It's a legally binding agreement to fight climate change, where countries committed to keeping global warming well below 2 degrees Celsius above pre-industrial levels and, if possible, below 1.5 degrees.
Nor are any of the world's largest emitters represented at the highest level in Poland.
The planet has already warmed 1 degree Celsius since pre-industry times due to human activity and we've already begun to see the impact of the rise in global temperatures.
Officials from almost 200 countries now have two weeks to finalize how those goals work in practice, even as science suggests the pace of climate change is rapidly outstripping mankind's response. One of the key disputes is finance. "Governments and investors need to bet on the green economy, not the gray".
Decisions on crunch issues, which may include financial aid for poor countries, are expected to be left to ministers when they gather at the domed conference venue in the southern Polish city of Katowice next week.
The British environmental website Carbon Brief attributed Attenborough's change in perspective to a lecture by American scientist Ralph Cicerone in 2004, in which Cicerone showed graphs of world temperature, global population and the make-up of the atmosphere.
"Even as we witness devastating climate impacts causing havoc across the world, we are still not doing enough, nor moving fast enough, to prevent irreversible and catastrophic climate disruption", Guterres said.
Natural historian Sir David Attenborough listens to speeches during the opening of COP24 UN Climate Change Conference 2018 in Katowice, Poland.More news: Trump leads tributes to 'inspirational' George Bush
"As a effect, access to water, food, the conditions for stability, peace and prosperity are more than ever under threat; and if the emissions gap is not closed by 2030, it is extremely unlikely that the 2°C temperature goal, let alone the 1.5°C, can still be reached", they warned.
Guterres said governments should embrace the opportunities rather than cling to fossil fuels such as coal, a dig at hosts Poland.
"This is the challenge on which this generation's leaders will be judged", he said.
Just last week, the UN's environment programme said the voluntary national contributions agreed in Paris would have to triple if the world was to cap global warming below 2C.
The veteran naturalist and TV presenter, whose most recent series, Blue Planet II, focused on the destruction of the oceans by pollution, called on the world's leaders to actually lead in the battle against man-made climate change.
Nations more immediately threatened by climate change, including Fiji, are urging for nations to act now.
"We are approaching risky climate thresholds, species are disappearing at an unseen rate, lands are degrading at an accelerated pace and global carbon dioxide emissions increased in 2017 after a three-year period of stabilization".
Representatives of some of the most powerful countries and biggest polluters were conspicuous by their absence, and the United States is quitting the UN climate process.