an autodidact meets a dilettante…

This Aug. 12, 2009, photo shows a section of the vital Dempster Highway linking southern Canada with the Northwest Territories after it collapsed because warming temperatures caused the permafrost below to thaw. Permafrost melting from global warming is causing damage to infrastructure across the Arctic. (AP Photo/Rick Bowmer)

Canto: So what’s on the agenda for 2016 here at the new ussr?

Jacinta: Well I’m hoping we can do a ‘deep dive’, as one researcher likes to put it, on GMOs, another polarising subject, with a few posts, and maybe at least one on Monsanto, the supposedly evil capitalist monster that the anti-GMO crowd love crusading against…

Canto: Good, and I’d also like to focus a bit more on climate change, the ever-developing science of monitoring this complex beast, as well as the clean energy responses.

Jacinta: Including nuclear?

Canto: Well of course I don’t want to shy away from its potential, or its problems.

Jacinta: So no more black holes and cosmic webs?

Canto: I’d love to cover everything, if I had but talent enough, and time.

Jacinta: Yes and I’d like to find time for some philosophy as well, say on the limits of science, if any. But okay let’s get started on climate. I know you’ve been thinking about the ‘Climate Watch’ segment in the most recent issue of  Cosmos, Australia’s most excellent science mag.

Canto: Yes, so while we’re congratulating our leaders (or not) on coming to an agreement re targets for global warming, we need to keep our eyes on the changes already underway, which many have been warning for years might lead to runaway, unstoppable warming.

Jacinta: Feedback loops and cascading effects.

Canto: Precisely, and one of the most serious, because unpredictable, changes we’re witnessing is in the arctic permafrost.

Jacinta: Which presumably is becoming less perma and frosty.

Canto: It’s thawing out, releasing large volumes of methane from the microbes that have been frozen there for many centuries.

Jacinta: And that’s a biggie in terms of greenhouse gases. So why do these presumably dead organisms release methane? I thought all our methane came from cow farts.

Canto: Did you really? Methane is released by rotting organic matter. You have peas in your freezer? Yes? So can you smell them? Very unlikely in their frozen state. So dig out a handful and stick them out in our summer sun. Pretty soon they’ll start to smell. What are you smelling?

Jacinta: Uhh, methane?

Canto: You’re quick. Amongst other gases of course – pure methane doesn’t stink like that. And because methane is such a potent greenhouse gas its release speeds up the thawing process, which could lead to a kind of tipping point, but the extent of this speeding up process, the amount of methane currently being released, and how it will affect the overall warming, these are horrendously difficult values to predict.

Jacinta: And methane’s essentially what we call natural gas isn’t it? CH4? So it’s another carbon-based product.

Canto: Yes, and twenty times more potent than CO2 as a greenhouse gas, according to climate scientists.

Jacinta: And the process we call rotting, that’s actually bacterial, isn’t it? Is it that these microbes release methane, inter alia, the way that we release CO2, after breathing in oxygen?

Canto: You’re talking about methanogens, which are actually archaea rather than bacteria. They thrive in anoxic, or low oxygen conditions, such as wetlands, but also in the digestive tracts of ruminants, indeed in most animals including humans. We release methane when we fart.

Jacinta: Some more than others. So I suppose the permafrost contains all these archaea, or they multiply when it starts to thaw?

Canto: They’re unlocked or reawakened by the thaw, and then, recent studies have shown, they can pump out methane at a phenomenal rate. And there’s a lot of permafrost involved at the moment, in land not under ice, including about half of Russia and Canada, and much of Alaska. They reckon there’s about 1.7 trillion tonnes of carbon trapped in this permafrost, twice the amount of atmospheric carbon.

Jacinta: So how much is likely to be released?

Canto: Nobody really has any idea, that’s the problem. One study has suggested that almost a tenth could be released by 2100, which doesn’t sound like much, but this effect hasn’t been factored in by the Intergovernmental Panel on Climate Change because it’s so hard to calculate – some of the microbes will be methanogens, some will be more liable to release CO2, depending on the local environments created by the thaw. Clearly it’ll be negative though, and will just add pressure and urgency to our plan to keep global warming down.

Jacinta: Yet I thought that the regions you mentioned, those permafrost regions, were full of evergreen forests – the taiga I think is the name. And they’re a carbon sink rather than a source of emissions.

Canto: You’re right, that’s another factor. In fact the taiga is a huge carbon sink, the biggest land sink on earth, but with climate change, the whole permafrost region is becoming less of a sink and more of an emitter, perhaps for the first time. The effects, as I’ve said are very difficult to predict, because the thaw is occurring at different rates, affecting different micro-climates, and with vastly different results even within metres. Being frozen has a uniform, more predictable effect. The thaw unlocks huge varieties of ecosytems – life in all its blooming buzzing confusion.

Jacinta: Well it does sound kind of fascinating in itself, apart from the disturbing effects…

Canto: Spoken like a true disinterested scientist.

permafrost thaw ponds around Hudson Bay, Canada