Small comfort

One of the scariest parts of climate science is that various amplifying feedback effects that have come into play, and will do so more as the planet continues to warm. These feedbacks are almost certain to both accelerate the warming of the planet, and to make it continue long after humans have reduced or eliminated our societal carbon emissions. These amplifying feedbacks are why we know that barring nigh-miraculous new technology to pull carbon out of the atmosphere, the planet will continue warming for generations to come.

Fortunately, amplifying feedbacks are not the only responses to a warming climate. One suppressing feedback I heard about a while back is from the increasing number of icebergs breaking off the Antarctic and Greenland ice sheets as they melt into the ocean. The icebergs have a fertilizing effect on the water around them, increasing algal growth, and pulling CO2 out of the atmosphere. It’s not much, but as long as we’ve got ice sheets falling into the ocean, it’s going to keep capturing just a little more CO2 than would be captured without them.

New materials from NASA indicate that, as expected, the warming of the Arctic has had a “greening effect” on northern land masses. This means more photosynthesis, which means more CO2 being captured and stored as plant matter. It’s not clear how big of an effect this will end up being, or how it will compare to loss of primary productivity in other areas due to drought, but it will be some help in slowing the increase in greenhouse gas levels from a thawing, rotting permafrost, and so it will buy us just a little bit more time to get our act together.

Image shows a satellite representation of Canada and Alaska, with some areas shaded in green, particularly in northern Canada. Some areas are also shaded brown. The green indicates an increase in plant growth, and the brown indicates a decrease.

Using 29 years of data from Landsat satellites, researchers at NASA have found extensive greening in the vegetation across Alaska and Canada. Rapidly increasing temperatures in the Arctic have led to longer growing seasons and changing soils for the plants. Scientists have observed grassy tundras changing to scrublands, and shrub growing bigger and denser. From 1984-2012, extensive greening has occurred in the tundra of Western Alaska, the northern coast of Canada, and the tundra of Quebec and Labrador.
Credit: NASA’s Goddard Space Flight Center/Cindy Starr


  1. StevoR says

    Small comfort indeed. The last gifts of dying ice. It won’t buy us much time will it?

    We’ve already had – and wasted so much time. We still are, sadly,

    Still, this is something and is good news.

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