When I was at school there was a process called desertification occurring causing increasing desert. Now it seems the opposite is happening. Which might be good. But I wonder is the world getting greener because of the increased CO2 or is it because the ice is melting and that land is getting more green?
Or is this all misinformation and have I been misled/misunderstood?
In: Earth Science
Desertification still happens, it wasn’t just for that few years you were at school. And there is indeed satellite evidence of some regions of the southern sub-Sahara area becoming more green in the past few decades. However, only speculative explanations have been proposed for this so far and the most reliable sources I could find were speculating that it’s due to recovery from drought and improvement in farming techniques, not a global un-desertification process.
This makes biological sense too. The limiting factor for plants growing in deserts is water availability, and water is necessary for photosynthesis. You could increase CO2 levels ten-fold and if the water availability remained the same, plants would continue to grow at the exact same speed. The deserts have been getting drier because of the expansion of the Hadley cells that cause them (equatorial bubbles of air that lose all their water over the equator and then flow away from it as very dry air with no rain to drop), it’s just that this one region has had more rainfall in the past few decades than it had in the earlier photos of the record.
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