Last year in March, I relocated from Detroit back to Pune. We put on our thermal wear, jackets, gloves, and such winter paraphernalia to brave Detroit’s sub-zero temperatures and snow, on our way to the airport. In the stopover at Amsterdam, we removed all that, and proceeded to finally land in the blistering summer heat in India. Well, I realized that I’d better warm up to gear for this!
We’re all concerned about global warming. How India will deal with it is a different story altogether.
As a start, we need to educate ourselves. So here’s something interesting I discovered:
Q. Can planting a tree stop the sea level from rising and the ice caps from melting?
A. It depends. A new study says that it depends on where the trees are planted. It cautions that new forests in mid to high latitude locations could actually create a net warming.
In the first study to investigate the combined climate and carbon-cycle effects of large-scale deforestation in a fully interactive three-dimensional climate-carbon model, scientists from Lawrence Livermore National Laboratory found that global forests actually produce a net warming of the planet.
Forests affect climate in three different ways: they absorb the greenhouse gas carbon dioxide from the atmosphere and help to keep the planet cool; they evaporate water to the atmosphere and increase cloudiness, which also helps keep the planet cool; and they are dark and absorb a lot of sunlight, warming the Earth. Climate change mitigation strategies that promote planting trees have taken only the first effect into account.
Afforestation has been promoted heavily in mid-latitudes as a means of mitigating climate change. However, the study shows that it doesn’t work. The albedo effect (the process by which less sunlight is reflected and more is absorbed by forest canopies, heating the surface) cancels out the positive effects from the trees taking in carbon.
So what can India do? In his inimitable style, Swaminomics offers a refreshing perspective:
Now, if all the world’s trees are cut, Bala’s model shows that the concentration of carbon dioxide in the atmosphere will double by 2100. A disaster, you might think. Yet, the model shows that global temperature will actually fall by 0.3 degrees Celsius.
How can the world get colder despite double the carbon emissions? The model shows that deforestation will heat up the tropics, but the albedo effect of snow reflection in high latitudes will produce a huge cooling effect. On balance, the cooling albedo effect will exceed the warming effect of doubling carbon in the atmosphere.
A more important implication is that the world should seek to increase the albedo effect, not just aim for carbon reductions.
And how can India increase the albedo effect? Use white paint.