Australia is suffering from extreme fires and all good scientists are supposed to say, “Well, we can’t say these are the result of global warming.” And that is true to some extent. But these fires are demonstrating my greatest fear about global warming and it ain’t the average global temperature.
The science of global warming is more complex than most people realize. The most basic of theory shows, for example, that as radiative forcing increases, the poles warm the most and the equator the least. And the stratosphere cools while the troposphere warms. But mostly, the climate system is really complicated.
For example, there is much made of double-CO2 experiments. But they are not meant to be realistic. They are just a shorthand way to compare how different models respond to changes in radiative forcing. So the models run under current circumstances and double CO2 levels. The differences can be large. When I worked in the field, one model I used saw a 2C increase from double CO2 while another saw a 5C increase.
At the time, I figured the lower estimate was right. But since that time, it looks like the higher number is. The Earth’s climate is surprisingly sensitive to radiative forcing.
None of this matters, however. No one lives through climate; they live through weather. Think about it like a car traveling from San Francisco to Los Angeles at an average speed of 30 mph. That speed is meaningless if it runs you over. The only thing that matters is exactly what speed it was traveling when you were hit.
There clearly are problems with the temperature always being a few degrees warmer than usual. But the bigger problem is that having a higher baseline means more and harsher extreme events. Plants and animals have evolved to deal with temperature changes. But they aren’t evolved to deal with temperatures outside their normal range.
I realize most people — conservatives most of all — don’t think this matters to us because we can adapt. But we do sit at the top of the food chain. And while we air condition our way through a heatwave, not all the animals we depend upon can.
In addition to more extreme heat, we will also see more extreme drought. If anything, that’s even worse. And it combines synergistically with the heat.
All of this is to say that the Australian fires are the result of global warming. And this is how it will be.
I used to look forward to a time when even the global warming denialists would have to admit that they’d been wrong. But that won’t happen. For one thing, there are people who claim the Earth is flat. But more importantly, the worst effects of global warming will come in extreme events. And that means sudden mass extinctions. And sudden pain for us. Fun times!
But at least coal is cheap!
 These extreme events seem like they are coming on the order of once in the decade. But given the climate we had in 1850, these kinds of events would only occur every 10,000 years or more. I think we can thus use the shorthand that such events are due to global warming.