Wires, etc: New survey sees bad news in Arctic warming: Melting soil will add tens of billions of tons of methane to greenhouse Earth
Time Magazine‘s Bryan Walsh had a good way today to put into context a new journal report that stokes the long standing fear of a significant new source of greenhouse gases – the warming soils of the arctic tundra and boreal zones. He writes, despite last week’s somewhat calming report on a possibly smaller range of climate sensitivity to greenhouse forces, that overall “most of the science on climate change is dire and getting direr.”
The news comes via Nature. It is not from a new round of research but from a commentary, or essay, by researchers who fear an aggregate message from polar research has not gotten sufficient appreciation. They surveyed a few dozen old Arctic soil hands on what they expect in coming decades (each of whom is listed as an author of the commentary, as part of the Permafrost Carbon Network). Trouble, we got trouble, they said. You know what? A diligent journalist could have done that. But, truth be told, it has more impact when done by scientists and published in a prestigious research journal. Surveys say scientists enjoy tons more public respect than do journalists.
At AP the prolific Seth Borenstein jumped on the news and gets all the numbers and the the reason they induce anxiety. His lede however misleads on the science behind those numbers. He refers to massive amounts of greenhouse gases trapped below thawing permafrost that are very likely to seep into the air. Well. Give me a paragraph or two to dig into that assertion.
The gases are not below the permafrost. They are not trapped either. Most of the methane and carbon dioxide, far as I know, does not even exist yet. The ingredients are in, not under, the permafrost. In fact, as the frozen zone extends down quite a way below the topsoil, most of the permafrost presumably is below the zone that is starting to look like a compost bomb.
What does exist is a great quantity of dead plant debris – soil organic carbon as they call it in the trade. It’s been building up for millennia, like peat in a bog, but only the top few inches or so thaw out each summer. The feared scenario is that as the melt zone reaches deeper into this stew, microbes will proliferate in the newly habitable territory and eat all the organic goodies that they can. Waste products include CH4 and CO2. Borenstein – a highly reliable reporter by the way – does get into his story eventually that the gases will come from decaying plants. But he again says they are stuck below frozen ground. Strictly speaking, the plant debris is stuck IN it. Gad, sorry to be so tedious. It does seem useful to get straight the technical facts that are behind the important facts on why the news matters.
It’s an easy mistake to make. Walsh too, at Time, says billions of tons of methane are trapped in the Arctic. Unless he was thinking of methane clathrates, which I don’t think he was, that should be billions of tons of organic matter.
Other stories:
- Fairbanks News Miner – Jeff Richardson: New estimate boosts permafrost contribution to climate change ; Nice job. Says thawing soil releases CO2 and methane. That is enough to make the point without declaring they are stored in frozen soil.
- AFP – Permafrost loss worse climate peril than thought ;
- Bloomberg/Business Week – Alex Morales: Permafrost Thaw May Emit More Than Deforestation, Study Says ;
- Alaska Dispatch – Doug O’Harra: Will thawing Arctic permafrost speed global warming? ; Good ambitious job. However, the story appears to make the thawing Arctic and resultant gases a possible cause for an Arctic warming of 3.5 F in this century. It appears that the commentary itself has the cause and effect the other way around: Arctic warming, as part of overall global warming, will be the driver of additional release of greenhouse gases. A positive feedback to be sure, but this piece needed to explain it more clearly.
- PostMedia News via Vancouver Sun – Margaret Munro: Melting permafrost adds to risk ;
- Telegraph (Australia) – Malcolm Holland: Thawing permafrost releasing more carbon ;
Grist for the Mill:
University of Alaska, Fairbanks, Press Release ; University of Florida Press Release (which spells out explicitly how the soil carbon becomes CO2 and methane); Permafrost Carbon Network ;
- Charlie Petit
