Matters of Degrees, Percentages

Did you see the New York Times story on the peer-reviewed study about natural gas leakage that's going to be published soon?

All of those power plants that have been built over the past few decades to take the place of coal-burning plants... The idea of "clean" natural gas as a way to transition toward a lower greenhouse gas world...

Inconvenient reality intervenes. From the Times story:

“It takes as little as 0.2% of gas to leak to make gas as big a driver of climate change as coal, the study found. That’s a tiny margin of error for a gas that is notorious for leaking from drill sites, processing plants and the pipes that transport it.”

And also this:

...natural gas is made up mostly of methane, which is a far more potent planet-warming gas, in the short term, than carbon dioxide when it escapes unburned into the atmosphere. And there's mounting evidence that methane is doing just that: leaking from gas systems in far larger quantities than previously thought.

What this study has done is quantify how little gas needs to leak (0.2%) for the result to be worse than coal — how small the margin of error is. Wow.

After I read that, I listened to David Roberts' most recent Volts podcast, an interview with Ramez Naam called What's next for clean energy and climate mitigation. After they discussed various clean energy details, this part near the end is what made me stop and take dictation:

DR: I think it's clear that even with all the good news about clean energy, it looks pretty clear that we're not gonna hit our 1.5° target that we all agreed on in the UN — not at least through the replacement of fossil fuels with clean energy alone.... What do you do about the rise in temperature in the meantime?

RN: In 2011, when you and I first got into this field, we thought the world was headed for 4, 5 or 6° — and that's the difference between now and the middle of the last Ice Age. That is truly the stuff of nightmares. Agriculture would fail... Maybe the end of human society. So the good news is, we have very likely canceled that apocalypse. If you look at now, in the last 24 months, the most likely outcomes now are 2.1 to 2.4°. We should all celebrate that for a while, because that is a level of temperature that is actually compatible with the world growing richer.

The bad news is, we have missed 1.5°, and I don't know how to say this any more clearly, because there are people who will tell you that we might hit it. The odds of that are minuscule. The remaining carbon budget [to stay at 1.5°] is about 250 gigatons. We're emitting 50 gigatons a year, so that's five years of emissions. So if we smoothly went from 2022's numbers to 0 in 10 years, we'd have about a 50/50 chance of staying below 1.5°. That ain't gonna happen. It's not a thing.

Now the good news is, to stay below 2° is about a trillion tons, about 40 years of emissions to reach 0. That's a stretch — 2062 — but it's not impossible. And 2.5° is more than 2 trillion tons, so if you smoothed out from today to net zero in 2100, you'd have a 50/50 chance of staying below 2.5°. And that is totally achievable.

That's the good news. So what's the bad news? ...Every tenth of a degree matters.  

We're all seeing the effects of the warming we've already incurred, both in the weather we are living with and the political instabilities that are occurring. I think Naam is an optimist about how amenable 2° or 2.5° scenarios are to "the world growing richer," or what those words mean (or for whom).

But it was interesting to get those assessments recorded, nonetheless.