Global COP26 climate negotiations are the "last, best hope" to keep the goal of limiting global warming to 1.5C alive, said summit president Alok Sharma as he opened the meeting on Sunday.
The Glasgow gathering, which runs to November 12, comes as an accelerating onslaught of extreme weather events across the world underscores the devastating impacts of climate change from 150 years of burning fossil fuels.
"We know that our shared planet is changing for the worse," Sharma said at the opening ceremony, as protesters gathered in the Scottish city to pile pressure on governments.
Experts warn that only transformative action in the next 10 years will help stave off far more cataclysmic impacts.
And the warming of the planet did not pause for the Covid-19 pandemic, which caused the UN meeting to be delayed by a year.
The last year alone has seen a once-in-a-thousand-years heatwave and scorching wildfires in North America, extreme rainfall and flooding in Asia, Africa, the US and Europe and severe drought in Madagascar, which Sharma said has been referred to as the "first climate-induced famine".
In a stark reminder of what is at stake, the World Meteorological Organization said Sunday the years from 2015 to 2021 were on track to be the seven hottest on record.
- 'Precious planet' -
COP26 inherits its central goal from the landmark 2015 Paris Agreement, which saw countries agree to cap global warming at "well below" 2C above pre-industrial levels, and 1.5C if possible.
That deal left many crucial details to be worked out, while emissions reductions remain woefully insufficient to avert global warming.
In August a bombshell "code red" report from the world's top climate science body warned that Earth's average temperature will hit the 1.5C threshold around 2030, a decade earlier than projected only three years ago.
And last week a UN report said even the latest, most ambitious carbon-cutting commitments would still lead to "catastrophic" warming of 2.7C.
COP26 now marks the "last, best hope to keep 1.5C in reach", Sharma said.
"If we act now and we act together we can protect our precious planet," he said.
Activists have mobilised in Glasgow to urge the delegates on, with Extinction Rebellion campaigners kicking off the proceedings on Saturday in a march of protesters in white face paint and flamboyant robes.
Greta Thunberg also arrived in the Scottish city late Saturday on a train that was mobbed by waiting journalists.
But others hoping to arrive in eco-friendly style were thwarted by severe rail delays.
- 'Investing in extinction' -
Much of the world's hopes for wrestling down emissions rest on the G20 richer nations -- whose leaders met in Rome at the weekend and whose economies account for about 80 percent of carbon pollution.
They committed to the key goal of limiting global warming to 1.5C and pledged to bring a halt to international funding for coal plants without emissions capture facilities.
They also pledged to reach a target of net zero carbon emissions "by or around mid-century", falling short of setting a clear 2050 date, as campaigners and summit host Italy were hoping for.
The world's focus on decarbonisation has sharpened in the face of increasingly dire warnings from scientists, central banks and security services about the threat posed by climate change, as well as global youth protests.
But governments under pressure to reboot their Covid-lashed economies continue to subsidise fossil fuels, even as they tout renewables.
UN climate chief Patricia Espinosa told the Glasgow opening ceremony that nations must turn away from business as usual or accept that "we are investing in our own extinction".
More than 120 heads of state and government will make the trip to Glasgow for the UN meeting, including US President Joe Biden, France's Emmanuel Macron, India's Narendra Modi and Australia's Scott Morrison.
But President Xi Jinping of China, the world's largest emitter, has not left his country during the pandemic and will not be travelling to Glasgow.
Vladimir Putin of Russia, another major polluter, will also be a no-show.
Sharma said more than 21,000 representatives from governments were registered, as well as nearly 14,000 observers and 4,000 media representatives.
With poorer nations least responsible for greenhouse gas emissions hit hardest by its impacts, inequality overshadows the COP26 negotiations.
The failure of rich countries to cough up $100 billion a year starting in 2020 to help developing nations lower emissions and adapt -- a pledge first made in 2009 -- will complicate the already fraught talks.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
