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My Favorite Climate Graph

2024-02-09 · explainer · Hank · 5:44 · watch on YouTube

Topic: Science & nature · mode: Explainer

Using the Marginal Abatement Cost Curve, his favorite climate graph, Hank argues that US emissions can fall a long way at zero or modest climate premiums, so direct air capture of CO2, which he saw at an ASU mechanical-tree test facility, is a distraction for now, though falling costs will eventually make it important.

What is said

The parts of the video and what is said in each (★ — how much it matters to the video).

00:00:00 — The direct air capture debate and Hank's view that it is not the thing to talk about now

  • ★★★ Hank thinks he and John should not be talking about direct air capture now, because removing a pound of CO2 costs far more than not emitting one. — 00:00:00 · climate change

00:00:29 — Reading the Marginal Abatement Cost Curve: US emissions peak, abatement at $0, $50, $100 and $200+ per ton

  • ★★ Hank says the graph's abatement axis starts at 5 gigatons, the amount of CO2 the US emits per year. — 00:00:29 · United States
  • ★★ Hank says US CO2 emissions already peaked in 2007 at 6 gigatons a year, a fact that still surprises him. — 00:00:43 · United States
  • ★★ Hank says emissions must go below zero, not just to zero, because already-emitted CO2 stays in the atmosphere and has to be removed. — 00:00:51
  • ★★★ Hank says the curve shows that at a zero climate premium US emissions could fall to 3.75 gigatons a year; only infrastructure-building time and work stand in the way. — 00:01:20
  • ★★ Hank says a $50-per-ton premium brings emissions below half of the original peak. — 00:01:49
  • ★★ Hank says around $100 per ton solar, wind and EVs level off, and weirder options such as zero-carbon synthetic fuels and hydrogen start to make sense. — 00:01:55
  • ★★ Hank says capturing CO2 from the air only makes sense beyond about $200 per ton, a lot of money for a ton of CO2. — 00:02:10

00:02:18 — Focus on cheap abatement; Hank's visit to a mechanical tree test facility and why all designs are uneconomic

  • ★★ Hank thinks a carbon tax of $250 per ton of CO2 would break a lot of things and people would freak out. — 00:02:18
  • ★★★ Hank says there is a lot of good to do right now at a $0 or $50 premium, so we should focus on those things. — 00:02:25
  • ★★ Hank recently visited a test facility for a passive air-capture technology called a mechanical tree. — 00:02:33
  • ★★ Hank explains the mechanical tree: metal and plastic, taking in far more CO2 than a tree; its plates rise, bind CO2 depending on wind, heat and moisture, then are lowered so the CO2 is sucked off and pumped out. — 00:02:48
  • ★★ Hank says a commercial plant would need to do something with the captured CO2: turn it into fuel, pump it underground, or solidify it. — 00:03:17
  • ★★★ Hank says the mechanical tree is one of dozens of air-capture designs, all of them entirely economically infeasible; the technology is at the baby stages. — 00:03:26

00:03:46 — Direct air capture is a distraction today but will become important as costs fall

  • ★★★ Hank says broad public focus on direct air capture is now mostly a distraction, and the idea that we can keep burning fossil fuels and capture the CO2 later is silly because not emitting is far cheaper. — 00:03:46
  • ★★ Hank says physics makes direct air capture hard and expensive: CO2 concentration in the air is low and its molecules are very stable and nonpolar, so it is hard to get them to stick to stuff. — 00:04:15
  • ★★★ Hank predicts direct air capture's cost will eventually fall and, with few other ways to remove existing CO2, it will become important, though not for a while. — 00:04:44
  • ★★ Hank says that is why researchers work on it now, and why the US government and private companies are working with universities on the details. — 00:04:58 · United States
  • ★★ Hank sometimes feels nothing gets done unless he personally focuses on it, but people everywhere are working on problems we don't need to watch, though it's nice to look sometimes. — 00:05:09

00:05:14 — Other people are working on problems we needn't focus on; thanks to the ASU guide; sign-off

  • ★ Hank thanks a guide from ASU's Center for Negative Carbon Emissions who answered his text quickly and showed him the facility. — 00:05:24

In the description and comments

  • ★★ The description says the curve guesses about the present without predicting the future, and omits unproven technologies like advanced geothermal that Hank thinks will likely be very important. (hedged) — video description
  • ★★ The description adds that the curve ignores falling energy costs at sunny, windy times of day, which could substantially change the economics of direct air capture. (hedged) — video description
  • ★ The description asks readers to fill out a survey. — video description

Threads in this video

Where the stories that moved here went next

Mentioned

Central: Direct air capture · Marginal Abatement Cost Curve

Also: Organizations: Arizona State University · Center for Negative Carbon Emissions · Federal government of the United States

Concepts: carbon dioxide · Carbon dioxide removal · carbon tax · climate change · Electric car · fossil fuel · hydrogen · Mechanical tree · solar power · wind power

Places: United States

Only in the description or credits: Environmental Defense Fund

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