Global Warming Scientists Dispute Man-made Greenhouse Effects
In February 2007, the Intergovernmental Panel on Climate Change (IPCC) stated in their Fourth Assessment Report that human actions are “very likely” (i.e. with 90% or greater probability) the cause of global warming, indicated by an increase of 0.75 degrees in average global temperatures over the last 100 years. This statement is the result of very tough discussions on a worldwide scale between thousands of climate researchers whether human activity is the main cause of global warming. The results of this discussion were presented to the public in many publications, for instance in Martin Durkin´s documentary “The Great Global Warming Swindle”, presented in March 2007 at UK´s Channel 4. The main message of this production was that man-made global warming is “a lie” and “the biggest scam of modern times.” Martin Durkin and coworkers argue that the scientific consensus on climate change is the product of “a multibillion-dollar worldwide industry, created by fanatically anti-industrial environmentalists, supported by scientists peddling scare stories to chase funding and propped up by complicit politicians and the media”. The documentary showcases scientists, politicians, economists, writers, and others who are sceptical of the scientific consensus on anthropogenic (or man-made) global warming. Some of the scientists, opposing the main stream of greenhouse gas theories, simply argue that it has not yet been ascertained whether humans are the primary cause of global warming or if there are other natural variations responsible for this phenomenon like increased solar activity, cosmic rays or variations in natural climatic cycles. There is also a series of scientists questioning the temperature records used in the databases as temperature differences attributed to the greenhouse effect are reasonable small (fractions of a ºC). The so-called “urban heat island” effect leads to a local warming in more populated areas, showing slightly higher temperatures due to to increased heat generated by cities, rather than a global temperature rise. Anyhow, this argument was confuted by the IPPC, indicating that the effect of the urban heat island on the global temperature trend is no more than 0.05 °C (0.09 °F) degrees through 1990.






