Kyoto Protocol?

When more than 180 nations signed the Kyoto Protocol in 1997, the idea was straightforward: Take a first step toward saving the earth from irreparable damage due to climate change. The protocol set forth what the drafters considered to be realistic emissions-reduction goals for developed nations, essentially a decrease in pollution levels that would start to mitigate climate change.

This climate change refers to an increase in average global temperatures attributed at least partly to humans and our greenhouse-gas emissions, mostly the burning of fossil fuels in automobiles, factories and power plants. Carbon dioxide, methane and nitrous oxide are just a few greenhouse gases. They cause heat to be trapped in the Earth's atmosphere much the way a glass ceiling traps­ heat inside a greenhouse. The result is rising temperatures that could alter weather systems and ocean levels around the globe.

With many areas of the world facing record winter lows in 2009, and gas distribution problems in Eastern Europe leaving some of those people without heat, an increase in temperature may not seem like such a bad thing. But the side effects of that temperature increase could be disastrous, including severe flooding, more treacherous storms that happen more often and changes in ocean temperature that affect crucial sea life.

The intent of the Kyoto Protocol was to curb greenhouse gas emissions and thereby hopefully avert this disaster. It aimed for a combined effort that would bring emissions down to 5 percent below what they were in 1990. Of the nearly 200 nations that signed, only the 37 "developed" nations took on emissions-reduction goals; developing nations were given a pass so that environmental concerns didn't interfere with their economic development. Instead, those nations were supposed to host projects that would further the emissions goals -- projects paid for by the developed countries.

Of the 37 developed nations, one never ratified it. Ratification makes a country legally bound to the commitment it made when it signed the document. That one country is the United States , the world's largest emitter of greenhouse gases. But many countries that did make commitments are failing to live up to them.

One of the major problems faced by Kyoto is one that affects all world agreements: Getting the entire world to work toward a single goal is a very difficult feat to achieve.

source : http://science.howstuffworks.com/kyoto-protocol-expire.htm