The comments came at the beginning of a two-week climate conference in Katowice, Poland, where emissaries from almost 200 nations are meeting to determine how the world can dramatically scale back greenhouse gas emissions to abide by the landmark Paris climate agreement and, by doing so, stave off the worst effects of climate change.
Guterres said climate change was already taking its toll.
British broadcaster and environmentalist David Attenborough on Monday (Dec 3) urged world leaders, meeting in Poland to agree ways to limit global warming, to get on and tackle "our greatest threat in thousands of years".
The aim of the two-week summit is to build on the landmark 2015 Paris climate accord which focused on strengthening the global response to the threat that climate change poses to the planet.
Guterres pleaded with countries to reduce their emissions from 2010 by 45 per cent by 2030 and to set a goal to release a net zero emissions by 2050, recalling consequences laid out in the 700-page report written by the Intergovernmental Panel on Climate Change (IPCC).
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 and a move away from using fossil fuels.
"In short, we need a complete transformation of our global energy economy, as well as how we manage land and forest resources", Mr Guterres said.
Attenborough, known worldwide for his uniquely passionate nature documentary narrations, was invited to the COP24 United Nations climate conference in the city of Katowice as a representative of the people of the world, many of who sent in messages that Attenborough reportedly used to inform his speech.
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The conservationist is serving in the "People's Seat" during the conference, a role in which he will present comments from members of the public affected by climate change to the dignitaries and officials present at the summit.
President Donald Trump has threatened to pull the US out of the Paris agreement because of what he says is the economic damage the treaty's provisions would cause. "I think conservationists have to be careful in saying things are catastrophic when, in fact, they are less than catastrophic", he told The Independent in 2006. "It's very sad, but if they don't do anything right now that is the truth".
Guterres said he hopes to have progress by then on efforts to mobilize $100 billion to help developing nations reduce their emissions and adapt to climate change.
He later told reporters realities of global climate changes were, "worse than expected, but the political will is relatively faded after Paris" and was not matching the current challenges. The only holdout was the United States, which announced under President Donald Trump that it is withdrawing from the climate pact.
The conference is called COP24 - which stands for Conference of Parties.
"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.
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.