Source: BBC Radio 4: Today
URL: N/A
Date: 02/09/2016
Event: John Humphrys on Tambora: 0.7 degree temperature drop "not a huge amount"
Credit: BBC Radio 4
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John Humphrys: Is there any spectacle in nature more majestic than a volcano erupting, more majestic or more terrifying or more destructive? It's 200 years since Mt Tambora in Indonesia erupted, and that was a big one, massive. One of the things it did was kill the summer - they called it the "Lost Summer", and that provided inspiration for poets, including Lord Byron, - here's an extract from his poem Darkness, written in 1816, read by Luke MacGregor from the BBC Radio Drama Company.
Luke MacGregor: I had a dream, which was not all a dream.
The bright sun was extinguish'd, and the stars
Did wander darkling in the eternal space,
Rayless, and pathless, and the icy earth
Swung blind and blackening in the moonless air;
Morn came and went and came, and brought no day,
And men forgot their passions in the dread
Of this their desolation; and all hearts
Were chill'd into a selfish prayer for light...
John Humphrys: Mm. Well, David Higgins is an Associate Professor in English Literature at Leeds University; he's written a paper about the literature of 1816 - we'll talk to him in a minute. First, though, Professor Hazel Rymer, who's a volcanologist, Pro Vice Chancellor at the Open University - tell us about that volcano. It was massive, wasn't it.
Hazel Rymer: It was a massive volcano, yeah, it was about 4 kilometres high and after the eruption, it was only about 2,600 metres high, and it had a hole 7 kilometres across -
John Humphrys: Gosh.
Hazel Rymer: - which was the new crater. And that was over a kilometre deep. So, yeah - it blew its top, literally.
John Humphrys: Literally - and didn't you say that it was a thousand times bigger than some of those Iceland volcanic eruptions we've got so worried about?
Hazel Rymer: Oh, absolutely, yes, yes, yes.
John Humphrys: Thousand times bigger.
Hazel Rymer: Yeah, this was the largest eruption that has occurred in human history.
John Humphrys: What, really?
Hazel Rymer: There was another one 73,000 years ago that almost wiped out the human race, in Sumatra, but apart from that, this is by far - far and away been the largest -
John Humphrys: Bigger than Krakatoa, the one that we all know about.
Hazel Rymer: Yes, yes indeed.
John Humphrys: Much bigger than that.
Hazel Rymer: Yes, yes.
John Humphrys: And the damage it does - obviously we know what - we've seen it for ourselves, obviously, but when all that material goes up, the ash and everything else, goes up into the atmosphere, it just blots out the sun.
Hazel Rymer: Yeah. Well, there were two things, really. So the ash goes up, of course, but that relatively rapidly falls out. The real bad thing that happened in this case was that it was the sulphur dioxide went up very, very high, well over 10 kilometres into the stratosphere, very, very high, forms sulphuric acid aerosols and those go right around the globe, and they had the effect of reflecting the sunlight. So you've got the fact that they - well, they just stop the sunlight coming -
John Humphrys: And so instead of global warming, you got global cooling.
Hazel Rymer: Indeed, yes.
John Humphrys: Really, seriously? I mean, did the temperature really drop?
Hazel Rymer: As far as we can tell, the temperature did drop, over the following summer, by about 0.7 of a degree.
John Humphrys: Well, not a huge amount.
Hazel Rymer: Well, it doesn't sound very much, does it? But any drop at all is significant, in terms of, you know, what it does to the crops growing and everything else. And of course the fact that you haven't got so much sunlight affects growing, anyway -
John Humphrys: Yeah, of course.
Hazel Rymer: - so even if the temperature isn't lower, just the darkness is -
John Humphrys: And David Higgins, it affected poets.
David Higgins: Yes, that's right. Most obviously, Lord Byron, Percy Shelley and Mary Shelley were living with each other in Switzerland at the time, and they experienced this very terrible summer, very sublime weather, and it inspired them to write a large number of texts that simultaneously were concerned with the power of human beings to shape the environment - most obviously, Frankenstein - but also with our vulnerability to elemental forces and agencies that we cannot control.
John Humphrys: Ah, because Shelley wrote, didn't he, "this globe which we inhabit will at some future period be changed into a mass of frost, by the encroachments of the polar ice".
David Higgins: Yes, that's right, he was - read the French natural historian Buffon, who'd theorised that the Earth had started as a fiery ball and was getting colder and colder, over the millennia, and would eventually become uninhabitable. So he writes about, in Mont Blanc, "the glaciers that creep like snakes that watch their prey". And then in Frankenstein - one of the interesting things about Frankenstein is that the creature is much better adapted to survive in Arctic environments than human beings, so there's this anxiety that human beings might be supplanted by a new species that is better able to survive in this icy planet.
John Humphrys: Oh, any parallels for today?
David Higgins: Well, I think there are lots - we're currently living at a time with unprecedented human impacts, sometimes called the Anthropocene, a new geological epoch. And so, on the one hand, we may feel very, sort of, powerful, as a species. But at the same time, those impacts take place within a system that is volatile and unpredictable and involves agents other than the human. So there's simultaneously a sense of our power but also our weakness and vulnerability, and I think that comes across very clearly in the literature of 1816.
John Humphrys: Mm, and are you seeing our modern writers taking account of this, as well?
David Higgins: Yes, I think so, increasingly. There's been a surge of writing in Climate Change Fiction, or CliFi as it's sometimes called -
John Humphrys: No - CLiFi?
David Higgins: CliFi.
John Humphrys: That's terrible!
David Higgins: That's a horrible coinage, isn't it. Also quite a lot of contemporary poets are starting to work on this. I think, you know, nature writing has sometimes been a bit slow to catch up, and sometimes been very focussed on the sort of individual and local rather than these global things, but increasingly nature writers are also concerned with the larger context of global climate change.
John Humphrys: And Hazel, should scientists be as scared? [Hazel Rymer laughs.] If "scared" is the right word. I suppose you don't have your equivalent of CliFi, do you?
Hazel Rymer: Well, we do have our scientific papers, within which we speculate what's going on, and so on. But that there will be another large eruption is absolutely certain, we don't know quite when -
John Humphrys: Is it?
Hazel Rymer: Yes, yes indeed. And there are several volcanoes erupting today, of course, as there are every day, but not quite as large as Tambora.
John Humphrys: So how can you be sure - you've got ten seconds to tell us - how can you be sure that there's going to be another really big one?
Hazel Rymer: Because plate tectonics is continuing to operate, and the Earth is still cooling down, so volcanoes will be the way in which that is expressed.
John Humphrys: But you can't put a time limit on it.
Hazel Rymer: Well, the Earth will eventually cool down, but it's going to take quite some time, yet.
John Humphrys: Why not before Christmas? That'll do it. Professor Rymer, David Higgins, thank you both very much.