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Wednesday, March 6, 2024

Climate change is taking over the news - in case you hadn't noticed

I keep reading psychologists warning that talking about how terrible climate change will be is counterproductive. Rather than causing the deniers to see the error of their ways, it just makes them close their minds to further argument.

So this column isn’t for them. Rather, it’s to speak to the rest of us – those who don’t try to tell the scientists they’ve got it all wrong – to review the latest evidence that climate change is already upon us (what sane person could not have realised it?) and getting worse as each year flashes by our eyes.

I fear for my five grandkids’ future (as I may have mentioned before) but, to tell the truth, I’m glad I’ll be dead and gone before it reaches its worst. What we must do, like all those who voted teal at the last election, is to press both major parties to speed up our efforts and make Australia a leader rather than a laggard in the global push to limit how bad it gets.

Professor Albert Van Dijk of the Australian National University, an expert on precipitation, is part of an international team of researchers who’ve issued a report, the Global Water Monitor, using data from thousands of ground stations and satellites to document the effect of last year’s record heat on the world’s water cycle.

“We found global warming is profoundly changing the water cycle,” he says. “As a result, we are seeing more rapid and severe droughts, as well as more severe storms and flood events.”

Van Dijk says the most obvious sign of the climate crisis is the unprecedented heatwaves that swept the globe in 2023. Some 77 countries experienced their highest average annual temperature in at least 45 years. This “gave us a glimpse of what a typical year with 1.5 degrees Celsius of warming may look like,” he says. Warming consistently more than 1.5 degrees above pre-industrial levels is expected to have extreme and irreversible impacts on the Earth’s system.

“The high temperatures were often accompanied by very low air humidity. The relative air humidity of the global land surface was the second-driest on record in 2023. Rapid drying of farms and forests caused crops to fail and forests to burn.

“Lack of rain and soaring temperatures intensified multi-year droughts in vulnerable regions such as South America, the Horn of Africa and the Mediterranean ... This continuing trend towards drier conditions is threatening agriculture, biodiversity and overall water security.”

Get this: “The world’s forests have been soaking up a lot of our fossil fuel emissions. That’s because plant photosynthesis absorbs carbon dioxide from the atmosphere. Large disturbances like fire and drought reduce or even reverse that function.”

Rising sea surface and air temperatures have been intensifying the strength and rainfall intensity of monsoons, cyclones and other storm systems, Van Dijk adds.

We saw this when Cyclone Jasper battered northern Queensland and severe storms formed in south-east Queensland, leaving a trail of destruction. The cyclone moved much slower than expected, causing torrential rains and widespread flooding.

Enough of that. Australia’s Climate Council, a community funded organisation created by former members of the Climate Commission after it was abolished by the Abbott government in 2013, has created a “heat map” using thousands of data points from the CSIRO and help from the Bureau of Meteorology.

If we assume, perhaps optimistically, that all countries meet their present UN commitments to reduce emissions, the heat map predicts that western Sydney will swelter through twice as many days above 35 degrees and three weeks above 35 degrees every summer.

Temperatures will be worsened by the “urban heat-island effect”, as materials such as asphalt and concrete amplify heat by as much as 10 degrees during extreme heat.

Melbourne, too, faces double the number of days above 35 degrees by 2050. Will it take that long for the Australian Open to be moved?

Which brings us to last month, when six transmission line towers in Victoria were destroyed by extreme wind gusts from thunderstorms, leading to about 500,000 people losing power. The intense winds knocked trees onto local power lines or toppled the poles. Some people went without electricity for more than a week.

A month earlier, severe thunderstorms and wind took out five transmission towers in Western Australia and caused widespread outages. In January 2020, storms caused the collapse of six transmission towers in Victoria.

And, of course, in 2016 all of South Australia lost power for several hours after extreme winds damaged many transmission towers.

Recent research by Dr Andrew Dowdy and Andrew Brown, of the University of Melbourne, suggests that climate change is likely to cause more favourable conditions for thunderstorms with damaging winds, particularly in inland regions. But more research is needed to confirm this.

Van Dijk gets the last word: “Overall, 2023 provided a stark reminder of the consequences of our continued reliance on fossil fuels and the urgent need but apparent inability of humanity to act decisively to cut greenhouse gas emissions.”