Key Points
- Since 1901, the average surface temperature across the contiguous 48 states has risen at an average rate of 0.16°F per decade (see Figure 1). Average temperatures have risen more quickly since the late 1970s (0.31 to 0.54°F per decade since 1979). Eight of the top 10 warmest years on record for the contiguous 48 states have occurred since 1998, and 2012 and 2016 were the two warmest years on record.
- Worldwide, 2016 was the warmest year on record, 2020 was the second-warmest, and 2011–2020 was the warmest decade on record since thermometer-based observations began. Global average surface temperature has risen at an average rate of 0.17°F per decade since 1901 (see Figure 2), similar to the rate of warming within the contiguous 48 states. Since the late 1970s, however, the United States has warmed faster than the global rate.
- Some parts of the United States have experienced more warming than others (see Figure 3). The North, the West, and Alaska have seen temperatures increase the most, while some parts of the Southeast have experienced little change. Not all of these regional trends are statistically significant, however.
Background
temperature is a fundamental measurement for describing the climate, and the temperature in finical places can have wide-ranging effects on homo life and ecosystems. For example, increases in air temperature can lead to more acute heat waves ( see the Heat Waves indicator ), which can cause illness and death, specially in vulnerable populations. Annual and seasonal worker temperature patterns besides determine the types of animals and plants that can survive in especial locations. Changes in temperature can disrupt a wide range of lifelike processes, particularly if these changes occur more cursorily than plant and animal species can adapt .
Concentrations of heat-trapping greenhouse gases are increasing in the Earth ’ mho atmosphere ( see the Atmospheric Concentrations of Greenhouse Gases indicator ). In response, average temperatures at the Earth ’ second surface are increasing and are expected to continue rising. Because climate change can shift the wind instrument patterns and ocean currents that drive the universe ’ south climate system, some areas are warming more than others, and some have experienced cool .
About the Indicator
This indicator examines U.S. and ball-shaped coat temperature patterns over time. U.S. surface measurements come from upwind stations on land, while global come on measurements besides incorporate observations from buoys and ships on the ocean, thereby providing data from sites spanning much of the open of the Earth. This indicator starts at 1901 except for the detail map of Alaska, where authentic statewide records are available binding to 1925. For comparison, this index besides displays satellite measurements that can be used to estimate the temperature of the Earth ’ s lower atmosphere since 1979 .
This index shows annual anomalies, or differences, compared with the average temperature from 1901 to 2000. For exemplar, an anomaly of +2.0 degrees means the average temperature was 2 degrees higher than the long-run average. Anomalies have been calculated for each weather place. daily temperature measurements at each web site were used to calculate monthly anomalies, which were then averaged to find an annual temperature anomaly for each class. Anomalies for the conterminous 48 states and Alaska have been determined by calculating average anomalies for areas within each state based on station density, interjection, and topography. These regional anomalies are then averaged together in symmetry to their area to develop national results. similarly, ball-shaped anomalies have been determined by dividing the global into a grid, averaging the data for each cell of the grid, and then averaging the grid cells together.
About the Data
Indicator Notes
Data from the early twentieth hundred are slightly less precise than more late datum because there were fewer stations collecting measurements at the time, specially in the Southern Hemisphere. The overall trends are silent authentic, however. Where possible, the data have been adjusted to account for any biases that might be introduced by factors such as station moves, urbanization near the post, changes in measuring instruments, and changes in the exact times at which measurements are taken .
Hawaii and U.S. territories are not included, due to limitations in available data.
Read more: Maritime search and rescue – Documentary
Data Sources
The datum for this indicator were provided by the National Oceanic and Atmospheric Administration ’ s National Centers for Environmental Information, which maintains a bombastic collection of climate data on-line at : www.ncei.noaa.gov. The surface temperature anomalies shown here were calculated based on monthly values from a network of long-run monitor stations. Satellite data were analyzed by two mugwump groups—the Global Hydrology and Climate Center at the University of Alabama in Huntsville ( UAH ) and Remote Sensing Systems ( RSS ) —resulting in slenderly different tendency lines .
Technical Documentation
- Download related technical information PDF
References
1 USGCRP ( U.S. Global Change Research Program ). 2017. Climate science special report : Fourth National Climate Assessment, book I. Wuebbles, D.J., D.W. Fahey, K.A. Hibbard, D.J. Dokken, B.C. Stewart, and T.K. Maycock ( eds. ). hypertext transfer protocol : //science2017.globalchange.gov. doi:10.7930/J0J964J6.
2 NOAA ( National Oceanic and Atmospheric Administration ). 2021. Climate at a glance. Accessed February 2021. www.ncdc.noaa.gov/cag .
3 NOAA ( National Oceanic and Atmospheric Administration ). 2021. Climate at a glance. Accessed February 2021. www.ncdc.noaa.gov/cag .
4 NOAA ( National Oceanic and Atmospheric Administration ). 2021. Climate at a glance. Accessed February 2021. www.ncdc.noaa.gov/cag .
