They aim to establish rules, figure out financing and build ways to verify that nations are meeting their commitments.
"At the upcoming summit, we expect G20 countries to demonstrate their commitment to the Paris Agreement and to taking the necessary action to limit warming to 1.5°C, including by moving forward with the Hamburg Climate and Energy Action Plan from previous year". "If we don't take action the collapse of our civilisations and the extinction of much of our world is on the horizon".
"The world's people have spoken", Attenborough summed up.
The Arc de Triomphe is illuminated in green with the words "Paris Agreement is Done", to celebrate the Paris U.N. COP21 Climate Change agreement in Paris, France, Nov. 4, 2016. "So, we need a huge increase in ambition".
"Right now, we are facing a man-made disaster of global scale", Attenborough began.
Africans expect "real action" on climate change, said delegates from the African group, as an global climate conference began in the southern Polish city of Katowice on Monday.
Prior to COP24, there were many worldwide efforts to bring about a successful outcome, including the Bonn Climate Change Conference in Germany in April, followed by the Bangkok Climate Change Conference in Thailand in September.
"We have a collective responsibility to invest in averting global climate chaos", he said. "Leaders of the world, you must lead".
Guterres called for a "huge increase in ambitions" during the two weeks of negotiations in Poland, adding "we can not afford to fail in Katowice". "Climate action offers a compelling path to transform our world for the better".
The World Bank on Monday pledged to commit as much as Dollars 200 billion from 2021 to 2025 towards fighting the threat of climate change during the 24th Conference of the Parties (COP 24) summit here.
Marches aimed at showing support for ending the use of coal-fired power plants and other efforts to limit climate change drew thousands of people over the weekend in Brussels, Berlin and Cologne.
"We are here to enable the world to act together on climate change", said Poland's environmental envoy, Michal Kurtyka, who is presiding over the United Nations meeting, known as COP24.
UN Secretary-General António Guterres has asked decision-makers to focus on four key things - a solid plan, stepping up climate action, more funding and smart investment in the future of the planet.
Heated debates are expected to dominate the two-week climate talks, considered the most important negotiations after the successful COP21 in Paris.
At the same time, U.S. President Donald Trump has regularly denied the existence of climate change and its links to humanity.
Patti Lynn, executive director of the Corporate Accountability campaign group, called for nations to agree to the global greenhouse gas draw-down upon which the fate of the Paris agreement now rests.
ASSOCIATED PRESS Prime Minister of Fiji, Frank Bainimarama, addresses representatives of nearly 200 nations during a ceremonial opening of the key U.N. climate conference.
At the framework of a Talanoa Dialogue, the six panelists, including Bangladesh Environmental Lawyers Association (BELA) Chief Executive Chief Executive Syeda Rizwana Hasan, Dr Nahid Rezwana of Dhaka University, Dr Sultan Ahmed of Ministry of Environment and Forests, as well as almost 40 invitees were given a voice to share their stories, ambitions and engagements regarding climate change.