Broadcaster David Attenborough is urging world leaders to "act now" to do more to tackle climate change.

He was speaking at the annual UN Climate Change Conference (COP24) in Katowice, Poland.

It is being attended by some 40 heads of state and government.

In a world-first, the UN has launched the 'People's Seat' initiative.

This is a new way for people to express their views through social media and digital technology.

The conference goal is to finalise the implementation guidelines for the Paris Climate Change Agreement.

These will provide clarity on how to implement the agreement fairly and transparently.

Specifically, they will strengthen international cooperation by ensuring national contributions to the global effort are transparent, responsibility is shared fairly and progress on reducing emissions and building resilience can be accurately measured.

Six months after the 2015 Paris Summit, the negotiations on the implementation guidelines were launched and COP24 was set as the deadline.

While governments are committed to finalising the guidelines, the UN said a great deal of work still remains to be completed.

Addressing the gathering, Mr Attenborough said: "The world's people have spoken, their message is clear: time is running out.

"They want you - the decision-makers - to act now.

"They're behind you, along with civil society represented here today - supporting you in making tough decisions, but also willing to make sacrifices in their daily lives.

"To help make change happen, the United Nations is launching the Act Now bot - helping people to discover simple everyday actions that they can take, because they recognise that they too must play their part.

"The people have spoken - leaders of the world, you must lead: the continuation of our civilizations and the natural world upon which we depend is in your hands".

"We need to do much more"

The ActNow.bot is a fully interactive and responsive chat bot on the UN's Facebook page that suggests everyday actions that can be taken to preserve the environment, which can be shared with social media followers.

Patricia Espinosa is the UN's Climate Chief: "This year is likely to be one of the four hottest years on record.

"Greenhouses gas concentrations in the atmosphere are at record levels and emissions continue to rise. Climate change impacts have never been worse.

"This reality is telling us that we need to do much more - COP24 needs to make that happen".

Ms Espinosa noted that countries have strong backing for rapid climate action, given that public awareness and demand for solutions have increased.

"We simply cannot tell millions of people around the globe who are already suffering from the effects of climate change that we did not deliver".