Global warming trend continues
February 7, 2019 -- The past five years have been, collectively, the hottest on record, with 2018 the fourth-warmest since modern records began.
In 2018, Earth’s global surface temperatures were the fourth warmest since 1880, according to analyses by NASA and NOAA.
Global temperatures in 2018 were 0.83°C warmer than the 1951 to 1980 mean and 1.01°C warmer than the 1880 mean. Globally, 2018’s temperatures lie behind those of 2016, 2017 and 2015, but collectively, the past five years are the warmest on modern record.
According to scientists, the warming is being driven in large part by increased emissions into the atmosphere of carbon dioxide and other greenhouse gases caused by human activities.
Weather patterns affect regional temperatures, so not every region on Earth has experienced the same amount of warming, but the trend is strongest in the Arctic region, where 2018 saw the continued loss of sea ice. Additionally, mass loss from the Greenland and Antarctic ice sheets continued to contribute to rising sea levels. Increasing temperatures are also contributing to longer fire seasons and some extreme weather events.
NASA’s temperature analyses incorporate surface temperature measurements from 6,300 weather stations, ship- and buoy-based observations of sea surface temperatures, and temperature measurements from Antarctic research stations.
These raw measurements are analyzed using an algorithm that considers the varied spacing of temperature stations around the globe and urban heat island effects that could skew the conclusions. These calculations produce the global average temperature deviations from the baseline period of 1951 to 1980.
NASA estimates that 2018’s global mean change data has a 95 percent certainty level.