And Iffn They Did? Transcript

John Robson:

Close to the core of climate alarmism is the notion that the Earth is manifestly too hot already and overheating fast, primarily because of man-made CO2, plus other “greenhouse gasses”, which we must at the very least stop adding to the atmosphere and ideally get a good deal of it out. Some people favour “carbon capture and storage” just to stabilize current levels. But many others want to reduce those levels, and they warn us of disaster if they fail to do so.

But what if they succeed? For the Climate Discussion Nexus I’m John Robson, this is a “Crystal Ball” look at the alarmists’ dreamworld with dramatically reduced levels of atmospheric CO2. Which turns out to be a nightmare.

It is commonplace among people concerned about global warming that we must limit the temperature increase since around 1850 to 1.5 Celsius, or at worst 2 degrees Celsius. And many computer simulations say even if we did reach Net Zero by 2050, we humans will still already have released too much “carbon pollution”, pushing the planet into a runaway greenhouse effect where a series of tipping points triggers mass extinctions and other disasters.

So they’re seriously exploring projects from the quirky to the bizarre to draw down atmospheric CO2 and, they hope, cool the Earth to the ideal temperature. And these schemes probably won’t work. But what if they do, at least part way? As a viewer asked us “what happens with insufficient CO2?”

Here let us interject that the debate over climate change doesn’t consist of one group saying confidently that they know precisely what will happen if we add more CO2 to the atmosphere, or what will happen at any level of CO2, and that more CO2 means a warmer and more horrible world, while the other says yes, we know exactly what will happen but it will be harmless or beneficial. On the contrary, a crucial distinction between orthodox alarmists and most skeptics is that the latter are convinced that climate is very complicated, that it’s “non-linear” in a technical mathematical sense, so that we famously can’t predict the weather next month and we certainly can’t predict what it’s gonna be like in the next century.

The computer models and their creators feign that kind of capacity. But of course they can’t even predict the known past let alone the unknown future; none of their models can take conditions in 1812 and predict 1912, for instance. Or put in 49 BC and predict 490 AD. Or put in 50 million BC and predict 35 million BC, or today or anything else. And I wanna be clear about this: Here at CDN we don’t claim that we can do that stuff either. We don’t even know whether, if they did manage to reduce atmospheric CO2, the temperature would go down.

But within limits we don’t need clairvoyance here. We only need history. We just have to look back a few tens of thousands of years to see a colder world with dramatically less CO2 and judge what it’s like. In fact, we only have to look back a few decades or a couple of centuries to see a world with somewhat less CO2, and somewhat less warmth, and understand reasonably well what the consequences would probably be of getting back even to around, say, 280 parts per million of CO2 in the atmosphere, let alone 180.

Now again, when I say reasonably well let me insist that there’s still a lot of uncertainty here. And in fact that’s one of the reasons that I would argue that the famous “Precautionary principle” requires us to think hard about what would happen if a “successful” intervention in atmospheric CO2 took us back past 1850, or 1750, or 1650 to one of those famous “tipping points”, so that we went right past another “Little Ice Age” into a full-blown glaciation, as cooling oceans absorbed more and more CO2 and there was no way to slow down.

But one thing at a time. Even if all the alarmists manage to do was get us back to precisely where they wanted in terms of atmospheric CO2, that is the early 19^th century, in that case, crops would wither, people would go hungry and they’d become vulnerable to disease, civilizations might well crumble. And that’s just CO2. If they also get their wish that by reducing CO2 they reduce temperature, these effects will get stronger and, paradoxically, the weather that they were trying to make better would get worse.

And the fact that cold is actually bad for crops, as are lower levels of CO2, raises a vital preliminary question again. That of uncertainty.

All proposals for carbon sequestration, for reducing atmospheric CO2 and so forth, assume that we know how warm or cold it “should” be, as well as how to make it that warm or cold. But, therefore, alarmists should be asked far more often and persistently than they are: “How do you know what the ideal temperature is?”

And here casual talk of 1850 as “pre-industrial times” actually makes things worse rather than better, partly because 1850’s actually well after the industrial revolution, which you’d think they’d know, especially since some of them are now claiming to find clear signs of human-induced warming by 1885. But mostly it’s a problem because the entire history of the Earth before 1776 was “preindustrial” and most of it was far warmer than in 1850. So, what was wrong with it being warmer then, what’s wrong with it being warmer now, and how do they know?

