Statements made by the United Nations Intergovernmental Panel on Climate Change (IPCC) have been used to put pressure on governments to formulate policies in response to the perceived threat of the climate change resulting from a build up of greenhouse gases in the atmosphere. The Kyoto Protocol proposed by the United Nations calls for industrialized countries to cut greenhouse gas emissions by five percent from 1990 levels by the year 2012. The enormity of the perceived economic consequences of this has led to intense arguments between governments over the appropriateness of reduction targets. But the real reason behind the failure to agree on a global climate treaty is disagreement on tradeoffs between the economic and environmental risks involved.
Contrary to the IPCC predictions, global temperature has not risen appreciably in the last 20 years. Most surface temperature data free from the influence of surrounding buildings and roads show no warming. Data from satellites support this. Sea level has been rising since the end of the last ice age, long before industrialization, but historical records show no acceleration in sea level rise in the twentieth century. Increases in carbon dioxide appear to pose no immediate danger to the planet. The gas is not a pollutant.
An understanding of global warming hinges on the answers to certain key questions. Is global climate warming? If so, what part of that warming is due to human activities? How good is the evidence? What are the risks? The task of answering these questions is hindered by widespread confusion regarding key facets of global warming science. The confusion has given rise to several fallacies or misconceptions. These myths and misconceptions, and how they relate to the above questions, are explained. Although the future state of global climate is uncertain, there is no reason to believe that catastrophic change is underway. The atmosphere may warm due to human activity, but if it does, the expected change is unlikely to be much more than 1 degree Celsius in the next 100 years. Even the climate models promoted by the IPCC do not suggest that catastrophic change is occurring. They suggest that increases in greenhouse gases are likely to give rise to a warmer and wetter climate in most places; in particular, warmer nights and warmer winters. Generally, higher latitudes would warm more than lower latitudes. This means milder winters and, coupled with increased atmospheric carbon dioxide, it means a more robust biosphere with greater availability of forest, crops and vegetative ground cover. This is hardly a major threat. A more likely threat is policies that endanger economic progress. The negative effect of such policies would be far greater than any change caused by global warming. Rather than try to reduce innocuous carbon dioxide emissions, we would do better to focus on air pollution, especially those aspects that are known to damage human health.