Roy Spencer confesses his deep inner conviction:
- I’m far from a political moderate, but I’ve been tagged as a “lukewarmer” in the climate wars. That’s because, at least from a theoretical perspective, it’s hard (but not impossible) for me to imagine that increasing CO2 won’t cause some level of warming.
- Some level of warming can probably be expected, but just how much makes a huge difference.
- Lindzen and I and a few other researchers in the field think the IPCC models are simply too sensitive, due to positive feedbacks that are either too strong, or even have the wrong sign. But we still believe more CO2 should cause some level of warming.
- If the current lack of warming really is due to a natural cooling influence temporarily canceling out CO2-induced warming, what happens when that cooling influence goes away? We are going to see rather rapid warming return…
But Roy also states that he (and Lindzen) believes that the warming effect of CO2 is smaller than that postulated by IPCC (which is already quite small and smaller in AR5 than in AR4), and thus may well be too small to ever be observed. Roy is not so alone to have this idea as he thinks.
Roy thus can easily imagine a broad spectrum from warming to nothing, but can hardly imagine slight cooling under increasing CO2 like in the present observed hiatus (which he admits is not impossible). A very moderate standpoint, I would say.
I write this as a comment to Roys article since Roy does not want my comments on his blog, but Roy is welcome to comment with hopefully some answer to the title question on this blog.
PS Roy sends the warning::
- The Danger of Hanging Your Hat on No Future Warming
- The Danger of Hanging Your Hat on Future Warming.