Accuracy range of carbon dating
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 0.23ºF (0.13ºC) per decade between 19, while air temperatures cooled by 0.02 to 0.09ºF (0.01 to 0.06ºC) per decade during the same period. examined the locations of 1,007 of the 1,221 monitoring stations used to determine average surface temperature changes across the continental United States.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.Climate models have to be tested to find out if they work.We can’t wait for 30 years to see if a model is any good or not; models are tested against the past, against what we know happened.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.
All models have limits - uncertainties - for they are modelling complex systems.Testing models against the existing instrumental record suggested CO2 must cause global warming, because the models could not simulate what had already happened the extra CO2 was added to the model.All other known forcings are adequate in explaining temperature variations prior to the rise in temperature over the last thirty years, while none of them are capable of explaining the rise in the past thirty years.However, all models improve over time, and with increasing sources of real-world information such as satellites, the output of climate models can be constantly refined to increase their power and usefulness.Climate models have already predicted many of the phenomena for which we now have empirical evidence.