Are We Really Living in a Period of Unusual Climate Change or is it Normal?
First, as background to understanding what is happening today, we have to appreciate that we are living in an extended Ice Age that started about 2,500,000 years ago. Since about 1,000,000 years ago, there has been an about 100,000 year cycle of about 90,000 years of a cold glacial climate and about 10,000 years of a warmer interglacial climate. At the present time, we are at about 10,500 years into such a warm climatic period in which life prospers, there is abundant food, and there are no mass migrations from higher latitudes towards the tropics with resultant conflicts. It is possible that, for about 9000 of those years, the climate on Earth was warmer than today. On average, we should be heading into another cold glacial period with its associated problems for humans who already overpopulate the Earth.
The question is: Is the climate change and sea level rise we are continually being warned about something new and unusual in its impact, and caused by humans, or is it part of a natural cycle that has gone on well before the Industrial Revolution and significant CO2 emissions from energy production? Let’s look at the evidence that we can glean from the past.
It appears that, in the present warm interglacial period, Earth was at its warmest about 6000 years ago. The aborigines were only able to migrate to Australia about 50,000 -40,000 years ago because we were in a cold glacial period when sea level was so low globally that the English Channel did not exist and England was joined to Europe. From about 12,000 to 6000 years ago, the sea level then rose by about 130 metres at an average rate of about 2 metres every 100 years: today we are concerned about predictions of 0.3 metres every hundred years. Since then, the average global temperature has fallen by about 2 degrees Celsius and sea level has fallen about 2 metres from its highest point. So, sea level changes are normal in an Ice Age and projected sea level changes, even if correct from notoriously inaccurate computer models, are less than in the past.
We also have to realise that as well as sea level rising and falling, the land is also rising and falling as ice sheets load the crust and ice melting lowers that extra weight. So, in some parts of the world such as Norway, Sweden and Finland, the land is rising, making sea level apparently lower whereas in other such as England and The Netherlands the land is sinking. Venice is sinking slowly because it was built on marshland near a large fault which is lowering the land. The Mediterranean region as a whole has seen major relative changes in sea level in historical times. Anthony and Cleopatra are reported to have arrived by royal barge at the seaside port of Ephesus in Turkey, a Roman town which is now many kilometres inland from the sea. We are always being told that populations living on island atolls will have to migrate if sea levels rise. They live on submerged volcanoes that are sinking due to geological reasons but luckily the coral atolls grow at a faster rate than sea level appears to rise, as Charles Darwin first predicted but has been ignored in recent times. So, islands like Vanuatu may actually grow during sea level rise provided that there is not excessive extraction of groundwater or mining of the coral for cement and roads.
We are also being told that we humans are causing temperature increases that are much greater than in the past. However, records from central England indicate that the average temperature rose 2.2 degrees Celsius from 1696 to 1732, a period of 36 years. The maximum in 1732 was only reached again in 1942 and there has only been a 0.7 degree Celsius rise in the last 100 years. Global temperatures do not seem to have increased for the past 18 years, although they may be recorded as higher than average if Australia is viewed in isolation and comparative measurements over 100 years can be believed. The 2014 expedition to the Antarctic to follow the route of Sir Douglas Mawson and show the ice was melting is a good lesson to us all. We all now know from TV coverage that their vessel was stuck in ice that Mawson had successfully navigated and that one of the vessels sent to rescue them also was stuck in the ice. Perhaps they hadn’t read the report that the lowest temperature ever recorded on Earth was minus 94.7 degrees Celsius in Antarctica in August 2010!
So, there has always been climate change, the climate has been warmer than present over much of the past 10,000 years, and sea level has been much lower and slightly higher over the same period. The concern about human-induced climate change is concealing what we should all be concerned about: an overpopulated Earth with a population out of equilibrium with Nature, overusing non-replaceable resources, polluting our environment with really harmful substances, not just CO2 which actually supports life, and causing extinctions of other species. We need to recognise these bigger problems and deal with them. If there really is global warming, or equally likely global cooling, in the near future with slow changes to temperature and sea level, our ingenious technology can deal with it. Our human energy should be spent on considering ways of slowing population growth to a sustainable level and preparing for natural catastrophic events which are far more threatening than those involving slow change.
Much of the data discussed here is presented in far more depth in Ian Plimer’s Heaven and Earth and Not For Greens and discussed by characters in The Digital Apocalypse, a novel by the author, all published by Connorcourt Publishing