And every one that heareth these sayings of mine, and doeth them not, shall be likened unto a foolish man, which built his house upon the sand:
When it comes to projections of global climate change, garbage-in, garbage-out (GIGO). The foundation of science is sound observation, good data.
From the Executive Summary, emphasis added:
“Global warming is one of the most serious issues of our times. Some experts claim the rise in temperature during the past century was “unprecedented” and proof that immediate action to reduce human greenhouse gas emissions must begin. Other experts say the warming was very modest and the case for action has yet to be made.
The reliability of data used to document temperature trends is of great importance in this debate. We can’t know for sure if global warming is a problem if we can’t trust the data.
… Until now, no one had ever conducted a comprehensive review of the quality of the measurement environment of those stations.
… In fact, we found that 89 percent of the stations – nearly 9 of every 10 – fail to meet the National Weather Service’s own siting requirements that stations must be 30 meters (about 100 feet) or more away from an artificial heating or radiating/reflecting heat source.
In other words, 9 of every 10 stations are likely reporting higher or rising temperatures because they are badly sited.
It gets worse. We observed that changes in the technology of temperature stations over time also has caused them to report a false warming trend. We found major gaps in the data record that were filled in with data from nearby sites, a practice that propagates and compounds errors. We found that adjustments to the data by both NOAA and another government agency, NASA, cause recent temperatures to look even higher.
The conclusion is inescapable: The U.S. temperature record is unreliable.
The errors in the record exceed by a wide margin the purported rise in temperature of 0.7º C (about 1.2º F) during the twentieth century. Consequently, this record should not be cited as evidence of any trend in temperature that may have occurred across the U.S. during the past century. Since the U.S. record is thought to be “the best in the world,” it follows that the global database is likely similarly compromised and unreliable. …