“The 4°C scenarios are devastating: the inundation of coastal cities; increasing risks for food production potentially leading to higher malnutrition rates; many dry regions becoming dryer, wet regions wetter; unprecedented heat waves in many regions, especially in the tropics; substantially exacerbated water scarcity in many regions; increased frequency of high-intensity tropical cyclones; and irreversible loss of biodiversity, including coral reef systems.
“And most importantly, a 4°C world is so different from the current one that it comes with high uncertainty and new risks that threaten our ability to anticipate and plan for future adaptation needs.”
The above comes from that well-known bunch of hippies, the World Bank, who add that “4 degrees Celsius… is what scientists are nearly unanimously predicting by the end of the century, without serious policy changes.”
“Turn Down the Heat: why a warmer world must be avoided” from The World Bank.
I think it is now too late to keep the global rise to under 2°C. The way the human world is, our political structures, mean we just can’t get organised in the ways we need to in the right timescale.
Sure, some things we know will happen, like coastal inundation – and some countries may disappear, but all the rest? Maybe. It’s the uncertainty that’s the big thing, we’ve no idea what will happen, especially if the climate, or some parts of the environment, flip into a new steady state, such as permanent alterations to the jet streams or ocean currents. Nobody knows. It is all happening a lot faster than predicted, and 2013 could be a very ‘interesting’ year as La Nina (probabaly) oscillates back to El Nino, and all that heat energy stored away in the oceans, which have kept global temperatures lower, come back into the system. Scary or interesting, or both. Part of me is pretty worried, part wishes I was younger so I could be around to see it all happen. Whatever ‘it’ is.
I’m fascinated by the idea that climate change might make parts of the world effectively uninhabitable, that we might have to withdraw from hurricane coastlines for example. Or that the antartctic might turn into tropical jungle, as it was about 65Mya.
It is just plain interesting from a sort of remote godlike perspective. And of course far bigger changes in average temperature, up and down, have happened in the past. But the speed of the change will make it an appalling tragedy in human terms, specially in places where life is already pretty precarious like much of Southern Africa.
We don’t live in a world where there’s spare land to move into when one bit gets uninhabitable, or a world where people are free to move across frontiers (in fact, when the going gets tough, the frontiers get less permeable). So I don’t really think we can allow ourselves to sit back and observe this as an interesting natural phenomenon. Particularly as we live in the part of the world that’s mainly caused it, while other parts of the world are the ones who will cop it worst.
That’d be a bit like a farmer taking all the water out of a stream to irrigate his crops, and then sitting on his balcony and interestedly watching his neighbours’ crops die.
It’s too late to stop, but it’s not too late to slow it down.