March 20th, 2009
|05:47 pm - Global warming|
The biosphere threatened? But that's where all my friends live!
watervole posts a link to this New Scientist map of the world in 100 years time following a 4C rise in temperature.
ALLIGATORS basking off the English coast; a vast Brazilian desert; the mythical lost cities of Saigon, New Orleans, Venice and Mumbai; and 90 per cent of humanity vanished.
Wasn't it considerably hotter than that in the Eocene, and the planet was heavily wooded and supported a massive number of mammals? However, I suppose it is the speed of change is what would cause the problem.
Worth reading the whole article.
I'd have to look at a world map of the Eocene before answering that one. It's very easy to fall into the 'Forest Moon of Endor' trap and assume that an entire planet only has one climatic zone - though a quick check suggests a variety of types in the Eocene which certainly had a lot of forests of different types. It's hard to be very certain as a lot of the articles I'm trying to look at are ones you have to subscribe to. There seems to be a scarcity of Eocene remains in present-day tropical Africa, so it's harder to work out what was there.
One site talks of forests north and south of latitude 15, but not of the bit inbetween (which is a pretty broad swathe of land.) they may have been forested, we simply have no way of telling.
Ocean currents were different during that period (Wikipedia) and that had an impact on the way heat was transferred around the globe. Also, ocean circulation patterns have a bit impact on rainfall distribution.
may have hit the nail on the head when he commented to me that there aren't projected to be any forests because we'll have cut them all down. At the present rate of deforestation that's pretty easy to believe.
One problem is that the situation is only comparable to a degree. Change in the Eocene was rapid in geological terms, but nothing remotely comparable to the rate of change we're getting now.
I'm trying to find more articles to compare the Eocene situation with the present, but am drawing a pretty miserable blank at the moment.
Glacial retreat is a big part of the current problem for countries like India. Once the Himalayan glaciers are gone, the meltwater that feeds rivers like the Ganges throughout the year will become a short seasonal flood. That's clearly a disaster for agriculture. (dams may help, but they in turn lose land for agriculture and can create problems of other kinds, especially in earthquake zones).
I know what you mean about friends. I'm a conservationist because I like people.
I think rate of change is very singificant, because species and cultures can adapt or evolve given time. I hate to think that the beautiful woods I have beeen walking in this week will perhaps be gone soon. I genuinely do hope we are wrong about all this.
|Date:||March 20th, 2009 10:27 pm (UTC)|| |
That is the map that made me go slightly crazy a week or two ago. The government aren't doing anything because THEY WON'T BE IN POWER THEN. THAT IS HOW WEIRD THE GOVERNMENT ARE. They are pretending we need an economy back when we need an ENTIRELY NEW KIND OF SOMETHING. I went to climate change meetings in the hope they would tell me that new scientist were completely overreacting, but amazingly they didn't say that. They said that if we all become carbon NEUTRAL pretty much IMMEDIATELY maybe it'll only rise by 2 degrees, not 4. And that will be better.
I don't know anything about the Eocene, but the difference between now and the very coldest part of the last ice age, was about 6-8 degrees. So it's more than or about half that again, and this time only over a tiny time span that is going to send weather spiralling. Temperature follows carbon in the atmosphere really scarily closely, and carbon has gone COMPLETELY MILES HIGHER THAN ANYTHING EVER SEEN, and in a crazy short time. Generally it's not good.
I don't really understand why the government haven't declared a state of emergency and banned everything. EVERYTHING.
This is how i feel too. Either it's real, in which case everything else is more or less going to go away quite soon now, or it's wrong, and we know nothing.
|Date:||March 21st, 2009 11:51 am (UTC)|| |
Who was it who (quite rightly) said "Prediction is very hard, especially about the future"?
Hopefully we know nothing, and everything will turn out diufferent from what we imagine. I really hope that.
That's the one thing we can be certain of. Predictions about the future are always wrong, usually embarrasingly so. Scientists are about as good at predicting the future as tea-leaf readers. The only difference is that tea-leaf readers don't require millions of pounds of funding for their predictions.
|Date:||March 22nd, 2009 10:36 am (UTC)|| |
True. I do believe that there's now enough proof of global warming to need something doing, but given the number of "the world is doomed" proclamations in my own lifetime, let alone the last couple of thousand years... it's hard to swallow the more virulently specific ones.
I'm old enough to remember the tail end of the "Nuclear War" will kill us all scare, amd I vividly remember Paul Ehrlich solemnly assuring us that we'd all be dead by 1990 because of The Population Bomb. I even remember the great global cooling scare (a new Ice Age was coming any day now and of course we were all going to die).
People like to believe in Doomsday scenarios. They fulfil a deep psychological need. And we need to believe it's all our fault. Either it's because we're sinful and God wil punish us, or it's because of industrialism (which means we're sinful and Nature will punish us). Sadly scientists seem to be as prone to this as anyone else. Anof course these scares mean lots and lots of lovely funding for scientists. You won't get extra funding if you announce that it looks like we're probably not all going to die.