Gone are the days when we had to go out of our way to complete simple tasks. With the power of internet, we can now quickly and easily accomplish just about anything right from home. From paying bills, connecting with friends and family, buying goods, or even searching for information – it’s all possible with a few clicks on a computer or mobile phone. No matter what you need, chances are that you’ll be able to find it online these days.
A group of scientists from NASA and other countries used satellites and computers to find out how much carbon is stored in the trees on African land not covered by forests. They counted around 10 billion trees across the Sahara, Sahel, and Sudan regions, which was quite a task! Their research results were published in the journal Nature and everyone can access it – they made it free for everyone to use.
The research showed that there are many more trees growing in Africa’s semi-arid areas than previously believed. However, these trees don’t store as much carbon as scientists thought they would. The team estimated that 0.84 billion tons of carbon is stored among the African drylands.
When it comes to climate change, it is important for us to know how much carbon trees and other plants store because this affects the projections. The amount of time that carbon stays with a plant is something scientists call “carbon residence time”. For things like grasses and bushes, this time is very short since they grow every season. However, trees can hold carbon for much longer because they stay alive for years. To get an accurate reading of how much carbon a place has stored in its vegetation, we need to know exactly what kind of plants are growing there.
African lands contain all sorts of different environments – from grassy deserts with just a few trees to wide open savannahs dotted with trees, and humid places full of trees. Estimating how many trees there are can be tricky in these scattered conditions – scientists sometimes guess wrong on the number. But it’s really important to understand exactly how many trees there are for both conservation efforts and tracking Earth’s carbon cycle.
The scientists at NASA’s Goddard Space Flight Center in Maryland did something really cool – they collected carbon data on every single individual tree across the dry regions of Africa. Something like this had never been done before, as satellite images often got confused by other plants and thought they were trees. Now we can be sure that we don’t over-predict how much carbon there is in Africa’s drylands!
Scientists figured out how many trees there were in semi-arid Africa, so they could figure out how much carbon was being stored. NASA’s Goddard Space Flight Center helped with this.
Carbon moves back and forth between the land, the air, the sea and back. Trees process a type of gas called carbon dioxide which is found in Earth’s atmosphere. They do this process to remove it from the air using photosynthesis, and storing it in their roots, trunks, branches, and leaves. This is why planting more trees is often suggested if we want to reduce increasing amounts of carbon dioxide that gets released into our atmosphere.
Researchers used special computer programs to look through over 326,000 pictures taken by satellites. The pictures were provided by NASA’s Center for Climate Simulation and organized on the Explore/ADAPT Science Cloud. This gave the computer programs the power to understand what they were looking at.
Martin Brandt from the University of Copenhagen collected AI training data by studying 89,000 different trees. His colleague Ankit Kariyaa also at Copenhagen came up with a special computer program that can recognize these trees even in images of Africa’s dry and less green regions.
The scientists decided that trees were anything with a ‘leafy crown’ and a shadow next to it. After this, they asked a powerful computer called the Blue Waters supercomputer at the University of Illinois to count the trees. When they compared what the computer said with what people saw, it was 96.5% accurate in measuring how large each tree’s crown area was.
Scientists have measured the area of a tree’s crown to determine how much carbon is found in its leaves, roots, and wood. A group led by Pierre Hiernaux from the University of Toulouse checked 30 different species of trees to calculate the mass for their leaves, wood, and roots. Afterward, they found out how the amount of carbon relates to the size of the tree’s crown area by using something called Allometry (the study of how living things change with size).
A team of scientists has created an app which lets people view every single tree within a certain area and learn how much carbon it stores. This information could be really helpful to anyone studying the carbon cycle, like scientists and students; people creating environmental policies; and also farmers who want to know the amount of carbon in their fields.
Scientists have studied the carbon levels in individual trees located throughout Africa’s drylands. They published their findings in a research paper named “Sub-continental-scale carbon stocks of individual trees in African drylands” which was released on March 1st, 2023 in the Nature journal. Their main finding was that some individual trees contain higher levels of carbon than found all over the continent!
