So they've signed a historic climate deal in Paris, but what does it mean?
![COP21 Climate Conference COP21 Climate Conference](http://web.archive.org./web/20170306071553im_/http://www.abc.net.au/news/image/7024428-3x2-700x467.jpg)
- The agreement was approved by all 195 countries who attended the summit and will commence in 2020
- It aims to transform the world's economy from dirty fossil fuels to renewables
- Importantly, it aims to slow the pace of global warming to "well below 2 degrees Celsius, perhaps 1.5" below pre-industrial levels
- It provides billions more dollars to help poor nations transition to a greener economy
- By the second half of the century the emissions from human activity must be matched by the amount being captured by carbon-absorbing sinks such as forests or carbon storage technology
But the agreement does not mandate specific measures or targets. Instead, it creates a system for ensuring countries make good on voluntary domestic efforts to curb emissions.
Read more highlights from the deal here
So, what does it mean for Australia?
Australia's target of a 26 to 28 per cent reduction in greenhouse gas emissions below 2005 levels by 2030 has not changed.
But the Paris agreement will put pressure on the Government to do more.
Australia will have to review reduction targets every five years after the treaty comes into action in 2020 with each stocktake resulting in a more ambitious target.
Foreign Minister Julie Bishop said:
"No country would see this as the perfect outcome. Certainly it does not include everything that we envisaged. However, this agreement does give us a strategy to work over coming years and decades to build the strong and effective action the world needs."
Tiny island nations whose survival depends on the rest of the world taking action on climate change played an integral role in the summit. Marshall Islands foreign minister Tony de Brum summed up the last fortnight:
And just to recap, what is climate change, exactly?
Well, scientists have warned for decades that the increase in carbon dioxide in the atmosphere — largely from burning coal, oil and gas — would lead to more of the Sun's heat being trapped on Earth.
This year is shaping up to be the hottest year on record, with 2014 the previous record holder.