temporal - just in the mood2share
I gave a talk on global warming at the local community center a few years ago. I showed a Gaussian distribution of NH temperature anomaly for each decade since the 1950s. The mean is getting hotter as one would expect but the variance is increasing also. This means that the probability of an extreme cold event has not changed much since the 1950's and Inhofe will be able to bring snowballs into the Senate chamber long into the foreseeable future. However the probability of an extreme heat events has increased about 10 fold. I looked about the room at a bunch of polite blank stares and I asked if anybody knew what a normal distribution was and nobody knew.
I'm guessing less than 2 or 3% of humans are sufficiently numerate to understand the human condition. Out of that, I don't know how many are ideologically dumbstruck. Milton Friedman certainly had the math skills. It was his libertarian ideology which turned him into an idiot. But we are all prone to ideological bias.
Hansen's paper is extremely dense with information. I doubt anybody, even Kevin Trenberth, has had sufficient time to digest it and assimilate it which calls into question some of the “expert” comments we’ve been reading. What it tells us is that there is a high probability of several meters of sea level rise within 50 years. That would be true even if the paper had some technical flaws, which would be hard to believe given the competence of the authors, including Eric Rignot. In fact, the paper downplays the contribution of the Greenland ice sheet which Greenland specialists like Jason Box are going to question. So on this score I’d guess the paper’s conclusions are as likely to be overly optimistic as pessimistic.
So all we are arguing about is the probability of the timing of the disaster, not its eventuality. And of course, sea level rise is only one concern.
Is 6% enough? I doubt it because sequestering 100 GtC is unlikely and that is the point I thought Robert Callaghan was trying to make at least in the link. We have to stop destroying forests before we can begin to replant them. In an energy starved world I don’t see that happening.
Here is the most salient line: “A sea level rise of 5m in a century is about the most extreme in the paleo record (Fairbanks, 1989; Deschamps et al., 2012), but the assumed 21st century climate forcing is also more rapidly growing than any known natural forcing.”