Measurements are inaccurate

• Temperature readings from reporting stations outside the U.S. are poorly maintained and staffed and probably inaccurate; those in the U.S., which are probably more accurate, show little or no warming trend (See http://wattsupwiththat.wordpress.com/ for more information)

• Temperature readings taken by terrestrial reporting stations are rising because they are increasingly surrounded by roads and buildings which hold heat, the “urban heat island” effect; methods used to control for this effect fail to reduce temperatures enough to offset it; See Anthony Watt’s “How not to measure temperature series” at http://wattsupwiththat.wordpress.com/2008/07/07/how-not-to-measure-temperature-part-66/

•Sufficient data exist to measure changes in mass for only 79 of the 160,000 glaciers in the world

• Computer simulations are not real-world data and cannot be relied on to produce reliable forecasts. Data is usually inputted by persons looking for specific outcomes. See http://www.landshape.org/enm/ for more information.

 
•Surface • Surface monitoring stations are not the only evidence that the planet is warming. satellite data, radiosondes, borehole analysis, glacial melt observations, sea ice melt, sea level rise, proxy reconstructions, and permafrost melt all conclusively show that the planet has undergone a pronounced and rapid warming over the past century and a half. So even if the entire surface temperature record were contaminated beyond use, there would still be no doubt whatsoever that the planet is warming.

•Aside • Aside from this, it has been demonstrated in several independent studies (Peterson, 2003) that the urban heat island effect does not significantly affect the surface temperature record. That is, the 20th century warming trend is not simply an artefact of urban development.


•It is • It also important to note that the warming trend is not an output of a computer model, but a conclusion based upon observing real-world evidence such as that listed above.