U.N. climate talks reached a milestone Saturday when more than 190 countries adopted the first accord asking all countries to join the fight against global warming.
Here are some of the key elements of the deal:
—LONG-TERM GOAL: The long-term objective of the agreement is to make sure global warming stays "well below" 2 degrees Celsius (3.6 degrees Fahrenheit) and to "pursue efforts" to limit the temperature rise to 1.5 degrees Celsius (2.7 degrees Fahrenheit). Temperatures have already increased by about 1 degree Celsius (1.8 degrees Fahrenheit) since pre-industrial times. To achieve that goal, governments pledged to stop the rise in heat-trapping greenhouse gas emissions "as soon as possible." By some point after 2050, the agreement says, man-made emissions should be reduced to a level that forests and oceans can absorb.
—EMISSIONS TARGETS: In order to reach the long-term goal, countries agreed to set national targets for reducing greenhouse gas emissions every five years. More than 180 countries have already submitted targets for the first cycle beginning in 2020. Only developed countries are expected to slash their emissions in absolute terms; developing nations are "encouraged" to do so as their capabilities evolve over time. Until then, they are expected only to rein in the growth of emissions as their economies develop.