Hobbies And Interests
Thermometer
Scientists have been interested in learning about the temperature changes of the Earth for centuries, especially after the discovery of the ice age coupled with other dynamic shifts in climate and temperature. According to Audubon.org, scientists bean measuring the temperature as early as the 19th century. AIP.org reports that people simply noted the temperature of the air in locations they happened to live or visit, using a basic thermometer to measure what the climate was like. The different measures were then averaged to a global temperature. The thermometer was widely available, and scientists look back at these records that people from various locations made in order to track the temperature and changes at many locations.
Computer Technologies
Computer systems track the temperature every second of every day in every part of the world. The New Atlantis website reports that no more than 100 weather stations in specific parts of the world would be enough to give scientists accurate readings of the Earth's average temperature. However, many more weather stations exist, with more than 100 stations through the U.S. alone, according to the National Weather Service. The fact that there are so many weather stations allows scientists to record the temperature very accurately, although The New Atlantis reports that the average temperature can be calculated with an uncertainty of only 0.04 degrees Celsius. The numbers recorded from the different weather stations are tabulated and analyzed before coming to an average global temperature reading. Calculations are also in place for dampening the effect of extreme climates such as deserts and the polar caps.
Tracking Past Temperatures
When measuring the temperature of the Earth, scientists commonly use tools to compare past and present. The practice of dendroclimatology uses tree rings as a proxy for measuring the temperature going as far back as 10,000 years in some regions of the Earth. Scientists can look at trees which grow hundreds to thousands of rings before dying for their analysis. Additionally they can look at dead wood as well as wood used in construction. They compare the rings in similar regions to come to far better conclusions about what the temperature may have been because the basic principle holds that trees would show changes in ring development depending on changes in temperature of the Earth over time.
Glaciers
Scientists can go back even further in measuring the temperature of the Earth by using glacier analysis. Glaciers are created by annual snowfalls compacting into ice from the following snowfall. Analysis of these glaciers reveals striations corresponding with yearly changes in the oxygen isotope levels of the Earth. These numbers can accurately determine the Earth's temperature from periods before any other technology was available for temperature measurement and tracking.