African nations may be showing the way for climate change control: The Great Green Wall

Roughly a decade ago, one of the most ambitious projects began its long journey. More than 20 african nations have decided to create the largest living object in the planet, a wall of trees with length more than 8000 km that is being seeded in the southern part of the Sahara desert, known as the Sahel. The sheer magnitude of this project is awe inspiring and the goal of this multinational effort is simple. Stop the Sahara desert from advancing. Just like that.

Theories in the paleoclimate field are controversial regarding the age of the Sahara desert. However, the prevalent theory at this point is that the area undergoes a cycle between being a Savannah and desert every around 20000 years. This is caused by the changes in the african monsoon that affects the levels of rain in the area. Sahara is such a vast barren area that most of us tend to believe that it has always been like this. But studies show that the area was grassland just 5000 years ago. So, if the natural conditions are there, an engineered solution can possibly change the pattern of this cycle. Of course, it will not happen overnight and it will not be cheap or easy. But it is doable.

The implications of such an effort are many. First of all, this green wall is going to help prevent floods in the area, since the root system of the trees can limit the erosion of the land and help create living and stable soil. This means that the arable land can become safer for cultivation of the necessary food for these famine stricken areas. This could be on its own a unique achievement. But the benefits do not stop here. This forest could become a climate change factor in itself. The microclimate that a mass of trees creates can have drastic effects on the precipitation levels of the area. A rise in the precipitation levels can also enrich the water reserves, creating the possibility of irrigated land. Given time, the creation of new arable land can be possible.

Of course, the sheer benefits for the economy of the area are obvious and more than significant. Arable land means jobs, food, economic stability and growth. This could transform the Sahel area in more ways than one.

Lastly, planting trees is the most effective way of trapping carbon dioxide, which is considered an important factor for climate change. It always struck me as odd that we only seek ways of limiting carbon dioxide emissions, while we do practically nothing in the way of strengthening the other part of carbon dioxide cycle. We keep aiming at the emissions, but very few efforts have been dedicated to the return of carbon dioxide in forms that do not attribute in the rise of global temperature. And even the few that have been explored are artificial mechanisms of trapping CO2 in small areas, aimed at urban environments that require energy to operate, so in my mind with dubious practical results. The living mass of the trees in the green wall alone can contribute to the binding of 25 % of the total CO2 emissions from Africa at this point. One could argue that economic growth will bring along increased demands for energy and consequently increased greenhouse gas emissions, but a strong economy is more likely to adopt environmentally friendly solutions for energy production. This is more likely to happen in the African continent where the natural resources in fossil fuel are not as rich, while renewable sources are ample.

On another level, Europe is dealing with an issue with people from Africa migrating in larger and larger numbers. The reasons for this are poverty and war. The basis of the economy in most countries of the area at this point is exploiting natural resources for use in the industrial world. This means that sources of income are concentrated in small areas and easily controlled by small groups that fight for control over these resources. People are forced to participate in this cycle or migrate, since there are very little other sources of income. Farmers are vulnerable to natural disasters, since the soil is prone to erosion and flooding. Hence, food sources are scarce and crops are not guaranteed. Famine due to natural disasters is a common problem for the whole continent. However, the transformation of an area from desert to arable land will keep these people where they want to be, in their homeland. Just try and imagine the vast area of Sahara transformed into a green sea, where cultivation of food and pasture is possible. Population would flock there, in an expansion lastly seen during the colonization of North America some centuries before. A brave new world can emerge, transforming the climate and economy in a global level.

The last decades we have been exploring ways, even as thought experiments, for terraforming Mars and other planets. So, it seems extremely peculiar that we have not yet tried to apply this kind of solution to areas of our planet that are currently uninhabitable. The ultimate goal is the creation of a viable ecosystem where economic and environmental sustainability is possible.

So, the simple practice of planting trees in an area that is practically unusable seems to offer a solution in multiple levels. On the one hand, there can be a positive effect on the microclimate of the area and contribution on global ecosystem’s balance. On the other hand, land that was previously barren can now be used for cultivation and financial growth. Lastly, the social problem of migration can be controlled in a way that is beneficial to all parts.

And we can achieve this by simply seeding trees, or if you like, applying an environmentally friendly engineered intervention.



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