Carbon trapped in Cities more than Rain forests
Carbon dioxide is the most prevalent greenhouse gas in the Earth's atmosphere, so reducing production and trapping any existing CO2 is something on the agenda for everyone looking to fight climate change. Conventional ideas for doing this included planting more trees, but a recent study has been looking at intentionally storing carbon in cities as another way to combat global warming.
Galina Churkina of the Leibniz Centre for Agricultural Landscape Research in Germany has been leading a study exploring this concept, examining evidence from several sources or organic carbon that comes from animals, plants, dirt, wood and refuse.
According to their findings, U.S. cities contain approximately 20 billion tons of organic carbon; most of which is within the dirt. Much of this carbon is found under lawns, buildings and roads. An estimated 3 billion tons are trapped within man-made materials the rest reside in garbage dumps and wood building materials. Cities store around one-tenth of all the carbon in U.S. ecosystem; their study will be published in a forth-coming issue of the Global Change Biology journal.
While trapping carbon within cities is a new take on dealing with excess carbon dioxide levels on the atmosphere, planting trees is still a great strategy. Besides the fact that they convert CO2 into carbon with themselves, trees also help to cool cities and reduce the need for air-conditioning; another source of greenhouse gases.
Having more trees and lawns is a great idea, but how the green space is maintained may also cause problems. Fertilizers are typically created using a lot of natural gas and as they break down release nitrous oxide - an even more potent greenhouse gas than CO2! Lastly, fossil fuels are still used to power most landscaping equipment used in cities. Balancing the benefits and drawbacks requires seeing the big picture and not just focusing on potential carbon storage.
Dealing with the current excess amount of carbon dioxide in the atmosphere will take ingenuity and change from the ways that have lead to the problem. Using cities as a means of trapping carbon can be one small step towards getting carbon dioxide levels under control.