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.
He informed the * In 2013, “Forecast the Facts”—a “grassroots human rights organization dedicated to ensuring that Americans hear the truth about climate change”—published the following graphic purporting to show a recent photo of the North Pole: * After publishing an article documenting the facts above, Just Facts contacted Forecast the Facts to offer an opportunity to respond. As of January 2016, Forecast the Facts has not replied or issued a correction.  * The natural variability of Earth’s climate is such that a glacier formerly existed on Hawaii, and glaciers once covered almost all of Canada, New England, and the northern central United States: * In addition to carbon dioxide emissions from the use of fossil fuels, other factors that have been implicated by scientists as primary causes of modern climate change include but are not limited to: * A central debate among scientists about man-made greenhouse gases involves how much natural processes reduce or amplify the effects of these gases.
Positive feedbacks amplify the effects, and negative feedbacks diminish them. * The climate models included in the 2007 IPCC report are programmed with positive feedbacks for water vapor that more than double the warming effect of CO2. This is based upon the fact that warmer air evaporates more water, thus creating more water vapor, which is a greenhouse gas.  states that the feedbacks used in climate models are based upon “methods that …
The following map shows these productivity changes, with green signifying higher vegetation productivity and red lower: Plants need water, light, warmth, nutrition and CO2 to grow.
By increasing the CO2 level in the greenhouse atmosphere (typical to 600 ppm instead of normal 400 ppm value), the growth for some plants can be stimulated in an important way, with often yield increases up to 20%, especially for tomato, cucumber, strawberry, etc.
The report states that: some of the global warming since 1850 could be a recovery from the Little Ice Age rather than a direct result of human activities.
The second largest influence is calculated to be the melting of glaciers and mountain icecaps. Per a 2010 paper in * Worldwide, sea level is not evenly distributed like it is in small bodies of water such as lakes.
For instance, the sea level in the Indian Ocean is about 330 feet below the worldwide average, while the sea level in Ireland is about 200 feet above average.
Such variations are caused by gravity, winds, and currents; and the practical effects of these phenomena are dynamic.
As of July 2015, no similar study has been conducted on a global basis. * From 1979–2014, the three temperate datasets posted above differed from one another by an annual average of 0.13ºF (0.07ºC).
The largest gap between any of the datasets in any year was 0.38ºF (0.21ºC), and the smallest gap was 0ºF/C: * To reconstruct global average temperatures in the era before instrumental measurements were made on a global scale, scientists use proxies that respond to changes in climate, such as the widths of tree rings and certain elements of the geological record, to estimate temperature variations in the past.  * The Intergovernmental Panel on Climate Change (IPCC) is a scientific body established in 1988 by the United Nations and World Meteorological Organization.