What makes the mid-19^th century the ideal, typical or “natural” temperature? And what evidence do they have that the weather was exceptionally good in 1850 or 1750 compared either with 2025 or 1225? Is there any real evidence that it was milder, or more stable, with fewer storms? Or do what records we do possess suggest that it was actually worse?

We’re all for nostalgia. We miss Queen Victoria. But if you’re going to be strident about getting back to 1850, in any way from clothing styles, manners, and social roles to the Pax Britannia and the weather, you should be able to explain why.

In looking at that scenario, we are gonna to set aside certain questions for the time being including whether CO2 really is the “control knob on the global thermostat” and why, if current temperatures threaten runaway warming, we didn’t get that kind of runaway warming over the thousands, millions and even billions of years in the past when the planet was a lot hotter. We’re just gonna focus on the question: Suppose that they do manage to lower atmospheric CO2, what happens? What happens if it doesn’t then reduce temperature? What happens if it does?

And here we do, despite all the uncertainties, know something for sure. A world with less atmospheric CO2, even if it doesn’t get cooler, becomes less fertile. Whatever anyone’s doubts about a linear relationship between atmospheric CO2 and temperature, there’s one linear causal relationship that nobody in their right mind doubts, and it’s between atmospheric CO2 and plant growth.

Climate alarmists talk so relentlessly about “carbon pollution” that it’s easy to get the impression of trees belching fumes. And as a matter of fact, in the early 1980s U.S. president Ronald Reagan was widely and effectively ridiculed for claiming that trees produce more pollution than cars.

It actually turned out that decaying organic matter does give off a variety of gasses, and some of them are obnoxious. But the notion that carbon dioxide might be among the problematic ones wasn’t on the horizon then. Nobody was worrying about that. Since then, they’ve become so overheated on the subject that it’s easy for the unwary to assume that a bit more CO2 will actually choke plants.

In fact, the reverse is true and we know it. It’s not just biology lab theory or the fact that greenhouse owners pump CO2 in to a thousand parts per million or more. It’s that, as we’ve catalogued, the rise in atmospheric CO2 over the last half-century has been accompanied by a massive greening of the planet on which alarmists are surprisingly reticent.

So we do know that if the alarmists get their way and reduce atmospheric CO2 to well under 300 parts per million, and getting back even to the levels of 1970s, never mind the 1870s, and even if it doesn’t make the planet get colder, there will still be a major die-off of plants including food crops and, with them, a major die-off of people, overwhelmingly poor non-white ones. If it gets colder, the scenario is even worse.

So, it seems like rather an odd goal. And there’s more.

Because an important part of the alarmist argument is that the weather in the 19^th century was better than it is today, better in the sense that there were a lot fewer hurricanes, especially major ones, there were fewer droughts, there were fewer floods, there were fewer weather catastrophes of almost any sort. And of course, as always, the record is incomplete, and the further back you go in time the more incomplete it becomes, and the more you have to rely on “proxies”, including to estimate temperature as well as atmospheric CO2 and things like hurricanes.

The proxies aren’t just inherently imprecise. They become less and less exact and dependable the further back we go. So, trying to estimate how many wildfires there were in California in 1200 AD is not remotely like trying to calculate how many there were in 2020. And of course it’s essentially impossible to know what the weather was like in the Eemian interglacial, the one that preceded the Holocene and was warmer than today with lower atmospheric CO2, never mind what the weather was like in the Age of Dinosaurs.

That being said, our #LookItUp series has repeatedly reminded people that what solid data we do have on such phenomena, and in many cases it does stretch back at least into the tail-end of the Little Ice Age, says that the weather was worse in 1850 not better. And eye-witness accounts, tax and crop records and other things of that sort, support the notion that the weather was pretty nasty in the Little Ice Age, and probably somewhat better in the Medieval Warm Period.

Moreover there’s a famous table in the IPCC’s 6^th, and latest, “Assessment Report”, in Working Group 1: The Physical Science Basis, Chapter 12, Table 12 (12.12) (p. 1856) in case you wanna look. And on that table dark blue shows that they have high confidence that something has increased, light blue “medium confidence” (which is 50-50) and then dark orange is high confidence in a decrease and light orange is medium confidence in a decrease, again a coin toss. And the first column is “Already Emerged in Historical Period” and guess what? It’s mostly blank, including everything for “Wet and Dry” and “Wind” and “Coastal”.

