Relative dating methods in archeology
Data from these instruments is used to calculate the average temperatures of different layers of the Earth’s atmosphere.  * The lowermost layer of the atmosphere, which is called the “lower troposphere,” ranges from ground level to about five miles (8 km) high.  According to satellite data correlated and adjusted by the National Space Science and Technology Center at the University of Alabama Huntsville, the average temperature of the lower troposphere increased by 0.60ºF (0.33ºC) between the 1980s and 2000s, mostly from 1997 to 2010: * Sources of uncertainty in satellite-derived temperatures involve variations in satellite orbits, variations in measuring instruments, and variations in the calculations used to translate raw data into temperatures.  * According to temperature measurements taken near the Earth’s surface that are correlated and adjusted by NASA’s Goddard Institute for Space Studies, the Earth’s average temperature warmed by 1.5ºF (0.8ºC) between the 1880s and 2000s, mostly during 1907–19–2014: * According to temperature measurements taken near the Earth’s surface that are correlated and adjusted by the Climatic Research Unit of the University of East Anglia in the U.
K., the Earth’s average temperature warmed by 1.4ºF (0.8ºC) between the 1850s and 2000s, mostly during 1911-19-1998: * Sources of uncertainty in surface temperature data involve “very incomplete” temperature records in the earlier years, “systematic changes in measurement methods,” “calculation and reporting errors,”       data adjustments that are performed when instruments are moved to different locations, instrument precision, instrument positioning, and missing documentation/raw data.  definitive assessment of uncertainties is impossible, because it is always possible that some unknown error has contaminated the data, and no quantitative allowance can be made for such unknowns. * Oceans constitute about 71% of the Earth’s surface. Changes in air temperature over the world’s oceans are typically based on measurements of water temperature at depths varying from less than 3 feet to more than 49 feet.  This data is combined with changes in air temperature over land areas to produce global averages.  contrasted water and air temperature changes in the tropical Pacific Ocean using three sources of measurements.
A caveat of this finding is that the feedback process operates “on a time scale of weeks,” and “it is not obvious whether similar behavior would occur on the longer time scales associated with global warming.”  * Other feedbacks that may have “a substantial impact on the magnitude, the pattern, or the timing of climate warming” include snow coverage, temperature gradients in Earth’s atmosphere, aerosols, trace gases, soil moisture changes, and ocean processes. * Per a 2003 report by the United Nations Food and Agriculture Organization, between the mid-1970s and late 1990s, apparent food consumption per person increased by 15% worldwide, 25% in developing countries, and more than 36% in China.but also for potted plants and cut flowers. , this thermal expansion is calculated to have the largest current influence on average sea level changes.