Past temperatures
From ClimateSkeptics
Contents |
US Surface station accuracy
Surfacestations.org is an all volunteer effort run by veteran meteorologist Anthony Watts to document the quality of weather stations. The website contains all of the instructions one would need to gather enough information to determine if a weather station meets the requirements of NOAA. The data is collected and displayed on the website for others to study. According to the participation rules, weather station maintainers are given the opportunity to correct any errors in survey forms, diagrams, or photos in a form of independent review.
34.5% of the USHCN surface stations have been surveyed so far. Using a scale from 1 to 5, by which stations that are properly maintained receive a rating of 1 and stations that are severely compromised by artificial temperature signatures (being located adjacent to an artificial heating source, such as a building, rooftop, parking lot, or concrete surface, for example) receive a 5, the effort so far reports 70% of official temperature stations receive a 4 or 5 rating, and only 4 percent receive a 1.
NASA GISS Error
Steve McIntyre of ClimateAudit discovered a bug in the Goddard Institute for Space Studies (GISS) data of temperatures of US weather stations had a bug in their data sets due to an error while combining data from different data sets. It was previously thought that 1998 was the warmest year or record. After correcting for this bug 1934 turned out to be the warmest year.
Telegraph article on discovery
Steve McIntyre's post on this on ClimateAudit
The Northern Hemisphere Hockey Stick Graph
A graph showing reconstructed estimates of temperatures for the northern hemisphere by Mann, Bradley and Hughes which appeared in the IPCC report is the source of great controversy.
There are arguments over the statistical methods and the measurements used, though it is important to note that this graph only covers the Northern hemisphere. The well known Medieval Warm Period and Little Ice Age appears to be almost insignificant on this graph while historical and archaeological records indicate that these periods were significant. Selected sources from the Southern Hemisphere, like Patagonia and Tasmania, were also included in versions of the graph, but mostly only covering historical periods which could aid in equalising past temperature values. The Northern Hemisphere is covered by almost 40% land, meaning it has a land surface area double of that to the Southern Hemisphere, and more affected by urban heat and deforestation effects.
Hockey stick controversy article on Wikipedia
National Center for Policy Analysis - Revising 1,000 Years of Climate History
The M&M Project: Replication Analysis of the Mann et al. Hockey Stick
Global Satellite Temperature Measurements for both Hemispheres
From NASA temperature measurements for global, Northern and Southern Hemisphere we can see that the Southern Hemisphere (SH) has been ignoring global over warming since measurements began almost 3 decades ago.
Temperature data from NASA satellites
The warming is not 'global', this is why we can only correctly refer to it as 'climate change', since the climate is never constant anyway.
