Terrorist attacks in Paris are not expected to stop the United Nations from hosting a major climate conference in that city. Next week nearly 120 heads of state and government will gather in the City of Lights to discuss ways to cut harmful pollution.

President Barack Obama, China's Xi Jinping and Russia's Vladimir Putin are scheduled to attend. They will try to reach an agreement to fight changes in the Earth’s climate. The meeting is known as COP21. The U.N. says it wants an agreement among nations to limit the rise in world temperatures to 2 degrees Celsius.

Before the terrorist attacks, France hosted a pre-summit meeting. France's Laurent Fabius told journalists that “the task ahead is considerable.”

Governments are discussing how to lower harmful gas released from burning fossil fuels, like oil and gasoline. These have been blamed for climate change. Experts warned recently that a major glacier in Greenland is quickly melting and falling into the Atlantic Ocean. If the entire glacier in the northeast of Greenland melts and falls, global sea levels could rise by a half meter.