Every time a north wind blows hot air over Adelaide, some Chicken Little cries “Global Warming”. And when an El Nino predictably causes a hot year like 1998 or 2015/16, some sensation-seeker croaks “hottest year eevah”.
They are watching weather ripples and waves and ignoring the underlying climate tide. Daily, monthly and yearly temperature records will always be equalled or broken by extreme weather – that is what weather does. But to see what the climate is doing we must look long-term.
There are many signs that Earth’s climate is gradually cooling. Snow is accumulating. In the Antarctic, Mawson’s Hut and the Colbeck Hut are being progressively buried in ice. In Greenland, “The Lost Squadron”, which was forced to land on the Greenland Ice sheet in 1942, was rediscovered 50 years later buried under 268 feet of ice. Many glaciers are just a few thousand years old.
We live in the Holocene warm interval within the Pleistocene Ice Age – a time of recurring cycles of ice separated by brief warm interludes. Earth’s climate is driven by solar system cycles, and climate changes appear first in the Northern Hemisphere which has more land in the sensitive sub-polar regions. The GRIP ice core from Greenland shows the long-term average temperature there peaked 7,000 years ago and has trended down for 3,000 years.
We will still have hot days and heat waves but the climate mid-summer has passed and the temperature tide is going out. Spreading alarm about short-term temperature fluctuations of a fraction of a degree is a distraction.
And promoting damaging energy policies designed to prevent warming just as the next climate winter approaches will be seen by future generations as bizarre.