How Do We Know that the Atmospheric Build-up of Greenhouse Gases Is Due to Human Activity?
The final line of evidence comes from the geographic pattern of carbon dioxide measured in air. Observations show that there is slightly more carbon dioxide in the northern hemisphere than in the southern hemisphere. The difference arises because most of the human activities that produce carbon dioxide are in the north and it takes about a year for northern hemispheric emissions to circulate through the atmosphere and reach southern latitudes. Carbon dioxide is released to the atmosphere by a variety of sources, and over 95% percent of these emissions would occur even if human beings were not present on Earth. For example, the natural decay of organic material in forests and grasslands, such as dead trees, results in the release of about 220 billion tons of carbon dioxide every year. But these natural sources are nearly balanced by physical and biological processes, called natural sinks, which remove carbon dioxide from the atmosphere. For example, some carbon dioxide dissolves in sea
Related Questions
- How do we know the warming is a result of the buildup of Greenhouse Gases in the atmosphere from human activity, and not the result of natural climate variability or some other natural cause?
- Are the Increases in Atmospheric Carbon Dioxide and Other Greenhouse Gases During the Industrial Era Caused by Human Activities?
- How Do We Know that the Atmospheric Build-up of Greenhouse Gases Is Due to Human Activity?
