The emission of greenhouse gases (GHGs) is associated with a wide variety of economic activities such as coal-based power generation, oil-burning motors, wood-burning stoves, etc. The most common GHG is carbon dioxide. The gases, upon emission, circulate in the earth’s atmosphere and, if their build-up is excessive, prevent sufficient radiant heat from escaping. The result is a slow warming of the earth’s surface and air temperatures. It is envisaged that such temperature increases will, in the long term, increase water temperatures, possibly cause glacial melting, with the result that water levels worldwide may rise. In addition to the possibility of higher water levels (which the IPCC estimates will be about one foot by the end of the 21st century), oceans may become more acidic, weather patterns may change and weather events may become more variable and severe. The changes will be latitude-specific and vary by economy and continent, and ultimately will impact the agricultural production abilities of certain economies.
Greenhouse gases that accumulate excessively in the earth’s atmosphere prevent heat from escaping and lead to global warming.
While most scientific findings and predictions are subject to a degree of uncertainty, there is little disagreement in the scientific community on the very long-term impact of increasing GHGs in the atmosphere. There is some skepticism as to whether the generally higher temperatures experienced in recent decades are completely attributable to anthropogenic activity since the industrial revolution, or whether they also reflect a natural cycle in the earth’s temperature. But scientists agree that a continuance of the recent rate of GHG emissions will ultimately lead to serious climatic problems. And since GHG emissions are strongly correlated with economic growth, the very high rate of economic growth in many large-population economies such as China and India mean that GHGs could accumulate at a faster rate than considered likely in the 1990s.
This is an area where economic, atmospheric and environmental models are used to make predictions. We have just one earth and humankind has never witnessed current GHG emission patterns and trends. Consequently the methodology of this science is strongly model based. Scientists attempt to infer something about the relationship between temperature and climate on the one hand and carbon dioxide concentrations in the atmosphere on the other, using historical data. Data values are inferred by examining ice cores and tree rings from eons past. Accordingly, there is a degree of uncertainty regarding the precise impact of GHG concentrations on water levels, temperatures, and extreme weather events.
The consensus is that, in the presence of such uncertainty, a wise strategy would involve controls on the further buildup of gases, unless the cost of such a policy was prohibitive.
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