What is the Kyoto Protocol?
Signed in 1997 during a United Nations summit in Kyoto, Japan, the agreement says by 2012 developed nations should reduce their greenhouse gas emissions by 5.2 per cent below 1990 levels. The protocol has been approved by 141 nations.

Is the Kyoto Protocol legally binding?
The Kyoto Protocol came into force on Feb. 16, after 55 nations, accounting for 55 per cent of the carbon dioxide produced by the world's developed nations, had ratified the deal. The United States withdrew from the deal in 2001, saying it would cost the U.S. too much to meet its emission-reduction obligations and that the Kyoto Protocol didn't require developing nations, which also produce greenhouse gases, to make any effort to reduce their emissions.

Do all the nations which have signed on have to reduce their emissions by 5.2 per cent?
Only 39 nations, among the world's most developed, have said they'll do this by 2012. Each nation has its own specific goal. Russia wants to reach its 1990 level by 2012, while the European Union wants to trim its emissions by eight per cent.

Are they making progress?
Most nations are lagging behind and many have increased their production of greenhouse emissions in the last 15 years so the job of reducing them below 1990 levels will be even harder. Spain and Portugal are producing 40.5 per cent more emissions now than in 1990.

What exactly are these emissions, or greenhouse gases?
These are gases which trap heat in the atmosphere. The main greenhouse gas is carbon dioxide, which comes from burning fossil fuels such as gas, oil or coal, but the Kyoto Protocol also touches on other greenhouse gases, such as methane, which comes from fertilizers or decomposing vegetation, as well as three other industrial gases commonly used in refrigeration units.

Why do we want to reduce levels of greenhouse gases?
According to many models and in the opinion of many scientific experts, these gases contribute to the warming of the climate.

How are other nations going to meet their 2012 levels?
The European Union is placing emission quotas on factories and power plants. If they can't meet these quotas, they'll have buy the right to produce more emissions from others, or pay fines. The right to produce a ton of carbon dioxide is now priced at about 7.2 euros ($15).

Nations can also meet their targets under Kyoto by receiving credits for investing in clean renewable energy or tree planting efforts.

What's the next step after the Kyoto Protocol?
After the signatories meet their obligations, they're supposed to further reduce their emissions by an additional 30 per cent, starting in 2013. A U.N. conference, scheduled for next November in Montreal, will start looking at this question.