total emissions, from 1990 to 2010
800,000—the number of years compared to which current current global atmospheric concentrations of carbon dioxide are unprecedented, as shown by historical measurements
37 percent—the increase in total warming effect from greenhouse gases added by humans to the Earth’s atmosphere from 1990 to 2015
30 percent—the increase in total warming effect associated with carbon dioxide alone from 1990 to 2015

10 hottest years occurred between 1998 and 2015
0.08 inches—the average rate of increase in precipitation per decade over land areas worldwide since 1901
9 out of 10—the number of top years for extreme one-day precipitation events in the US that have occurred since 1990
20 to 70 percent—US land area experiencing abnormally dry conditions at any given time from 2000 through 2015

0.6 inces—the rate at which global sea level has risen per decades since 1880
8 inches—the increase in sea level registered along the Mid-Atlantic coast and parts of the Gulf coast between 1960 and 2015

September 2012—when scientists measured the lowest annual minimum Arctic sea ice extent as the melt season for Arctic ice grows
24 days—the maximum number of days earlier that thaw dates have shifted among northern lakes in the US over the past 110 years
80 percent—the number of locations studied that saw more winter precipitation fall in the form of rain instead of snow in the US since records began in 1930
3,300 square miles—the average decrease per year in the portion of North America covered by snow between 1972 and 2015
Two weeks—the amount of time shorter that snow covers the ground since 1972 in the US
90 percent—the proportion of measurement sites showing a decrease in early spring snowpack in the western US between 1955 and 2016
23 percent—the average decline in early spring snowpack across all measurement sites in the US between 1955 and 2016

9,000—the number of heat-related deaths reported since 1979 in the US
28,000—the number of heat-related hospitalizations across 20 states from 2001 to 2010
100 percent—the nationwide increase in reported cases of Lyme disease since 1991
10 out of 11—the number of studied locations in the central US and Canada that experienced an increase in the length of ragweed pollen season since 1995

9 out of 10—the number of years with the largest acreage burned due to wildfires that have occurred since 2000 in the US, with records going back to 1983
5 days—the least number of days earlier that US rivers and streams show peak winter-spring runoff compared to the mid-20th century
79 percent—the proportion of measurement sites showing an increase in water temperature in the Chesapeake Bay region from 1960 through 2014
1.2°F—the average temperature increase across all Chesapeake Bay stream measurement sites from 1960 through 2014
2.2°F—the average temperature increase at stream sites in the Chesapeake Bay where the trend was statistically significant from 1960 through 2014
40 miles—the average northward shift of wintering grounds for North American bird species since 1966
10 miles—the shift northward along US coasts of the average center of biomass for 105 marine fish and invertebrate species between 1982 and 2015
20 feet—the average shift deeper of 105 marine fish and invertebrate species between 1982 and 2015
119 miles—the average shift northward of American lobster, black sea bass, and red hake between 1982 and 2015