Political Scenarios for Climate Disaster

There is no realistic scenario for addressing climate change that does not involve a comprehensive reorganization of human societies in the reasonably near term. Yet we emphasize reorganization, not collapse or apocalypse. As a species, humanity will almost certainly survive the coming centuries. But who will survive, and how they will live, is genuinely uncertain. The distribution of the burdens of substantial adaptation—which is now inevitable, whatever the extent of future carbon mitigation—and the political-economic means by which distribution is implemented: these are urgent issues facing us all.
— Read on www.dissentmagazine.org/article/political-scenarios-for-climate-disaster

Heatwaves: Changes in frequency and intensity

I’ve found myself thinking a lot about this paper by Herold et al. over the past few days. It describes the far-reaching implications of climate change for health and agriculture across different regions within Australia.

In particular I keep thinking about the implications of these two graphs:

The first graph shows heatwave frequency and the second one shows heatwave amplitude for different Australian cities for the recent past (blue), near-future (green) and far-future (red). Bottom and top of boxes indicate the 25th and 75th percentiles.

NB: For those not familiar with it, heatwave amplitude is a way of measuring and modelling the hottest day of the hottest heatwave within a year. This is different from the other common way of measuring heatwave intensity– magnitude–that looks at the average temperature across all heatwave days within a year. °C2 is a heatwave unit of measurement and isn’t the same thing as degrees Celsius.

There are many impacts and consequences associated with this model, but the frequency and scale of near- and far-future heatwaves alone should terrify us.

Source: Herold, N., M. Ekström, J. Kala, J. Goldie, and J. P. Evans. 2018. “Australian Climate Extremes in the 21st Century According to a Regional Climate Model Ensemble: Implications for Health and Agriculture.” Weather and Climate Extremes 20:54–68.

Australian climate extremes in the 21st century according to a regional climate model ensemble: Implications for health and agriculture

Estimated increases in daily excess mortality due to daytime temperatures above 30 °C are highest for Sydney and Brisbane under a far future climate (76.8 and 32.5 more deaths, respectively). For Sydney this is largely a result of the population’s sensitivity to high temperatures, whereas for Brisbane it is largely due to the increase in the number of hot days.

Source: Australian climate extremes in the 21st century according to a regional climate model ensemble: Implications for health and agriculture – ScienceDirect