The documentary, "An Inconvenient Truth" by former U.S. Vice President and Nobel Prize winner Al Gore has been described as a masterpiece.

Gore's position is that "global warming has started and is here to stay." He asserted that global climate change is strongly interrelated with the energy crisis. If the energy crisis is resolved with alternative energy sources, the serious consequences of global warming may be prevented after all.

Gore stressed that his global warming theory can be corroborated by the different temperature and climate transformation that have been taking place globally.

However, in a report of the Environment & Climate News several years ago, "thousands of scientific experts all over the world have allegedly rejected Gore's hypothesis on global warming."

In fact, the same report stated that at that time, more than 17,000 of these scientists have signed a petition emphasizing that no believable scientific evidence supporting the principle of catastrophic global warming.

A recent research undertaken by Svante Bjork, a climate researcher from the Lund University in Sweden has revealed that as far as global warming is concerned, "simultaneous warming events in the northern and southern hemispheres, have not occurred in the past 20 000 years."

This may yet prove to be another negative response on Gore's controversial conjecture.

The Wall Street Journal came out with reports that Gore countered with an open letter which he published in the New York Times to disbelievers on global warming and compared them to "medieval flat-Earthers."

Andrew Gavin Marshall in his article, Global Warming: A Convenient Lie gathered several theories about global warming which could help the public determine which side to believe.

Claude Allegre, a French scientist has this to say about climate change, "there is no basis for saying, as most do, that the science is settled. Global warming is a false myth and every serious person and scientist says so."

Marshall himself wrote "for those who saw Al Gore's documentary, it was very convincing of its hypothesis that global warming is a man-made phenomenon that has the potential to kill us all and end humanity. After all, the film was filled with graphs and charts, so it must be true. Let's just get something straight here, Al Gore is not a climatologist, meteorologist, astronomer, or scientist of any kind; he is a politician."

For his part, Björck has gone through the global climate archives, which are presented several research publications, and searched for evidence that any of the climate events that have happened since the end of the last Ice Age 20 000 years ago could have generated similar effects on both the northern and southern hemispheres at the same time.

It has not, however, been possible to verify this. Instead, he has found that when, for example, the temperature rises in one hemisphere, it falls or remains unchanged in the other.

"My study shows that, apart from the larger-scale developments, such as the general change into warm periods and ice ages, climate change has previously only produced similar effects on local or regional level," Björck explained.