PM Demands New Global Temperature Target

David Cameron has called for world leaders to agree a deal on cutting greenhouse gas emissions and limiting the global temperature rise this century to 2C.

At a UN summit in Paris, the Prime Minister said delegates owed it to younger generations to make the figure legally binding in an attempt to tackle climate change.

The threshold is seen as the safe limit, beyond which the climate becomes dangerously unstable. Before the conference, countries made pledges on greenhouse gas cuts that would cap warming at 2.7C.

Mr Cameron pointed out sea levels were rising, crops were failing, deserts were expanding and 97% of scientists said climate change was manmade, urgent and must be addressed.

And he said 75 countries, including the UK, already had legally binding climate change legislation and they were "thriving, not suffering".

Mr Cameron wants a review every five years to see how the world is doing, and to help the poorest countries with finance and also make sure they get the technology that the richest nations have.

He is among more than 150 leaders attending the first day of the global summit.

Negotiators will spend the next fortnight trying to thrash out a deal to prevent temperatures rising by more than 2C above pre-industrial levels.

The Prime Minister said: "Instead of making excuses tomorrow to our children and grandchildren we should be taking action against climate change today.

"What we are looking at is not difficult - it is doable and we should come together and do it."

In advance of the summit, known as COP21, 183 countries submitted individual commitments, large or small, to slow global warming.

The EU has pledged to reduce greenhouse gases by at least 40% by 2030, while the world's biggest emitter, China, has vowed that its emissions will peak by 2030.

These "differentiated responsibilities" allow the world to share an overall goal of limiting emissions by 40-70% by 2050, according to the UN.

The EU wants any deal to be legally enforceable, but that is being resisted by the US.

And poorer countries that are most vulnerable to climate change want richer nations to pay into a fund to help them adapt to a warmer world.

President Barack Obama urged world leaders to "act now" to secure a future for humanity.

He said the US, as the world's number two greenhouse gas emitter, "recognises our role in creating this problem" and "we embrace our responsibility to do something about it".

Prince Charles used his keynote speech to warn humanity faces many threats "but none is greater than climate change".