The Climate Change Crisis
Humanity is facing a crisis never seen before in the history of the earth: climate change due to rising levels of greenhouse gasses in the atmosphere. But where are all those excess greenhouse gases coming from? The answer is (mostly) the burning of fossil fuels. While nothing is truly permanent, carbon can be stored in fossil fuels for millenia while the carbon stored in plants is released back into the atmosphere after a few decades when the plants inevitably die and decompose. For the past few centuries, humans have been extracting these semi-permanent pools of carbon and putting them back into the carbon cycle.
The effects of climate change may not seem to affect you directly because of modern technology, but Nicholas Stern – professor of economics and government and chair of the Grantham Research Institute on Climate Change and the Environment at the London School of Economics – predicts that climate change could have an economic damage of up to 20% on world GDP.
Where do Fossil Fuels Come From?
Fossil fuels are deposits of organic materials that have been buried and exposed to the heat and pressure of the earth’s crust to form combustible fuels. These organic materials are made of decaying plants and animals and are converted to oil, gas, and coal over millions of years. However, if these organic materials are burned, eaten, or otherwise decomposed, the carbon is not able to fossilize and it re-enters the carbon cycle.
So it seems to me, that the only way to replenishing these pools of carbon that we’ve been so eagerly consuming, is to consiously and systematically kick-start the process of fossilization of organic materials. One possible way of doing this is through the harvesting and storage of wood.
Wood Harvest and Storage for Carbon Sequestration
In 2008, Ning Zeng – from the Department of Atmospheric and Oceanic Science and Earth System Science Interdisciplinary Center at the University of Maryland – proposed a new way to sequester carbon more permanently. Zeng suggests that burying or otherwise storing wood in ways that prevent decomposition, we can effectively lengthen the time that carbon is removed from the carbon cycle. By collecting deadwood and selectively cutting un-productive trees, and burying them in trenches, abandoned coal pits, or above ground shelters, we are able to store the carbon indefinitely or until we find a better use for it.
Zeng calculated that, with all the tropical, temperate, and boreal forests of the world combined, there is enough tree growth to store 10Gt (or 10 billion metric tons) of carbon every single year. There is even a one-time pool of deadwood on the forest floors to store 65Gt of carbon! However, this is an idealized model and once we’ve accounted for other land use, forest conservation, accessibility, and other wood use, the potential is much less.
The Cost of Action VS. The Cost of Inaction
It is estimated that at $50/tC, $100 billion is needed to sequester 1Gt of carbon. This is approximately 0.1% of world GDP – a small price to pay compared to the potential 20% loss due to the effects of climate change.
Other Benefits of Wood Harvest and Storage
In combination with the reforestation and controlled deforestation industries, wood harvest and storage has the potential for many benefits to the ecosytem. Firstly, storage of deadwood and selective cutting can help prevent forest fires which are responsible for billions of tons of carbon entering the atmosphere every year. Secondly, it can prevent damages from storm blow downs and insect outbreaks from rotting wood. Lastly, each gigaton of carbon that is stored in this way will provide 400,000 people with green industry jobs.
Next Challenges to Overcome
While this method of carbon sequestration is promissing, there are still some challenges we need to face before it can be used worldwide. For example, we need to consider the habitat loss that will come from removing deadwood and select trees from forests. The removal of these organic materials will not only store carbon, but also other vital nutrients like nitrogen. Luckily, there is 10 times more nitrogen in leaves than in wood so we can mitigate this issue by being very selective of what we bury. The biggest problem then is the disturbance to the forest floor and the soil. While more research is needed, the harvesting and storing of wood can be an effective method for carbon sequestration if used in harmony with the natural processes of the world’s forests.
