Research indicates that much of this warming is due to human activities, primarily burning fossil fuels and clearing forests, that release carbon dioxide (CO2) and other gases into the atmosphere, trapping in heat that would otherwise escape into space. Once in the atmosphere, these heat-trapping emissions remain there for many years—CO2, for example, lasts about 100 years. As a result, atmospheric concentration of CO2 has increased more than 30 percent above pre-industrial levels. If left unchecked, by the end of the century CO2 concentrations could reach levels three times higher than pre-industrial times, leading to dangerous global warming.
To understand the impact of Carbon dioxide emission on global warming, we must understand the importance of 350, widely described as being the most important number on the planet. Scientists believe that 350 ppm (parts per million) is the upper safe limit of CO2, the maximum amount of carbon dioxide with the planet can support. However, what is alarming is that we exceeded 350 a long time back, in 1990, surpassing the levels predicted by even the most pessimistic models. We are currently at 388ppm, resulting in accelerated arctic warming and glaciers melting. As the levels continue to rise, we are putting ourselves and the planet at greater risk.
While Carbon dioxide is one of the main greenhouse gases, it is not the only one. Human emissions of methane and nitrous oxide together contribute almost half as much warming.
Post last edited on: 2011 April 13
Tags: background, causes