This is not autumn in Austin, but a particularly severe area of drought mortality.
Heat Extremes and the Future
This years’ heat extremes have been caused by:
- Climate change of course, the effects of which are now in the nonlinearly increasing phase of climate change where we have significantly warmed above our old climate.
- Air pollution regs in China, India and shipping, that are decreasing global cooling sulfate emissions similarly to air pollution regs in the US and Europe in the 1970s. I have only seen quantification of shipping, at a mid-point of 0.16 C increased warming, up to about 0.32 C.
- The Tonga Eruption in January 2022 that injected so much seawater into the stratosphere that this eruption is warming, not cooling like usual with sulfates, has been quantified at about 0.1 C warming and lasting 5 to 10 years.
- El Nino’s warming has a lag where it doesn’t really kick in until the fall and winter .
- La Nina’s cooling – Because of the tail of La Nina and ample spring rains, this summer was supposed to be mild.
What this all means is that several factors have contributed to this year’s heat in addition to climate change. Over the next several years these factors increase, then the Tonga eruption warming begins to decrease and El Nino changes to something else. Warming from air pollution regulations that limit cooling sulfate emissions will only increase for the next decade. The total estimated masking of warming from cooling sulfates is about half of warming we have experienced to date.