We are bombarded with claims that some month or year (e.g., 2016) is the “warmest ever.” But what does that mean? We are living in a relatively cool era. Temperatures today are lower than they have been something like 90% of the time since the last Ice Age ended 12,000 or so years ago. In fact, “ever” means since approximately the 1880s, when thermometer records became widespread. As it happens, that was also around the time when the Little Ice Age ended, so‚Äìhappily!‚Äìthe Earth is a bit warmer now than it was then.
One of the many problems with global warming hysteria is that it is based on the surface temperature record since the 1880s, which is deeply flawed when it is not outright falsified by alarmists who control the historical records. This happens often, as we and others have documented. This week’s The Week That Was from the Science and Environmental Policy Project explains some (but by no means all) additional problems with the surface temperature record:
Unfortunately, the IPCC, and others, use surface temperatures to evaluate the global climate models. The failure of the models to track the surface temperatures is not surprising. Historic data is very sparse, largely from western Europe and the US. The data is contaminated by significant changes in land use, particularly urbanization. And, as shown in the 2008 NIPCC report, since about 1970, there has been a marked decline in the stations used to establish surface temperatures, and dramatic decline in the number of 5 degree by 5 degree grid boxes covered. Around the year 2000 about 100 of the total of 2,592 possible grid boxes ([180/5] x [360/5]) were covered ‚Äì 4%. Complicating matters has been the trend, at least in the US, of using stations at airports. Both pavement and flying frequency create measurement problems.
When the Charney report was produced in 1979, there were no comprehensive, global temperature data. But starting in 1989, going back to December 1978, we have had comprehensive global satellite data of the atmosphere. As shown in the report by John Christy, the comprehensive satellite data show that, generally, the global climate models greatly overestimate warming of the atmosphere, where the greenhouse effect occurs. Both satellite and surface data are influenced by weather events such as the El Ni√±o Southern Oscillation (ENSO). But, since the satellite data is “cleaner” it should be easier to separate natural and other human effects from CO2 caused warming.
If the purpose of the models is to estimate the effect of CO2, then surface data are poor proxy data at best. Atmospheric data is far superior. The kindest possible justification for the IPCC, and others, not to use satellite data is mental inertia.
Actually, the explanation is political. The IPCC was explicitly established by the U.N. for one purpose only, to “study” the impact of human-emitted CO2 on global temperatures. This was for the purpose of justifying government control over industry worldwide. Anyone who is interested in science rather than left-wing politics relies on the satellite data, which are transparent and have not been “adjusted” by political activists.