The sudden increase in the rate of sea level rise

追加: 2026-05-23

[00:00:00]Sea level rise has suddenly increased.

[00:00:02]We've had satellite measurements going on for about the last three decades and it was thought that over that time rate of rise had been fairly steady at around 3.6 mm per year.

[00:00:13]But as more data have come in and researchers have been analyzing it, they found that there's been a sudden jump around 2012.

[00:00:21]So before then sea level was rising at 2.9 mm per year, now it's jumped up to 4.1 mm per year. Why has this happened?

[00:00:30]The researchers can't be sure, but they think it could be due to the recent acceleration in the rate at which the planet is warming. Uh this in turn could be a result of a reduction in air pollution, especially from China. Some forms of air pollution, such as sulfur, have a cooling effect. That means if you clean up air pollution, the planet warms faster. Since 2016, [music] all the known causes of sea level rise no longer add up to explain what we're observing, the observed total. So that means we're missing something. What are we missing? The researchers can't be sure, but their study suggests that it's the warming of the very deep oceans [music] below 2 km. As that deep water is warming, it expands and that's adding a bit to sea level rise.

[00:01:14]Now, 4.1 mm a year might not sound like much, but if that carries on for a century, that's 0.4 m. In fact, the official projection from the IPCC is that sea level could rise nearly a meter by 2100. Its worst case projection is for nearly 2 m by 2100 and 5 m by 2150.

[00:01:36]Yes, [music] 5 m. The most important thing that everyone needs to understand about sea level rise is that it isn't going to stop. It's going to keep on rising and rising. The IPCC has in fact said that they cannot rule out sea level rise of 15 m by 2300.