Source: YouTube
URL: http://www.youtube.com/watch?v=WyDmdcPw7Uw
Date: 05/09/2007
Event: Vicky Pope: "By 2014, we're predicting that we'll be 0.3 degrees warmer than 2004"
Credit: YouTube user psevents
People:
[This is an excerpt from a presentation by Dr. Vicky Pope, at the "Climate Change 07" conference at the Barbican in London, on 5th September, 2007.]
Vicky Pope: By 2014, we're predicting that we'll be 0.3 degrees warmer than 2004. Now just to put that into context, the warming over the past century and a half has only been 0.7 degrees, globally - now there have been bigger changes locally, but globally the warming is 0.7 degrees. So 0.3 degrees, over the next ten years, is pretty significant. And half the years after 2009 are predicted to be hotter than 1998, which was the previous record. So again, these are very strong statements about what will happen over the next ten years.
So again, I think this illustrates that, you know, we can already see signs of climate change, but over the next ten years, we are expecting to see quite significant changes occurring.
So, what about the risks of dangerous climate change, further into the future? So [pointing to screen, off camera] this is - that's my attempt to draw a thermometer, on the left-hand side there. And I've just picked up some iconic changes that we might expect at various different temperatures. There are lots of other changes that you could pick here but this is just really to illustrate the point.
So, I mentioned that the temperatures - global average temperatures - increased by 0.7 degrees, and that's illustrated by the blue meniscus there, just at 0.7. When we get to 1 degree, we're already seeing some marine ecosystems suffer irreversible change. And there's already been reports of coral reefs being damaged by ocean acidification, so that's a very real danger that's happening now.
The melting of the Greenland ice sheets - the Arctic is the region where we will expect to see climate change first, and there are already signs of change, in terms of ice melting. Although, because the observations don't go back very far, it's quite difficult to disentangle natural variations from climate change, but we would expect to see the changes first - quite large changes - in the Arctic, because you get strong feedbacks in the Arctic, in terms of temperature - the temperature changes are much bigger, there. As ice melts - ice reflects sunlight, so as it melts and disappears, you've got a darker surface, it absorbs more sunlight and so you get more warming. So you get a stronger warming in the Arctic than you do in other regions.
So, we would expect, by the time we get to 2 degrees, that the melting of the Greenland ice sheets may become irreversible. So, basically, the melting is happening faster than snowfall builds it up again, so it will gradually decrease. If all the Greenland ice melts, that would give rise to a rise in sea level of 7 metres, which is very significant. But we have to bear in mind that this takes a very long time. It takes a lot of heat to actually melt all that ice, and it could take 3,000 years before it melts, but obviously if you set yourself on a train where that's irreversible, you know, that has very dire consequences in the future. It allows you lots of time to adapt, but it makes - it would make the world a very different place.
Once you get to 3 degrees, we're looking at the risk of significant loss of the Amazon rain forest. And in fact, in our model, the Amazon rain forest disappears completely. In other models, it's not quite so dramatic, but nevertheless, this is a very significant area. And it provides a feedback, actually, on the climate, because the rain forest obviously cycles a lot of water. If the rain forest disappears, then you get drying out and you get a feedback on a reduction in climate. You also, if vegetation disappears, if soils are damaged, then not as much of the carbon dioxide that we produce is... [The video ends here.]