The November 30th-December 11th UN summit in Paris will be opened by world leaders, including US President Barack Obama, China's Xi Jinping and Narendra Modi of India.
With France still under heightened terror alert following January's attacks and a series of botched attempts in the months since then, security at the conference will be tight.
On Friday Bernard Cazeneuve, the country's interior minister, announced that border checks will be restored for the length of the summit.
"For a month we are going to set up checks on borders," Cazeneuve told French media.
The EU's Schengen border rules, which allow free movement of travel, give countries the right to restore checks temporarily during certain events such as a gathering of world leaders or sporting occasions like the next European Championships, which will take place in France.
The aim of COP 21 is to unite all the world's nations in a single agreement on tackling climate change, with the goal of capping warming at two degrees Celsius (3.6 degrees Fahrenheit) over pre-Industrial Revolution levels.
The agreement will be backed by a roster of national pledges for reducing greenhouse gas emissions blamed for global warming.