We are not on the brink of apocalypse. The world has continued to warm, due to accumulating carbon dioxide emissions. Of course, catastrophists are still with us, and surely always will be, but research has not supported the claims that humanity faces an existential threat. Most significantly, the most extreme climate scenarios that have dominated climate science and policy are not plausible. As a consequence, estimates of 2100 warming under “current policies” have declined from ~4°C to ~2.5°C. No one need take that from me, take it from the IPCC and UN FCCC.
Most types of extreme weather have not become worse. Floods, drought (hydrological and meteorological), tropical cyclones, and tornadoes have not had detectible changes according to the IPCC’s Sixth Assessment Report. Some signals have emerged — heat waves have become more frequent and heavy precipitation has increased in some regions. However, the fire and brimstone of AIT remains far from reality.
Those are just two of several points Roger Pielke makes in examining how Al Gore’s thesis in An Inconvenient Truth and the famous speech (a.k.a. sermon) he gave at the American Association for the Advancement of Science’s annual meeting have not held up in the 20 years hence.
Pielke explains that he, Pielke, misunderstood the problem with what Al Gore was doing and how he was doing it. Having thought of it as a science-understanding problem, he missed that it was actually akin to a religious movement of a apocalypticism. Thus, the reason Pielke calls it a revival sermon.
Continuing with another from Pielke, he appeared on The Human Progress Podcast this past week. Here are a few of snippets from the transcript:
Marian Tupy: Very good. So in this podcast, I want to spend most of our time talking about climate change and global warming and where we are. But I think probably the best thing to do is to start with the two extremes in the climate change debate. I don’t like to use the word denialist, but let’s look at that side first. So people who are critical of the dominant view that climate change is a crisis or even a problem will say things like CO2 concentrations in the atmosphere are much lower than what they were in the distant past of the planet. CO2 is vital for life, it is plant food, and it has led to global greening, which is a good thing. So nothing to worry about. What is wrong with that point of view?
Roger Pielke Jr.: Yeah, I mean, there’s a lot of what you say the science supports global greening and the fact that CO2 levels were higher in the past but where that goes away from scientific understanding is the “nothing to worry about” part. Anyone who claims to have certainty about the future, either we’re headed for the apocalypse or “don’t worry, be happy,” that’s not consistent with understandings of how humans are affecting the climate system. It always was and always will be a risk management problem. The late Steve Schneider, who was a famous climate scientist and climate activist I have this in my book he said at one time, the fundamental challenge of climate change is that outcomes could be very benign or they could be very serious and consequential, and we won’t know the difference during the time that we need to prepare. So both sides, I think, on both extremes the apocalyptics and the “don’t worry, be happy” folks are guilty of selectively interpreting evidence in a way that they think is favorable to whatever cause they want to advance. And the reality is that they’re both in that spectrum of possibilities, but smart decision-making has to consider that entire spectrum, not just one tail of the distribution on either end.
And then later:
Marian Tupy: We’ll get to the other side very soon. But the trade-off would be something like this. By emitting more CO2 into the atmosphere, we are making the world much richer so that even if we do have more CO2 in the atmosphere and it leads to some climatic problems down the line, the society is going to be so technologically advanced and so rich that we’ll be able to take care of it. Is there any evidence for that or is it mostly wishful thinking?
Roger Pielke Jr.: So humans are a fantastically inventive species. A lot of your work and a lot of the stuff I read that you put out emphasizes the progress that’s been made in making our material environments that much better off. And it’s absolutely true that fossil fuels, which have the side effect of emitting carbon dioxide, have been central to all of that progress. One data point, a trend that I think many people aren’t aware of, is that the carbon dioxide intensity of economic activity so technically it’s carbon dioxide per unit of GDP that has been steadily going down for as long as we have records, 60, 70 years. So as we’ve become wealthier, we’ve also become much less carbon intensive. And there are good reasons for that, and we could go into that, but it turns out that as a species we really like getting more output for less input, and that includes fuels. And we like cleaner burning fuels in terms of particulates in the atmosphere and other metrics. And so if that trend were to continue, then at some point we do go over the hump of increasing carbon dioxide emissions and it starts going down.
Roger Pielke Jr.: In fact, right now over the last decade, emissions have plateaued in the sense that there are small increases, but they’re within the margin of error measurement. And if you look to 20, 25 years ago, emissions were really going up fast, particularly due to coal consumption in China. So there is a background force that has nothing to do with climate policy that our economies have been decarbonizing. And so for those people on that side of the debate who really love CO2, we would have to intentionally take action to pump CO2 into the atmosphere because the long-term economic trends are in the other direction. I know it’s not as fast as some would like and it could be faster, but the decarbonization of the economy is just a fundamental reality of life on planet Earth.
And then later still:
Marian Tupy: Extreme weather events, especially hurricanes, cyclones, wildfires, and droughts.
Roger Pielke Jr.: Yeah, so I always say we gotta take these one by one. I’ve studied tropical cyclones for 30 years, which includes hurricanes, and the IPCC gets this one right also. There is not any convincing evidence that there’s more hurricanes, more intense hurricanes over the period of record. The IPCC is clear on that. The National Oceanic and Atmospheric Administration in the US, very clear on that. Hurricanes have become kind of a poster child. They’re very photogenic. Al Gore had one coming out of a smokestack in his famous movie. And hurricanes are probably one of the worst places to look for any signals of climate change. Simply, the numbers are small. There’s only 60 to 80 hurricanes on planet Earth in any given year. That’s a small number of events when you compare it to the millions and millions of temperature measurements we have everywhere every year. And the more measurements you have, the easier it is to detect small signals. Flooding, as I said, no detection or attribution. Drought, for most metrics of drought, again, no detection or attribution. The one distinction that the IPCC makes is soil moisture deficits, so think of dry land, which is associated with warming more than it is with precipitation. Winter storms, again, no detection or attribution there. What other events…?
The entire interview is definitely worth a listen. It is filled with his insightful (certainly not inciteful) perspective that brings careful balance and thoroughness to what is so often the fraught climate discussion. The message I always get from Pielke is: The climate is warming (and changing), humans are partially the cause, the implications are complicated and often misunderstood—the devil is in the details.