Greenhouse gases and climate change Greenhouse Gases and Climate Change Greenhouse gases have been accumulating in the atmosphere since the industrial revolution, almost 250 years ago. Carbon dioxide Carbon dioxide is the main greenhouse gas emitted by human activity. It is responsible for over half the enhancement of the greenhouse effect. The main sources are shown in Table 1. The largest single contributor to emissions from fossil fuels is power generation.
Transport is another major contributor.
The difference between total emissions and the known sinks is described as the inferred sink, which is probably partly due to the extra growth of plants, stimulated by higher concentrations of CO 2 in the atmosphere. The concentration of CO 2 in the atmosphere has increased from about 280ppmv, before the industrial revolution, to 358ppmv by 1994. The concentration of CO 2 in the atmosphere has been measured in Mauna Loa, Hawaii since the 1950s. The results are illustrated in Figure 1, which shows the regular increase in concentration and the accelerating growth rate. The natural carbon cycle influences the rate at which CO 2 from human activity accumulates in the atmosphere.