Various reasons have been given to justify their disbelief. The sceptics reason that contrary to allegations by advocates, the increase in carbon monoxide in the atmosphere has enhanced wheat production by 50 to 75 percent, vegetables by 51%, and increased vitamin and antioxidant concentration in the produce. According to these detractors, the present increase in global temperatures is due to natural causes such as solar activity, volcanic activity, and so on, and that car and industrial emissions are too insignificant to cause climate change. Other reasons are given mostly in terms of dollars and cents. For instance, one website entitled Global Warming Lies (2010), manned by a webmaster who chose to remain anonymous, cites the $400 billion yearly cause as the major reason for not joining the Kyoto Protocol (the worldwide agreement to significantly reduce carbon emissions). So far the United States is the only country in the world that has continually refused to affix its signature on the agreement (UNFCCC, 2010).
Recently, the spate of cold weather was also cited as proof that global warming did not exist, because the weather was so cold, not warm (Charisse, 2010). To this, advocates have responded soundly, According to Fitzpatrick (2010), the present extended period of cold and snowy weather over North America is actually confirmation that global warming is still happening. Global warming does not mean that the world is getting warmer, but that weather extremes are being experienced in different parts of the globe. Presently, there is an El Nino weather disturbance, the warmer than usual sea surface temperatures over the East Pacific. The phenomenon causes many more storm systems to develop over North America, and energizes the jet stream. Furthermore, the negative North Atlantic Oscillation has created a