We all have them, friends who believe the planet is on a CO2-fuelled collision course with a catastrophe that can only be averted by directing large sums to rent-seeking wind farmers and the like. If you know someone like that, here’s a simple, handy guide to the climate scam.
A school teacher I know tells his pupils that ‘Saying does not make it so’, that facts are the key to knowledge, not opinions. Nowhere is this truer today than in the so-called ‘climate debate’. Here, much fails the facts test. Topping the list are claims of unprecedented warming from increasing atmospheric carbon dioxide (CO2). Resultant droughts, rising sea levels, more frequent and severe storms and other catastrophes are assumed. A switch from CO2-producing fossil fuels to renewable energy, especially wind and solar, is deemed essential.
Similar dire climate predictions have been around since the late 1970s. And in all that time, none has come true. None at all. Undeterred, the climate soothsayers ignore their failures and carry on as if nothing had happened. The fact that good science should produce good predictions, and this is not happening, is also largely ignored. Instead, impending climate doom, and what must be done to avoid it, is orthodox thought in much of government, academia and environmental groups everywhere. This thinking is much at odds with key facts.
A most important fact is that Earth’s four and a half billion year history tells us we are now cooler than average, not warmer. Indeed, for 80% of that history Earth had no ice caps and dinosaurs lived near the South Pole for millions of years. There were ice ages, too, with thick ice down to the Canadian border and across northern Eurasia. Indeed, this was the norm for the last 800 000 years, with ice ages, separated by warmer interglacial periods, coming and going each 100 000 years or so.
We are in the Holocene inter-glacial period now. It officially began 11 700 years ago, but not in a clear-cut way. Gradual warming followed the ice age peak about 25,000 years ago until a cold spell 14,000 years ago chilled things down again and temperatures swung wildly by 5C or so until the current warmer times began about 12,000 years ago.
During the last ice age, sea levels were some 130 metres lower than today, thanks to water locked-up in ice caps. With warmer times, some ice melted and seas rose to near current levels in just a few thousand years. Today, they are rising by only 16cm or so per century; a tiny change compared with the rapid changes in the early Holocene days and some contrary claims today. The lower sea levels exposed our continental shelf, joined Australia to Tasmania and PNG and left the Great Barrier Reef (GBR) high and dry for tens of thousands of years. Then, as the ice melted, Tasmania and PNG became islands and the GBR re-generated some 8,000 years ago in its previous position.
Similar things happened throughout the world. Rising Holocene waters separated England from Europe, formed the Dardanelles and the Black Sea and remade the world map. Humans flourished in the warmer climate, with 60% of the Holocene averaging 2C higher than today. The hottest time was some 7 000 years ago, with other peaks at 4000, 2000 and 1000 years back. Although there were no thermometer readings in these times, reliable proxies are available using lake sediments, pollen fossils and such, and evidence of what crops grew where and tree-lines on hills and in marginal areas. Indeed, the old joke that the Roman Empire went only as far north as wine grapes would grow has some truth to it. In fact, they grew grapes and citrus in parts of England that until recently would not support either crop. The Chinese too grew crops along the Yellow River in those times that won’t grow there today. And, for history buffs, Hadrian’s route across the Alps could not be used today as it is permanently closed with ice and snow.
Thus, we know that Holocene temperatures were often warmer than now and varied constantly – and wild temperature swings occurred just prior to the Holocene period. When we take this longer view, the recent temperature increase of about 0.8C since 1880 falls well within the limits of previous natural change, and is neither unprecedented nor dangerous.
