One of the main reasons for last year’s ‘spike’, which the media and government agencies have avoided mentioning, is the Hunga Tonga volcano eruption two years ago. Volcanoes usually cool the world because of the plume of ash and other particles they eject. However, Hunga Tonga started as an undersea eruption, so the amount of ash was relatively small. What it did send skyward was a massive plume of water vapour which reached the stratosphere, where it remains and will do so for several more years.

50 times more potent than CO2, water vapour is by far the most potent of greenhouse gases, and scientists believe that Hunga Tonga was responsible for a large chunk of last year’s warming. But claims that it was the hottest year for the last 100,000 years or so simply don’t stack up against the evidence.

For decades, proper climate scientists, such as H. H. Lamb, have known that the early to mid-Holocene was much warmer than now – this is the period from the end of the Ice Age up to about 3000 BC.

They even gave it a name – the Holocene Optimum – because the warmer climate was a boon for civilisation. They say the same about other warm periods since, such as Roman times and the Middle Ages.

The evidence for this is widespread, powerful, and undeniable. Above all it does not rely on dodgy computer models and unreliable proxies.

Ice cores, for instance, tell us a lot about past temperatures, and the ones in Greenland clearly show the Holocene Optimum, and also indicate that the Little Ice Age, which ended in the 19th century, was the coldest era since the Ice Age.

All sorts of other evidence from around the Arctic, such as glaciers and remains of forests where on frozen tundra that was previously covered with glaciers, support the evidence from ice cores. Elsewhere treeline studies from the Rockies, European Alps, Carpathians, Japan, New Guinea, Australia, New Zealand, East Africa, and the Andes show that trees used to grow at much higher altitudes than they do now – powerful evidence of a much warmer climate. And as glaciers from Alaska to Patagonia and the Alps to Iceland retreat, we are now finding remains of trees dating back to the Middle Ages and the Roman era.

Denmark’s leading glaciologist, Prof Jørgen Peder Steffensen summed it up best in this recent video:

The climate alarmists tell us that 2 degrees of warming will destroy all life on earth, but Dr. Steffensen just showed us that up to 4,000 years ago temperatures were…2 degrees warmer. This leaves the climate alarmists with a conundrum. Either they have to admit that 2 degrees of warming would actually be good for the planet, or they have to believe that all life on earth started about 4,000 years ago.

The Discovery of Global Warming February 2011
Hubert Horace Lamb (1913-1997) was one of the first meteorologists to point to changes of climate in human history. From records of European temperatures, especially a remarkably long series from central England, he deduced what he called a "Medieval Warm Period" and a "Little Ice Age." He was the founder and first Director (1971-1977) of the Climatic Research Unit at the University of East Anglia, a center for research on the evolution of the modern global climate. In his magisterial 1977 volume Climatic History and the Future, he renounced his earlier view that the world was bound to get cooler. Global warming due to humanity's emissions of carbon dioxide, he wrote, was likely to "gain the upper hand in the next century unless stronger controls are instituted than any that are believed to be contemplated..." (p. 677).