Poland's deputy environment minister, Michal Kurtyka, who is chairing the conference, urged envoys from nearly 200 nations to use the time between Sunday and December 14 to make progress on fleshing out the 2015 Paris agreement. The 20 warmest years on record have all occurred within the last 22 years, and the top four in the past four years, The Guardian noted.
"The upcoming climate talks are the most important round of negotiations since the Paris Agreement was reached three years ago", Lou Leonard, the World Wildlife Fund's senior vice president for climate change and energy, told CNBC of the talks that gather thousands of world leaders, activists, and policymakers to flesh out a framework for the Paris Climate Agreement. Beyond this, humanity will face far higher risk of drought, floods, extreme heat and poverty.
Such a move, which experts say is the only way to achieve the 1.5-degree goal, would require a radical overhaul of the global economy.
Delegates were played a montage of messages collected from people around the world.
Of the 10 countries in the world considered most threatened by climate change, seven are in Africa - Central African Republic, Chad, Eritrea, Ethiopia, Nigeria, Sierra Leone and South Sudan.
Attempting to raise awareness about how bad the situation is, the United Nations invited renowned David Attenborough to take the stage.
"We are trying to save the world from annihilation, but we must do this in a way that those who live with us today in the world have the best possible living conditions", Polish President Andrzej Duda said. 2018 is the year the countries committed to putting a plan in place for carrying out the agreement, so time is running out.
Separately, negotiators will discuss ramping up countries' national emissions targets after 2020, and financial support for poor nations that are struggling to adapt to climate change.
Guterres called on representatives to cement funding agreements, allowing the global community to take firm steps towards green solutions, suggesting the world was "nowhere near where it needs to be" on moving to a low-carbon economy.
"We need serious solutions from serious leaders, not unsafe schemes and political tricks aimed to keep big polluters polluting", she said.
Attenborough, who has produced and narrated numerous nature documentaries, is a strong advocate for fighting climate change - but that wasn't always the case.
"Developed nations led by the United States will want to ignore their historic responsibilities and will say the world has changed", said Meena Ramam, from the Third World Network advocacy group. "Governments and investors need to bet on the green economy, not the gray".
The President had on Sunday in Krakow, Poland, during an interactive session with the Nigerian community in the country, denied the rumour that he is a clone.
He also said that "climate action is not just the right thing to do, it makes social and economic sense", pointing to how action to cut emissions will curb air pollution deaths and generate millions of jobs and trillions of dollars.
The remark was directed at host Poland, which relies on coal for 80 per cent of its energy. Polish coal company JSW is one of the main sponsors of the talks, which also does not bode well for COP24.