But can trees store enough carbon to buy us time to act on climate change?
A recent paper said 0.9 billion hectares could lock up 205 gigatonnes of CO2. Including land-use change, such as forests being cleared for farming, but the research was criticized because some think the research makes it seem like trees can do more than they can, exaggerates the amount of usable there is, and how much carbon could be stored. In response. A more feasible amount of CO2, it is claimed, could be 3 to 4 gigatonnes a year.
However, the research has prodded Shell Oil to spend $300m over 3 years on re-afforestation to generate carbon credits for itself and others. Whether this can make a real dent in climate change is another matter. Emissions have to be cut as well, and trees have to be planted at the right place and time. The species also have to be suitable for the climate and the soil where they are planted. The subject is very complicated owing to the huge variety of, say, oaks, birches and other species.
In order to lock up CO2 for centuries local people have to support the effort, understand the value of trees, have a say when and where the trees are planted, and protect the trees once they are planted. There is an idea that there is lots of underused land, which is a myth.
Lastly, if the CO2 locked away is to be accounted for properly, we will need to monitor reforestation for a long time. That is tricky. Deforestation is easy to spot – satellites show areas turning from green to brown. But they find it hard to detect new trees, which for the first few years will be tiny saplings hard to discern from space. Higher resolution images may help.
Meanwhile de-forestation is getting worse. Between 2014 and 2018 the world has lost forests the size of the whole UK , especially in the Amazon and Australia (Adapted from an article New Scientist 29 Feb 2020).
My comment: We are talking about nothing other than mankind’s continued peaceful and pleasant life of the planet, because there is no other suitable nearby planet to evacuate to. There are far too many people who claim this is all a lefty, made-up fuss, just as corona virus is a “short interlude” and will be over when the weather warms. How do we get our neighbours on the same page for the sake of our children and grandchildren? Repeated storms, fires, and medical emergencies beckon.