Read this on CNN news. 90% of the reasons shows that mankind are the cause of the Global warming. Thanks to our daily air-con/fridge consumption destroy the ozone layer. Increase of CO2 release by industry which produce us our daily needs, not enough forest to convert CO2 back to O2 became a main problem for the Mankind to live peacefully.

CNN reports :

Global warming isn't opinion. It's a scientific reality backed by tens of thousands of peer-reviewed conference papers, dissertations, reports, and journal articles. And the science tells us that human activity has made enormous impacts to our planet that affect our well-being and even our survival as a species.

	More carbon dioxide is now in the atmosphere than has been in the past 800,000 years.
	The massive ice sheets in the Arctic are melting at alarming rates.
	As temperatures rise, disease-carrying mosquitoes and rodents spread, infecting people in their wake.
	Super powerful hurricanes, fueled by warmer ocean temperatures are the "smoking gun" of global warming.
	The planet has ten years to get carbon dioxide emissions (mostly from energy production and the use of fossil fuels) under control to prevent the one degree Celsius temperature increase necessary to trigger non-linear feedback loops caused by wide-scale release of methane (20X worse per unit than carbon dioxide) that would irreversibly change the climate of the planet, increase temperatures further, and trigger a wide variety of climate catastrophes including a 20+ meter rise in sea levels that would make hundreds of millions of people homeless refugees, droughts in grain producing areas, and increase the frequency and impact of destructive weather events.
	Action must be prompt, otherwise CO2-producing infrastructure that may be built within a decade will make it impractical to keep further global warming under 1°C.
	The special interests seek to maintain short-term profits with little regard to either the long-term impact on the planet that will be inherited by our children and grandchildren or the long-term economic well-being of our country.
	The public, if well-informed, has the ability to override the influence of special interests, and the public has shown that they feel a stewardship toward the Earth and all of its inhabitants.
	We have already largely wasted one year. We have nine more years.
	The Earth's history suggests that with warming of 2-3°C the new equilibrium sea level will include not only most of the ice from Greenland and West Antarctica, but a portion of East Antarctica, raising sea level of the order of 25 meters (80 feet).
	We must stabilize carbon dioxide levels at or below 450 parts per million to prevent the worst-case scenarios that would result if we allow global temperatures to rise more than 2 degrees Celsius. In practical terms, this means that the United States needs to cut carbon dioxide emissions by 94% by 2030.

So.. what is the effect of just 1 degree increase in temperature? The effect is devastating.

http://www.cnn.com/2007/TECH/science/02/02/climate.change.report/index.html