By now, we’ve been well taught to view the steady decrease of Arctic ice as a bad thing; and for good reason, it is. But by now, I also hope that I have been able to teach you that, when dealing with the climate, nothing is simple. If that lesson has managed to make it through, then this latest piece of “good” news is going to be very interesting.
According to two separate research groups, new evidence supports the possibility that the disappearing Arctic ice is a good thing for the planet.
As the polar ice continues to melt, a new carbon sink is apparently opening up. Kevin Arrigo and colleagues at Stanford University studied satellite data collected between 1998 and 2007, and found that the quantity of phytoplankton had changed during that period. Phytoplankton produce chlorophyll which gather energy from the Sun, and digest carbon. Subsequently an increase in phytoplankton would mean an increase in carbon sequestration.
So, theoretically speaking, the less ice there is in the Arctic, the more phytoplankton there would be, and the longer the ice was gone, the longer the phytoplankton would have to sequester carbon. In some areas observed, production of chlorophyll was increased more than three-fold.
Thankfully, this is not a method that scientists are going to be recommending anytime soon. Ken Denman of the Canadian Centre for Climate Modelling and Analysis warns that this burgeoning carbon sink will only ever have a very small impact on sequestering human carbon emissions.
According to the research, between half and a quarter of the carbon soaked up by the phytoplankton is actually stored at the bottom of the ocean. This equates to only about 160 million tons of carbon each year and, according to Arrigo, “Given the current rate of human emissions, that would only account for 0.7% of total annual emissions.”
“When you look carefully at the amounts involved, they just are not significant relative to the massive amounts of CO2 that we are and will be putting into the atmosphere,” agrees Denman.
credit: Billogs at Flickr under a Creative Commons license
More on the Arctic from the GO Network
Arctic Breakup Growing Each Week
The Arctic Becomes an Island, Hurting Wildlife
The Arctic Oil Rush and My Misgivings
It would be interesting to compare the increased CO2 absorption of the phytoplankton with the effect of the decreased albedo (less reflective ice, more dark oceans absorbing sunlight). My guess is that the decreased albedo would have a far greater effect, in which case the melting of the Arctic would indeed be bad.
Very interesting, Joshua: I hadn’t heard this one yet. And your starting point — “when dealing with the climate, nothing is simple” — seems like a good argument against geoengineering fixes for climate change.
Every time someone starts talking about “solving” global warming by seeding the oceans with iron or spraying sulfur dioxide into the air, I think about all the unexpected and unintended possible consequences. Geoengineering fixes, to me, seem to promise a simple solution to a problem that is anything but.