Kate's New and Hot (Week 8)

Too much carbon dioxide...

Hey all,

This week, my new and hot is an article from BBC News, and it's about the polar ocean CO² sink. I actually heard a grad student in one of my anthsci classes talking about this last week, but didn't think much of it until I was browsing news articles today.

Anyways, the earth has two main sources of carbon dioxide absorption, the oceans and the land biosphere. Apparently, they both absorb equal amounts of CO² from the atmosphere (a total of half of all CO² emissions), and as a result, slow down global warming. The problem is that Antarctica's Southern Ocean, which is responsible for some 15% of CO² absorption, has begun to decrease the rate at which it pulls carbon dioxide from the atmosphere. Researchers are blaming a combination of the enormous increase in CO² production in recent decades (40% in the last 24 years), and an increase in ocean winds. Of course the CO² sink can not keep up with our growing output of CO², but increasing winds, which are mixing the ocean waters, have led to the saturation of the surface water with CO². Winds have increased steadily in this region since 1958, and this increase is thought to have been caused by changing temperatures resulting from the depletion of ozone in the area and the recent climate change. Normally, the carbon dioxide is pulled down and stored in the deeper water, but as a result of the wind, the gas is brought to the surface and outgasses into the atmosphere. So instead of absorbing CO², the sink is emitting CO².

The loss of efficiency of the carbon dioxide sinks was expected, but not for another 40 years or so. This is a serious problem because as the surface water becomes super-saturated with CO², it becomes more acidic, harming many ocean organisms, such as coral. You can find the full-text here.