According to the UN Intergovernmental Panel   on Climate Change, global temperatures have risen by approximately 0.6degC in the past century, caused mainly by emissions of greenhouse gases produced by human activities,such as  the  burning  of  fossil  fuels  and  deforestation.Temperatures are to increase between 1.6degC and 5.8degC in the next century, accompanied by sea level rise and an increase in the frequency of extreme weather events. The best available evidence suggests that climate changes since the 1970s may already be causing over 150,000 deaths annually, and that greenhouse gas emissions would increase disease burdens  in  the  coming  decades.The  risks  are concentrated in the poorest population, who have contributed least to the problem. The Kyoto Protocol   is signed by 128 nations,and commits the participating industrialized countries to cutting emissions of greenhouse gases by over 5% below 1990 level by the period of 20082012. "Over 600 thousand people died in weatherrelated disasters in the 1990s.Temperature and rainfall influence the rates of diseases and infections including malaria,and malnutrition,which together cause over 3.5 million deaths a year.The Kyoto Protocol is the first step towards protecting the climate system,which exerts such a strong influence on our health",said Dr Kerstin Leitner,Assistant DirectorGeneral for Sustainable Development and Healthy Environments. While acting to reduce greenhouse gas emissions, it is also essential to protect vulnerable   communities from the effects of climate changes.WHO works to promote measures such as protection from malaria and other climate sensitive diseases, and reliable access to clean water and sanitation, for people  in the  most vulnerable developing countries.Increasing disease control efforts will also help to protect current and future generations from the impacts of greenhouse gas emissions. According to the passage, what is the reason for the rise of global temperatures?
The burning of fossil fuels. The rise of sea level. Extreme weather disasters. The emissions of greenhouse gases.