What about the role of carbon dioxide in climate? Al Gore did a great job to dramatize the recurring glacial cycles in his widely acclaimed work of science fiction. But he missed two inconvenient truths.
First, ice cores show that in the glacial spring-time the temperature rose before the CO2 levels rose. Therefore, the rising CO2 cannot be a cause of the warming – it is a result of CO2 being expelled from the warming oceans.
Second, at the top of every summertime in the glacial cycle, the high levels of CO2 in the atmosphere were unable to prevent the cooling into the next cycle of ice.
We are already in the autumn of the current glacial cycle, and nothing man can do will change that. Global temperatures today are lower than they were in Roman and medieval times. They will still fluctuate with the effects of daily, lunar, yearly, and sun-spot cycles, but the long-term trend of maximum and minimum temperatures will continue drifting downward. Once summer temperatures in places like Siberia are unable to melt last winter’s snow, the already growing glaciers will join to form ice sheets, and Earth will once again be gripped by another long Glacial Winter.
The transition from Greenhouse Earth to Icehouse Earth always occurs suddenly. Once our verdant greenhouse is gone, life of Earth will never be the same again.
The warm days, seasons, years, and epochs have never been a deadly threat to life on Earth. Frost, snow, hail, and ice are the killers. If our descendants do not have the energy, resources, and wisdom to keep their people warm and fed through the coming glacial epoch, humans may follow our Neanderthal cousins, who perished in the last glacial winter, just 20,000 years ago.
It is a wonder of the modern era that people who cannot accurately forecast next weekend’s weather claim they can regulate the temperature of the whole globe by bashing industry and taxing carbon.
There is no evidence in climate history that carbon dioxide has a detectable effect on global temperatures. However, if our continued use of cheap, reliable hydrocarbon energy does slightly delay the onset of the next glacial winter, we and all life on Earth should count ourselves extremely lucky.
Viv Forbes is a qualified geologist who has spent much of his life studying geological and climate history as written in the rocks. He has also spent several years in formal and private study of climatology and meteorology. He is the founder of the Carbon Sense Coalition and a non-executive director of a small Australian company developing a coking coal mine.