Ocean Acidification Just Might Complicate the Climate As Well
Recent research shows that ocean warming just might be even worse than previously thought because it has gone deeper than previously believed but another way in which climate change has been affecting the oceans is by altering their chemistry. Having just read another article about this acidification last week and having taken a chem class or two I was wondering how that might actually have another effect on the climate. To my surprise some information about just that has come up this week, including in ths article from Time.
This article references two different studies, the first of which examines how extensive the effect the changes in ocean chemistry on various forms of sea life might be. Unsurprisingly it’s not good for lots of ocean life and an uncertain effect on others but large disruptions in an ecosystem taking place relatively rapidly are rarely good for anything in the system. If there is a major disruption in the ocean’s life cycle it’s unlikely that it would be good for life on land, IMO. And in another bit of chemical interaction there’s still another problem the Time article describes thusly:
The other Nature Climate Change study—by American, German and British researchers—looked at the effects that ocean acidification could have on atmospheric warming. It turns out there may be some feedback—the researchers found that as the pH of the oceans dropped, it would result in lower concentrations of the biogenic sulfur compound dimethylsulphide (DMS). Why does that matter? Marine emissions of DMS are the largest natural source of atmospheric sulfur. (Manmade sources of sulfur include the burning of coal.)
Sulfur, in the form of sulfur dioxide, isn’t a greenhouse gas. But higher levels of sulfur in the atmosphere can reduce the amount of solar energy reaching the Earth’s surface, causing a cooling effect. (In the aftermath of the eruption of Mt. Pinatubo in the Philippines in 1991, which threw millions of tons of sulfur dioxide into the atmosphere, average global temperatures the two years fell by about 0.5 C.) If acidification decreases marine emissions of sulfur, it could cause an increase in the amount of solar energy reaching the Earth’s surface, speeding up warming—which is exactly what the Nature Climate Change study predicts. It’s one more surprise that the oceans have in store for us.
This reminds me of my reaction when those who call themselves climate change skeptics try to claim that the things we don’t know are so great that we can’t reliably believe that existing science could justify taking action to stop or reduce humanity’s influence on global climate. I wonder why they don’t realize that the unknowns are just as likely to be bad news as good. So far most of the new discoveries I’ve read about in this field haven’t been good news.