Land surface temperature is like the skin temperature of the Earth—it’s how hot or cold the ground feels to the touch—and it is a key variable that scientists use to study the exchange of energy and water between the land surface and the atmosphere. Land surface temperature is influenced by physical properties like vegetation density and soil moisture.
Global land surface temperature trends
Global land temperature in 2016 was the warmest on record—relative to the 20th century average—with a temperature departure of 2.6°F (1.42°C). This beat 2015's record of 2.4°F (1.32°C). The years 2014 and 2013 were the 6th and 7th warmest on record. These data points are consistent with the dramatic increase in land surface temperatures since 1950 due to global warming.
A July 2014 study finds that human-caused warming had a direct influence on the increasing frequency of hot summers in the Northern Hemisphere since the late 20th century.
Combined land and ocean surface temperature trends
Only seven percent of the heat trapped by greenhouse gases stays near the land surface; the other 93 percent is stored in the ocean. For this reason, the combination of land and ocean surface temperature data is a better indicator of global warming than land surface temperature alone.
Scientists have calculated the globally averaged combined land and ocean surface temperature over the period 1880 to 2012 and found a warming of 1.3°F (0.85°C). Each of the past three decades has been successively warmer at the Earth’s surface than any the previous decades in the instrumental record, and the decade of the 2000’s was the warmest.
Taking into account annual land and ocean surface temperatures, 2016 was the third year in a row with record heat, and scientists say the heat’s primary cause is climate change. In 2016, the annual average temperature across global land and ocean surfaces was 1.67°F (0.93°C) above the 20th century average. Global temperature in 2015 was 1.62°F (0.90°C) above the 20th century average, and in 2014, 1.33°F (0.74°C) above.
US average temperature has increased by 1.3°F to 1.9°F since 1895, and most of this increase has occurred since 1970. The most recent decade was the nation’s and the world’s hottest on record, and 2012 was the hottest year on record in the continental United States. 2016 and 2015 were the second and third hottest years in the US respectively.
All US regions have experienced warming in recent decades, but the extent of warming has not been uniform. In general, temperatures are rising more quickly in the north. Alaskans have experienced some of the largest increases in temperature between 1970 and the present. People living in the Southeast have experienced some of the smallest temperature increases over this period.
An August 2016 attribution study found a “very strong anthropogenic influence” on 2014’s record yearly average temperature in Europe.
A February 2015 study analyzing temperature data in Europe from 1951 to 2010 found that exceptionally hot summers (two standard deviations from the long-term average) occur about twice as often as cold summers, and are characterized by greater temperature anomalies. An October 2010 attribution study found that human activity shifted temperature distributions towards higher values in Europe from 1999 to 2008 in all seasons.
Western Europe in particular has seen a rapid increase in summer (June–August) mean surface air temperature (SAT).
In the eastern portion of the Middle East, long-term temperature trends show consistent warming throughout the region.