The global climate talks that officially open on Monday in Paris are a massive undertaking both diplomatically and logistically, with some 40,000 visitors expected daily amid heightened security fears.  

The summit will operate like a temporary town over the coming two weeks -- providing work space, food and protection for its guests that include scores of world leaders.

Here are some of the key numbers:

150

The number of heads of state and government expected to attend opening ceremonies on Monday, with each leader due to make a speech of several minutes.   

195

The number of nations which are members of the United Nations Framework Convention on Climate Change (UNFCCC), which is organising the conference. Some 10,000 delegates, 14,000 representatives of civil society and at least 3,000 journalists are registered to attend.

18  

That's the tally in hectares, equivalent to 45 acres, for the area of the talks venue, located just north of Paris in Le Bourget. Most of the conference centre will be open only to negotiators and others with accreditation, though there will be sections for the general public and businesses.

21,000

The tonnage of greenhouse gas produced by the conference. That's equal to the annual carbon dioxide (CO2) emissions of 4,420 cars over the course of a year. The pollution will be compensated ("offset") by CO2-curbing projects in the southern hemisphere, the French government says.

412,000

The number of meals to be served over the scheduled duration of the November 30-December 11 talks. But UNFCCC conferences of the parties -- COPs -- are notorious for overrunning.

32

The number of negotiating rooms at the sprawling conference centre in Le Bourget. There are also two plenary halls with a total of 3,300 seats, as well as about 20 rooms for parallel events.   

2,800

The number of police and gendarmes who will be responsible for security at the conference. Some 8,000 additional law enforcement personnel are to be deployed at France's borders.  

At least 100 UN security personnel as well as 300 private security guards are to be patrolling the conference, which opens just weeks after France suffered its worst ever terror attack.  

70,000

The number of additional places that have been created on public transport in the Paris area during the conference. Special bus lines and a fleet of 200 electric cars will ferry conference delegates to and from central Paris.

170-186 million

That's the budget in euros, equal to $180-196 million, that France has set for the conference, with an additional 25 million euros in assistance -- primarily services and materials -- coming from about 50 French and foreign companies.

Organisers expect the event will bring in about 100 million euros to the greater Paris region mostly through participants' spending on lodging, food and shopping.