The return of the summer wildfires in California reminds us that the climate crisis has not gone away just because there is a pandemic. The USA has recently recorded the hottest ever measured temperature of 54.1 C (130 F) in Death Valley and 2020 is on track to be the hottest year on record for global average temperatures. A recent paper (Slater et al 2020) estimated total ice loss over the last 25 years at 28 trillion tonnes, which matches the worst-case-scenario predictions of the Intergovernmental Panel on Climate Change (IPCC).

And yet a substantial proportion of people in many countries deny the science, not only for human-caused global warming, but for coronavirus and vaccines. A recently published reconstruction of the earth’s global climate over the last 12,000 years illustrates starkly how different the rising global temperatures of the last decades have been from natural cycles. The figure below was prepared by Alexander Radtke (@alxrdk) with captions added by https://thelogicofscience.com/ using temperature data for the 12k->2k years ago from https://nature.com/articles/s41597-020-0530-7, for the 2k->170 years ago data: https://nature.com/articles/s41561-019-0400-0 and for 1850-2020 it is an equal blend of HadCRUT 4, GISTEMP, Berkeley Earth, Cowtan and Way and NOAA datasets.

Climate change denialists like to argue that climate changes naturally. It does, but the graph makes clear how different the rate of change has been since the mid-20^th century, and by hom much it exceeds the limits of natural climate change. The climate fluctuates naturally in a roughly 10,000 year cycle and its clear from the graph that we should still be in a cold period, not the warmest by far in the last 12,000 years.