Air-Hockey-Tables-7.jpg' alt='Harvard Air Hockey Table Manual' title='Harvard Air Hockey Table Manual' />Global Warming Just Facts Instruments located on satellites can measure certain properties of oxygen that vary with temperature. Data from these instruments is used to calculate the average temperatures of different layers of the Earths 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. Kash Rangan is the Malcolm P. McNair Professor of Marketing at the Harvard Business School. Formerly the chairman of the Marketing Department 19982002, he is now. Edit Tell us where you are located and we can tell you whats available. F 0. 3. 3C between the 1. For reference, a temperature analysis of a borehole drilled on a glacier in Greenland found that the location was about 2. F 1. 2C colder during the last ice age than it is now. 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. A 2. 01. 1 paper in the International Journal of Remote Sensing estimates that the accuracy of satellite derived temperatures for the lower troposphere is approaching 0. F 0. 0. 3C per decade, or 0. F 0. 1C over 3. According to temperature measurements taken near the Earths surface that are correlated and adjusted by NASAs Goddard Institute for Space Studies, the Earths average temperature warmed by 1. F 0. 8C between the 1. According to temperature measurements taken near the Earths surface that are correlated and adjusted by the Climatic Research Unit of the University of East Anglia in the U. K., the Earths average temperature warmed by 1. F 0. 8C between the 1. Sources of uncertainty in surface temperature data involve very incomplete temperature records in the earlier years,5. A 2. 00. 6 paper in the Journal of Geophysical Research that calculates uncertainties in surface temperature data states that a. Oceans constitute about 7. Earths surface. 7. Changes in air temperature over the worlds oceans are typically based on measurements of water temperature at depths varying from less than 3 feet to more than 4. This data is combined with changes in air temperature over land areas to produce global averages. A 2. 00. 1 paper in Geophysical Research Letters contrasted water and air temperature changes in the tropical Pacific Ocean using three sources of measurements. One of these was a series of buoys, each containing thermometers located ten feet above the water and at one foot below the water. The study found that water temperatures increased on average by 0. F 0. 1. 3C per decade between 1. F 0. 0. 1 to 0. 0. C per decade during the same period. A 2. 01. 1 paper in the Journal of Geophysical Research examined the locations of 1,0. Adrenaline Junkies And Template Zombies Free Pdf. United States. The paper found that 9. F 1C or more. 7. For example, some stations are located over asphalt making them hotter at certain times, and others are located in partial shade making them cooler at certain times. By comparing data from poorly positioned stations with other stations that are properly positioned, the study determined that the temperature irregularities in the poorly positioned stations cancel one another so that their average temperature trends are statistically indistinguishable from the properly positioned stations. As of July 2. 01. From 1. 97. 92. 01. F 0. 0. 7C. The largest gap between any of the datasets in any year was 0. F 0. 2. 1C, and the smallest gap was 0FC 8. 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 1. United Nations and World Meteorological Organization. It is the leading international body for the assessment of climate change,and its work serves as the key basis for climate policy decisions made by governments throughout the world. The IPCC states. To determine whether 2. The first IPCC report 1. It shows a Medieval warm period that was warmer than the present era and a Little Ice Age that was cooler. The report states that. Little Ice Age rather than a direct result of human activities. So it is important to recognize that natural variations of climate are appreciable and will modulate any future changes induced by man. The second IPCC report 1. Earths Northern Hemisphere from 1. The third IPCC report 2. Little Ice Age and Medieval Warm Period appear to have limited utility in describing global mean temperature changes in past centuries. The report contains the following graph of average temperature changes in Earths Northern Hemisphere, showing higher temperatures at present than at any time in the past 1,0. This graph is called the hockey stick graph because the curve looks like a hockey stick laid on its side click on the footnote for a graphic illustration. The red part of the curve represents modern instrument measured surface temperatures, the blue represents proxy data, the black line is a smoothed average of the proxy data, and the gray represents the margin of error with 9. The IPCCs hockey stick graph was adapted from a 1. Geophysical Research Letters authored by climatologist Michael Mann and others. This paper was based upon a 1. Nature. 9. 59. 6 Multiple versions of this graph appear in different sections of the IPCC report, including the Scientific section,9. Synthesis,9. 8 and twice in the Summary for Policymakers. This graph has been the subject of disputes in scientific journals,1. Freedom of Information Act lawsuit. Just Facts presently does not have the resources to conclusively assess all the competing claims on this issue, but the facts we have verified are as follows. The visual accord between the red instrument measured surface temperatures and the blue proxy derived temperatures is the result of statistical operations, not concurring data. The authors used a statistical operation to generate the graph that does not yield a simple average of the proxy data but emphasizes any data with a hockey stick shape, placing up to 3. When this statistical operation is not used, the hockey stick shape does not appear in the statistical measure that shows the closest fit to the data. The shape appears in measures that show subordinate trends in the data. The gray areas representing the margin of error fail to account for model uncertainty. The fourth IPCC report 2. Northern Hemisphere over the past 1,3. This graph, which is called a spaghetti graph, is constructed with data from 1. Click here for facts about the IPCCs practice of splicing proxy studies with instrument measured surface temperatures. The fifth IPCC report 2. This report contains the following spaghetti graphs of proxy studies spliced with instrument measured surface temperatures the black lines 1. The following are sources of uncertainty in proxy derived temperatures. Very few proxy series are truly independent There is a degree of common input to virtually every one, because there are still only a small number of long, well dated, high resolution proxy records. A 2. 01. 1 paper in the Annals of Applied Statistics found that the most comprehensive publicly available database of proxies do not predict temperature significantly better than random series generated independently of temperature. The raw data are generally subjected to some form of statistical manipulation, through which only part of the original climate information can be retrieved typically less than 5. Most proxies respond to seasonally specific temperatures, not to average annual temperatures.