Varieties of Carbon - Black to Green

from article published in Pacific Standard

Brown carbon: Brown carbon is a light-absorbing particle in the Earth’s atmosphere that has the unique characteristics of both cooling the planet’s surface and warming its atmosphere. It was originally distinguished from black carbon in a 2006 report by M.O. Andreae, who has a doctorate in oceanography, and A. GelencsÄr, a chemist. Research published in 2008 by Arizona State University professor Peter Crozier suggests that this nanoscale atmospheric aerosol species is abundant in the atmosphere over East Asian countries and should be explicitly included in models of radiative forcing (the gap between energy radiation reaching the Earth and that leaving through the upper atmosphere).

Green carbon: Green carbon is the carbon that is stored in terrestrial ecosystems such as forests, pastures and soils. This carbon can be released into the atmosphere through deforestation and fire. The U.N. Framework Convention on Climate Change noted in a 2008 report that increasing green carbon stores through reforestation and preservation efforts has great potential to combat global warming.

Blue carbon: Blue carbon is carbon that lives in the world’s oceans. An estimated 55 percent of carbon in living organisms is stored in mangroves, marshes, seagrasses, coral reefs and macro-algae. This carbon is cached for millennia, unlike green carbon, which may be stored for decades or centuries. A new report from UNEP, The Food and Agriculture Organization, and UNESCO’s Intergovernmental Oceanographic Commission highlights the alarming fact that blue carbon ecosystems are being degraded five to 10 times faster than rainforests. Coastal ecosystem services are valued at $25 billion per year — they provide vital nutrition for close to 3 billion people.

Black carbon: Last but not least, black carbon is the carbon formed through incomplete combustion of fuels — essentially soot. It is the most widely discussed form of carbon, and some scientists suspect it is second only to carbon dioxide as a contributor to global warming. Black carbon can be reduced through the adoption of clean-burning technologies.