Why, we were just telling scary stories – say the climate-doomers
For some reason, Now It Can Be Told:
You’ve probably never heard of the term “RCP 8.5” — the highest-emission scenario used by climate scientists to project the planet’s future. But if you’ve read about climate change, you’ve seen the numbers and nightmarish outcomes it produced: 4°C of warming by 2100, sometimes 5°C, sea level rising multiple feet, parts of the planet too hot for humans.
Those numbers shaped a decade and a half of climate journalism, including a lot of my own when I covered climate change at Time magazine. I didn’t always know — and didn’t always communicate — that the scenario behind the most apocalyptic, attention-getting findings was largely an attempt to imagine how bad things could get, not a true forecast. But I wasn’t alone. RCP 8.5 was a frequent background presence in climate journalism.
So are we to conclude that author Bryan Walsh sometimes did know and yet failed to communicate that he was writing the equivalent of a Hollywood script?
As for why he’s telling the tale now, it’s a domino effect:
Last month, though, the scientists who built that scenario formally retired it. In a paper published in Geoscientific Model Development, Detlef van Vuuren and more than 40 co-authors eliminated RCP 8.5 from the scenarios that will feed into the Intergovernmental Panel on Climate Change’s (IPCC) Seventh Assessment Report, which is due in 2029. Based on falling clean-energy costs, climate policy, and recent emissions trends, the highest-emissions pathway had become, in their words, “implausible.”
Walsh still says things will be bad, just not as bad. But why would we trust that prediction?
Was RCP 8.5 ever realistic? One camp of experts, led by climate scientist Zeke Hausfather and energy modeler Glen Peters, argues that RCP 8.5 was plausible in 2011, but was taken off the table by genuine policy and technology progress. The other camp, led by Roger Pielke Jr., argues that the rate of global decarbonization has been roughly linear for decades. That would mean we didn’t actively avoid RCP 8.5; it was just never realistic to begin with. Both camps agree on what counts, though: RCP 8.5 should be gone, and the planet is still on track to warm between 2.5° and 3° by 2100.
Walsh seems to be saying, in most of the article, that if we could predict the policy we could predict the climate. But I have always thought that’s a case of hubris. There are too many variables and too many unknowns interacting in too complex and too poorly-understood a fashion. And that’s even if you assume that scientists and journalists are always acting in good faith, which is – as they say – somewhat implausible.
The models were never falsifiable; that is, their theories cannot be subjected to the usual scientific method of theory, test, review results, revise theory if needed. We had an epic discussion about this a few years ago with an old friend, a top-tier researcher in space physics. My husband, with degrees in physics and electrical engineering, kept saying, “But, [friend], what about the scientific method?” She just kept saying, “They’re experts and they have models.”
Ah, modelers; groundwater flow modelers, contaminant fate and transport modelers, excess cancer risk (for humans) modelers projecting from now to a thousand years into the future for the cleanup of radioactive waste. Hubris? Science? Not sure but very expensive. Good thing they figured out that there was not enough money in the world to safely dig up the underground tanks and associated piping where I work. Start with removing and treating the waste (make glass or grout); that should be done by 2070. Long after I’ve passed, become a Norwegian Blue.
Climate change modeling? Much, much farther removed from reality than the models above IMO.
Chalk up those costs to stoping totalitarian fascists and totalitarian communists. Temporarily anyway. But Iran having a nuke, what about my gas price!
Yup. The United Nations IPCC and their RCP X.Y scenarios have been trending downward in alarmist temperatures for a long while now. I’m surprised they are still as high as 2.5 to 3 degrees.
Aside from the general outrage about projections that were serious alarmist BS and that their idiots (think Carol Browner) would thump the podium with the smoke screen “peer reviewed science!” there are two things that really bug me about this.
1) neo calls it hubris, but yes… There are definitely going to be complexities that they just don’t understand well. The one I focus on are the various feedback effects that could greatly reduce the temperature increase. The modelers invoke feedback as a mechanism that makes things worse, which is possible. But it is just as possible that the dominant feedback mechanism(s) make things much better.
For example, for a while some claimed that the flora biosphere sucking CO2 out of the air had no feedback effect. Their concept is that dead plant life sitting out in the open air will decay and release its carbon back into the air, which can happen. But much of it won’t, as they now understand. Yes, plants can sequester carbon.
I don’t know if it is a practical time scale, but erosion of rock and earth also sequesters carbon out of atmospheric CO2.
2) The flora biosphere LOVES the extra CO2 that we now have in the air because of our fossil fuel consumption. Tens of millions of years ago, the atmospheric levels of CO2 were roughly ten times higher than now. Plants today are essentially carbon starved, though a bit less than they were 100 years ago. Crop production everywhere is higher now compared to 100 years ago.
How often do you hear about that?