Some new research from the University of Washington and MIT has some bad news for climate deniers, but good news for the climate. For some time, we’ve known that warming is a lot faster in the Arctic than in Antarctica, but we didn’t know why. Climate deniers, of course, seized on this as an argument against climate change, but this study can put that argument to bed.
It turns out that, because they have very different currents, the seas around the poles work very differently. Warmer water moves Antarctic surface water north towards the Arctic, which is then replaced by water from deeper below the surface. This itself is common enough, but most of the time, the water that is brought up is only from depths of a few hundred meters. The water from Antarctica is coming from upwards of two miles down, meaning that it’s never been affected by climate change brought on by human activity, because some of that water hasn’t been near the surface in hundreds, even thousands of years.
We tend to think of a body of water as being largely the same temperature, but the deeper you get in the ocean (or even in large enough lakes or reservoirs) the colder, and more sluggish, water gets. As that water comes to the surface though, it will begin to be affected by climate change, though it will be a while till Antarctic water sees much of a temperature increase.
In the meantime, we know now a lot more about how water circulates around Antarctica, and knowing that, we can make more accurate predictions of how temperatures and climates will change in the future. It also drives home the reality that, despite an overall increase in global temperatures, not every part of the world is affected in the same way, or at the same rate.