You can debate the causes all you like, but the evidence that our planet is warming up is unequivocal. One of the big effects of a warming Earth will be rising sea levels – due to melting ice caps and the fact that as water warms up, it expands. As if sea level rises weren’t bad enough already, new research suggests that scientists greatly underestimated the amount they would rise – by 30% or more. Oops.
So how did they make such a big miscalculation? it’s all down to something you wouldn’t really think about normally – dams and reservoirs. Over the last century a huge amount of water that would normally be in the sea has been trapped on land by tens of thousands of dams and reservoirs.
In fact, the total amount comes to some 2600 cubic miles – imagine a box a mile wide, a mile long and a mile high- then imagine 2599 more. It’s a massive amount.
All this water trapped on land means that the recorded sea level rise over the last few decades has been less than what it should have been. But wait a minute… surely it’s good if sea levels won’t rise as much, isn’t it? Erm, I’m afraid not. The problem is that construction of dams and reservoirs has been scaled back a lot in recent years, meaning that any sea level rise from now on will actually make the sea level rise a lot more than scientists predicted.
Most of us don’t need to panic – yet. But by as soon as 2100 major cities like New York and London could be permanently flooded unless we do something about it. I don’t want to sound like a scaremonger, but this really is an issue of life and death for millions of people and billions of animals around the world. You’d have to be pretty foolish to say that global warming isn’t at least partly caused by us humans. Do something great with your life – try to save the world.