So, the IPCC is not confident that the weather’s getting worse. They think heat and atmospheric CO2 have gone up, and the only other thing they’re even 50/50 on is “Ocean salinity”. And then they have columns two and three, which are speculation about 2050 and 2050-2100 based on extreme scenarios, but even they’re mostly blank or, in two cases, split between an increase and a decrease.

So, when it comes to weather, “the science” says that getting back to 1850 or a bit earlier isn’t better and might be worse since for other reasons, we think that the Little Ice Age was actually notorious for foul storms.

That means that if they succeed in reducing atmospheric CO2 back to 19th century levels, with or without a temperature change, it’s a bleak scenario. But it’s also the best-case, because one of the odd things about alarmists and their vision is that they see the climate as massively unstable but in one direction only. Minor warmings, though only from current levels or above, tend to trigger runaway processes, hit tipping points and kaboom. But they don’t seem to believe that there are any tipping points the other way, and it’s hard to understand why climate would be rock solid there and totally brittle here.

So what if they’re half right?  What if it’s true that climate is unstable in the face of minor perturbations? Again, as we have through the video, we’re urging humility in the face of the complexity of climate, and whatever’s going on in the long run and why it’s happening, and also on the limits of proxy data. But, what if there are tipping points that could lead to a runaway cooling? Because we do know two things with considerable certainty.

One of them is that the planet has been much warmer than today for most of its history, again without triggering a runaway warming. And second, that over the last 2.58 million years or so, it seems a succession of brief warmish periods, warmer than today though cold by normal planetary standards, that instead of spiraling upwards into Max Max territory, have consistently spiraled downward into long-lasting glaciations that as far as we can tell seem to be getting colder.

So, if there are cooling as well as warming tipping points, then a successful attempt to slide this thermostat down 1.5C or so to the supposedly ideal mid-19^th-century “pre-industrial” conditions might instead trigger runaway cooling past another Little Ice Age into another glaciation. Which would create a disaster even worse than the ones we have described above, essentially wiping out agriculture.

During the boringly named Last Glacial Maximum, which was the peak of the last glaciation a mere 20,000 years ago, right before the thaw that mercifully turned into the Holocene warming, the planet was about 6° Celsius colder than it is today—that’s 11 degrees Fahrenheit, and it was desperately dry, brown and infertile. Atmospheric CO2 dropped to around 180 parts per million, which is perilously close to the 150 ppm at which all C3 photosynthesis plants globally would have died, including all trees and most of the plants that we later domesticated into crops.

It’s even been suggested the last glaciation ended because plants died off on such a scale that the Earth became so dusty that its “albedo,” that’s its tendency to reflect sunlight back into space, plummeted because of all the dirt including on the ice, which enable it to absorb enough solar energy to thaw and pull it and us out of a death spiral.

That time anyway. Next time, who knows?

We really don’t know, as we don’t actually know how many “glaciations” the Pleistocene has seen or why. And we don’t know because again the proxies become less reliable and less informative going backward, including that short-term changes in particular tend to vanish. So we have no way of knowing whether the warming we’ve seen since 1850 is unusually rapid by prehistoric or even historic standards. Although we’re pretty sure that today’s changes are nothing to the abrupt plunge into the Younger Dryas nearly 13,000 years ago and back out just over 11,500 years ago.

We certainly don’t know enough to bet our future on such a risky piece of geoengineering, and everything that we do know hollers “Don’t!”

Because the bottom line on reducing atmospheric CO2 is that as with most hubristic projects, it probably wouldn’t manage to accomplish much of anything except wasting money. The planet, even its oceans, are too big and we humans are too puny. But if it does work, as with most hubristic projects, it will probably trigger a catastrophe. And one for which there’s no excuse because it’s implicit in their goals

We know from experience that a more carbon-hungry world, especially if it’s also colder, would see crops failing and the weather deteriorating even if we don’t hit a tipping point back into a devastating glaciation. Even if reducing CO2 doesn’t lower temperature, we’ll still have a nastier, less fruitful Earth, more unpleasant for people. No thanks.

For the Climate Discussion Nexus, I’m John Robson and that’s our bleak look into a crystal ball showing a nightmare world with less CO2.