When organizations like CDN are lambasted for crimes against posterity and told our descendants won’t forgive us that they were never born, these critics rarely give us anything concrete against which to test their apocalyptic indictment. Which is awkward because, as we often note, science depends on testable hypotheses (or, as Christopher Hitchens put it, “What can be asserted without evidence can also be dismissed without evidence.”). So here’s a bet for you that can be tested: You can’t tell 1919 from 2019 in… no wait. That’s a different newsletter item. We’re talking about one from the Global Warming Policy Forum: Will the less active sun change the trajectory of global temperature? If it does, then CO2 matters less than some say. If it doesn’t, the sun matters less. And your children’s children can take it to the bank.
The dispute here is, fundamentally, over whether a more active sun warms the Earth. Which is not the no-brainer it might seem because the sun’s total energy output doesn’t fluctuate a whole lot. The supposed effect is more subtle.
First, a more active sun has a stronger magnetic field. Second, that stronger field screens out more cosmic rays. So far there is not much argument. Nor is there much argument that the sun, which was unusually active in the second half of the 20th century, is going into at least one more less active cycle. The point of dispute is that third, some people, including prominently Hendrik Svensmark of the Danish National Space Institute (so yes, he’s a “climate scientist”) and also Fritz Vahrenholt and Sebastian Luning, have argued that because cosmic rays are important in seeding clouds that then reflect heat, an active sun by screening them out contributes significantly to warming and a less active sun to cooling.
Others find these arguments unconvincing. But as with all these matters, in the end it’s not who shouts loudest on behalf of a postulated angry posterity or writes the coolest equations or writes them fastest. It’s whether the evidence fits your theory well or badly. So if we do not see significant warming in the next two decades even as atmospheric CO2 rises, it will become harder and harder to uphold climate orthodoxy. Just as if we do, it will become harder and harder to say no, it’s not true.
Science remains complicated, of course. It’s possible that both the sun and CO2 matter, and you could get a situation in which a less active sun masks CO2-driven warming over a cycle and then it bursts out even more fiercely as the sun revives. But the more linear the connection people claim between CO2 and warming the more troubling a failure to see significant warming is for their theory. And since the alarmist models basically blame all the warming on CO2 and related gases, if another factor is allowed to have had any real importance looking backward it necessarily decreases the “forcing” impact of GHGs going forward.
Regrettably, as the GWPF says, it will take two decades to know whether the next two decades are a lot hotter than the hottest thing ever, or cooler than the models predicted. And obviously we would like to know now whether we need to act decisively within a decade to save ourselves all from the heat-driven collapse of civilization and most ecosystems. But there’s some hope here.
Alarmists have been telling us for years that every year was hotter than virtually every other year “on record” which, as we’ve noted, isn’t as helpful as it sounds given that anything like a reliable direct temperature record starts during the Little Ice Age. And because it’s not really true; in the contiguous United States, which has the best records, last year was an unimpressive 11th out of the last 16. Nevertheless, it will be of some relevance whether 2020 is blazing hot or moderate, especially if the alarmists can avoid some of the more obvious exaggeration of the precision and content of global temperature readings.