Remarkable new scientific evidence has been published that suggests abrupt rises in temperature have been a feature of global climate change going back to the iceless Jurassic period over 150 million years ago. These warming events, in which the temperature rose many degrees centigrade within decades or less, were thought to be a feature of the last ice age up to 100,000 years ago and confined to Greenland and the North Atlantic. This dramatic new evidence suggests they were a feature across the globe going back millions of years.
The findings will give fresh insight into the highly politicised debate around climate science and Net Zero. It is constantly argued that the recent small rise in global temperature, which started over 200 years ago, is unprecedented, and is caused by humans burning fossil fuel. Far from being unprecedented, it seems similar changes in temperature over comparable, and often shorter, time periods were ubiquitous across paleoclimatic history stretching back to the Jurassic era.
A group of French scientists led by Slah Boulila from the Sorbonne carried out extensive research into what are known as Dansgaard-Oeschger (DO) events. These events, named after two paleoclimatologists, track 1,500 year temperature cycles when large rises suddenly occurred followed by a reversion to ice age conditions. The scientists noted warming up to 15°C within a few decades, “pointing to abrupt and severe changes in Earth’s past climate”. Scientists and green activists seeking to downplay the significance of large changes in the paleoclimatic record have suggested that oscillations of northern hemisphere ice sheets and surrounding waters played a part.
But the French scientists now say that paleoclimatic studies have shown that the 1,500-year climate cycle is no longer restricted to the North Atlantic Ocean of the last glacial period. “The 1,500-year cycle is documented in both hemispheres, in other oceans and in continents, such as in lake and river deposits, in pollen fossils, in stalagmite proxy records, and in loess-paleosol deposits,” they add. In conclusion, the scientists note that the analysed paleoclimate records of the late Jurassic “supports the global nature of DO-like event, and in particular that their potential primary cause is independent of ice sheet dynamics”.
Of course, the inconvenient fact that the planet has seen countless significant temperature rises in the past is not unknown. Back in 1999, before global climate hysteria got into its full stride, geographer Mark Maslin from Imperial College co-wrote a paper on “sudden climate transitions” in which he stated: “All the evidence indicates that most long-term climate change occurs in sudden jumps rather than incremental change.” He went on to add that some, and possibly most, large climate changes involving movements of several degrees occurred at most on a timescale of a few centuries, sometimes decades, “and perhaps even a few years”.
These days Maslin is Professor of Earth Systems Science at the politically-named UCL Anthropocene, and tweeting that “Earth is already becoming unliveable”. A frequent guest on BBC programmes, Maslin has explained that the Anthropocene began with European colonisation and mass slavery. The origins of racism and climate emergency “share common causes”. Climate change politics helps build “a new political (and socio economic) system”. In 2018, he was one of a number of eco-activists who signed a letter to the Guardian saying they would no longer “lend their credibility” by debating climate change scepticism.
It would seem that the record of large – often startlingly large – rises in past temperature needs to be downplayed if the command-and-control Net Zero project is to be promoted. Removing fossil fuel from modern lifestyles within less than 30 years demands enormous economic and societal sacrifices, particularly from poorer members of society and across the developing world. It can only be done if enough people and populations believe there is an existential threat to the planet from recent warming and model-projected future warming.
Meanwhile, science continues to produce evidence of major temperature changes in the past. Two recent studies suggesting much higher temperatures are noted by the No Tricks Zone climate science site. A new study is said to have shown that it was warm enough 8,000 to 5,000 years ago for the plant Ceratopteris to have grown at 40°N in northern China. These days, the plant’s limit is 34°N, suggesting that winter temperatures in the past needed to be 7.7°C higher than today. Another warmth threshold species study argues that the Arctic Svalbard needed to have been 6°C warmer than today during the early Holocene. This is because 9,000 years ago, molluscs survived 1,000km north of where they are currently found.
Further details on the work undertaken by the Boulila team, including its scientific methodology, can be accessed here. More details about the two papers can be found on the No Tricks Zone. And further reporting on past global temperature changes by the Daily Sceptic can be found here.
Chris Morrison is the Daily Sceptic’s Environment Editor.