The weather has been breaking new records, with this year expected to be the warmest on record. July, August and September have been the hottest months since modern records began.
A look at how 2015 stacks up against the six warmest years on record:
In Paris, nearly 200 nations will meet from Nov 30 to Dec 11 to try to agree on the final shape of a global pact to curb the pace of climate change.
Ultimately, the pact is about cutting greenhouse gas emissions, chiefly carbon dioxide (CO2) from burning fossil fuels in cars, power stations and industry. CO2 builds up in the atmosphere and oceans, trapping extra heat that is fuelling wilder weather.
Emissions from industry, power stations, and transport have risen quickly, particularly in developing nations.
The United Nations says global carbon dioxide emissions need to peak soon and then start to fall quickly to avoid the worst impacts of climate change.
A look at how much carbon dioxide is being emitted by these countries in 2003 and 2013: