Nadine Unger is an assistant professor of atmospheric chemistry at Yale. Is she right when she says:
Deforestation accounts for about 20 percent of global emissions of carbon dioxide. The assumption is that planting trees and avoiding further deforestation provides a convenient carbon capture and storage facility on the land.
That is the conventional wisdom. But the conventional wisdom is wrong.
In reality, the cycling of carbon, energy and water between the land and the atmosphere is much more complex. Considering all the interactions, large-scale increases in forest cover can actually make global warming worse.
Professor Unger goes on to state:
Climate scientists have calculated the effect of increasing forest cover on surface temperature. Their conclusion is that planting trees in the tropics would lead to cooling, but in colder regions, it would cause warming.
Share my angst and my argument with myself below the fold.
Something green and growing absorbs solar warmth and energy and CO2. That solar warmth and energy and CO2 is turned into some sort of sugar and stored. Bingo! Heat and CO2 are conveniently soaked up and not allowed to escape.
Okay. Green growing things exhale CO2 at night. Are the winters of colder regions long nights that load up the atmosphere with CO2?
When I was living in Alburquerque in a small rented house, the neighbor to the north erected a six foot tall concrete block wall because he did not like the look of his neighbors. I knew that damn wall would reflect deadly summer heat back at me so I planted a dense row of very tall sunflowers against the wall, along with shorter and more colorful sunflowers to the south to fill in the spaces between the long stalks, and to soak up the sun and heat -- and hide the ugly wall.
I was very much under the impression that I had done a very smart and scientific thing -- and the goldfinches loved it when the sunflower seeds ripened.
Fine, but according to the Scientific American:
Boreal forests across the Northern hemisphere are undergoing rapid, transformative shifts as a result of a warming climate that, in some cases, is triggering feedback loops producing even more regional warming, according to several new studies....
Larch trees drop their needles in the fall, allowing the vast, snow-covered ground in winter to reflect sunlight and heat back into space and helping to keep temperatures in the region very cold. But conifers such as spruce and fir retain their needles, which absorb sunlight and increase the forest's ground-level heat retention....
The researchers used a climate model to assess the impact if evergreens continued their march northward at the expense of leaf-dropping larch. The Russian boreal forest sits over a tremendous repository of carbon-rich but frozen soil. As the forest cover changes, the permafrost begins to thaw, potentially releasing huge quantities of carbon dioxide into the atmosphere, the scientist said.
Alas, the lowly
larch may determine our human fates:
Larches are conifers in the genus Larix, in the family Pinaceae. Growing from 20 to 45 m tall, they are native to much of the cooler temperate northern hemisphere, on lowlands in the north and high on mountains further south. Larch are among the dominant plants in the immense boreal forests of Russia, Canada, and Scandinavia.
Although a conifer, the larch is a deciduous tree and loses its leaves in the autumn.
Who knew a conifer could be a deciduous tree? All that stuff I learned about trees in the first grade ... I was being lied to!
And, larch wood (see Wiki) is used to build damn yachts! It's a damn billionaire conspiracy!
An additional note about the larch:
The larch was a recurring topic in Monty Python skits.
How fitting.