This series is adapted from his latest book, 'Hot Talk, Cold Science - Global Warming's Unfinished Debate,' published this month by the Independent Institute, Oakland, California. Despite forecasts of floods, droughts, and rising sea levels, the climate record actually gives little guidance. In truth, climate is forever changing, and in many cases for reasons we do not yet understand.
Volcanic eruptions occur frequently and can have significant effects on climate over the short term.
On a longer tirne scale, the Earth has experienced some 17 Ices Ages in the last 2 mlllion years. Since about 1880, we've had 'global' thermometer records, though large portions of the southern Hemisphere and the oceans have not been regularly monitored. Also, studies have shown that urban growth around these ground-based temperature stations has created a false increasing temperature trend. It has only been since 1979, using weather satellites, that scientists have been able to record truly global temperature readings from the lower atmosphere. According to these satellite data, global temperatures over the last two decades have been heading slightly downward.