Earth is the only planet we know of that can support life. The planet is not too close or too far away from the sun. It lies in a "Goldilocks zone" that is just right — not too hot, not too cold.
The distance from Earth to the sun is one of the most important factors in making Earth habitable. The next closest planet to the sun, Venus, for example, is the hottest planet in the solar system. Temperatures there reach more than 750 degrees Fahrenheit (400 degrees Celsius), while the average temperature on Mars is minus 80 F (minus 60 C).
Earth's atmosphere also plays a vital role in regulating the temperature by providing a blanket of gases that not only protects us from excessive heat and harmful radiation from the sun, but also traps heat rising from the Earth's interior, keeping us warm.
The average temperature on Earth is about 33.6 F (0.9 C), according to NASA. But temperatures vary greatly around the world depending on the time of year, ocean and wind currents and weather conditions. Summers tend to be warmer and winters colder. Also, temperatures tend to be higher near the equator and lower near the poles.
According to the World Meteorological Organization, the coldest place on Earth is Vostok Station in Antarctica, where it reached minus 128.6 F (minus 89.2 C) on July 21, 1983. The coldest inhabited place is Oymyakon, Russia, a small village in Siberia, where it dips down to an average of minus 49 F (minus 45 C) and once hit a low of minus 96.16 F (minus 71 C).
Which location holds the record as the hottest place on Earth is a matter of some contention. El Azizia, Libya, held the top hot spot for 90 years. Temperatures allegedly climbed to 136.4 F (58 C) on Sept. 13, 1922. But the World Meteorological Organization stripped the town southwest of Tripoli of that distinction in 2012. A committee of climate experts from nine countries concluded that the temperature had been documented in error by an inexperienced observer.
So the "new" hottest place on Earth is Greenland Ranch (Furnace Creek) in Death Valley, Calif., where it reached 134 F (56.7 C) on July 10, 1913. But even that distinction depends on what is being measured. Death Valley's record is for the highest air temperature. A higher surface temperature of 159.3 F (70.7 C) was recorded by a Landsat satellite in 2004 and 2005 in the Lut Desert in Iran.
Highest and lowest temperatures by continent
|North America||High: 134 F (56.7 C)||July 10, 1913||Furnace Creek Ranch, Death Valley, Calif.|
|Low: -81.4 F (-63 C)||Feb. 3, 1947||Snag, Yukon Territory, Canada|
|South America||High: 120 F (48.9 C)||Dec. 11, 1905||Rivadavia, Argentina|
|Low: -27 F (-32.8 C)||June 1, 1907||Sarmiento, Argentina|
|Europe||High: 118.4 F (48 C)||July 10, 1977||Athens and Elefsina, Greece|
|Low: -72.6 F (-58.1 C)||Dec. 31, 1978||Ust 'Schugor, Russia|
|Asia||High: 129.2 F (54 C)||June 21, 1942||Tirat Zevi, Israel|
|Low: -90 F (-67.8 C)||
1) Feb. 5, 1892
2) Feb. 6, 1933
1) Verkhoyansk, Russia
2) Oymyakon, Russia
|Africa||High: 131 F (55 C)||July 7, 1931||Kebili, Tunisia|
|Low: -11 F (-23.9 C)||Feb. 11, 1935||Ifrane, Morocco|
|Australia||High: 123 F (50.7 C)||Jan. 2, 1960||Oodnadatta, South Australia|
|Low: -9.4 F (-23 C)||July 21, 1983||Charlotte Pass, New South Wales|
|Antarctica||High: 67.6 F (19.8 C)||Jan. 30, 1982||Signy Research Station, Antarctica|
|Low: -129 F (-89.2 C)||July 21, 1983||Vostok Station, Antarctica|
Rising temps, rising seas
There is considerable uncertainty about how warm Earth will get in the coming decades, as climate change is complex. It depends on a variety of factors, including how quickly the ice melts in the Arctic and Antarctic, how the ocean will respond to warmer temperatures, and how the atmosphere will shift wind directions. Even little changes in solar activity affect Earth's temperature — but climate change is by far the more pressing problem.
The National Oceanic and Atmospheric Administration (NOAA) says average surface temperatures on Earth rose 1.71 degrees Fahrenheit (0.95 degrees Celsius) between 1880 and 2016, and that change is accelerating in recent years. In 2017, 159 nations ratified the Paris Agreement to try to halt the warming at 2.7 degrees F (1.5 degrees C) above Earth's average temperature before the Industrial Age. Given industry's and transportation's reliance on fossil fuels, many studies say that agreement will be difficult to keep to.
For example, a 2017 study in the journal Geophysical Research Letters suggests that Earth's climate will be 1.5 degrees higher as early as 2026. This would happen if the Interdecadal Pacific Oscillation (IPO) fluctuates back to a warm period, instead of its current cool period. (IPO changes similarly to El Niño and La Niña in the Pacific).
In early 2018, the U.S. National Academies released a report called "Thriving on Our Changing Planet: A Decadal Strategy for Earth Observation from Space." The report focused on the importance of satellite observations in gaining information about Earth's climate in the coming years. Some of its suggestions include observatories that can help with forecasting air quality and weather, and others that can look at metrics such as biodiversity change, extreme weather and the ocean's ability to store heat. [10 Climate Change Myths Busted]
— Additional reporting by Elizabeth Howell, Space.com contributor