Global Warming Commenced many years ago


Many people have difficulty grasping the idea of a gradual warming across the planet. They also continue to confuse weather and climate as most of our weather still falls within the extremes of hot and cold. But gradually the earth’s climate is warming around the globe as the illustration of the normal curve above depicts.

You still get cold weather, but mostly it is warmer, and with much more extreme weather events that are on the hot side rather than the cold. The new curve – the shaded red area – is flatter than the curve of last century. This means less moderate or normal weather and far more extreme weather. This extreme weather is overwhelmingly on the hot side which includes heatwaves and the fact that generally speaking, at least 6 new heat records are set for every cold one. This information is not new and was clearly predicted by CSIRO climate scientists in the late 1980s.

The weather in Gippsland is becoming milder although we still get occasional cold snaps and light frosts. Because we are becoming used to the milder weather we tend to notice the colder snaps more and can be deceived. But personal accounts or anecdotes of cold spells do not translate into climate. For climate is the aggregate of weather across large areas of earth over a considerable period of time. It may come as a shock to many of us that not only has the climate of the earth been gradually warming over our own lifetimes, it has also been warming over our parents, grandparents and great grandparent’s as well.

Studies using data from coral, tree rings, cave decorations and ice cores have indicated that parts of the earth started to warm in the 1830s. This was, more or less, just 50 years after the start of the industrial revolution in England when mining and manufacturing began consuming large amounts of coal and spewing carbon dioxide into the atmosphere. Amazingly this was just a few years after French mathematician Joseph Fourier postulated the presence of the greenhouse effect, thirty years before Tyndall discovered that carbon dioxide and methane were the main greenhouse gases and nearly 70 years before Svante Arrhenius made his first calculations about increasing greenhouse gases and a warming earth.

With hindsight, and much scientific endeavour, this is exactly what the laws of physics, as founded by Fourier et al predicted – that after a given certain, but unknown, time lag (of about 50 years?) the warming of the earth would commence.