These are the human stories behind the UN's landmark science report, ITV News Deputy Political Editor Anushka Asthana reports
As wildfires blaze across southern Europe and parts of the US, just weeks after dramatic flooding in China and northern Europe left dozens dead, the world's largest ever report into climate change has set the stark reality of the state of the planet.
The assessment from the UN’s Intergovernmental Panel on Climate Change (IPCC) paints a bleak picture of the "unequivocal" impact human activity was having on the planet.
Without immediate, rapid and large-scale cuts to greenhouse gas pollution, limiting warming to 1.5C - the target set by countries in the Paris climate treaty - will be beyond reach, scientists say.
The report's key points:
Human-caused climate change has pushed up global temperatures by 1.1C and is driving weather and climate extremes in every region across the world.
There are already more frequent and intense heatwaves and heavy rainstorms in many places, including northern Europe, as well as droughts and cyclones.
Humans are also very likely the main driver in glacier melt, declines in Arctic sea ice, and rising sea levels.
Sea level rises are speeding up, with the oceans rising by 3.7mm (0.15 inches) a year in recent years, and are set to continue to rise this century whether emissions remain high or fall dramatically.
Changes to oceans, sea levels and melting permafrost and glaciers are irreversible for decades, centuries or even millennia as a result of past and future warming.
Cities are at particular risk as the climate warms, experiencing hotter temperatures in heatwaves and flash flooding from heavy rain.
Unlikely events such ice sheet collapses, abrupt changes to ocean circulation – which drives weather patterns – and much higher warming cannot be ruled out.
The paper drew on more than 14,000 scientific papers and has found it is “unequivocal” that human activity is warming the world.
Rapid and widespread changes to the land, atmosphere and oceans have occurred – from temperature increases to sea level rises – that are unprecedented for many centuries or even many thousands of years.
One of the report’s lead authors, Dr Tamsin Edwards from King’s College London, said: “Unless there are immediate, rapid and large-scale reductions in greenhouse gas emissions, the 1.5C target will be beyond reach.”
UN secretary-general Antonio Guterres described the report as a “code red for humanity”.
Speaking at an IPCC press conference on Monday, Inger Andersen, executive director of the UN Environment Programme, warned “it is time to get serious” and that “no-one is safe” during the climate crisis.
There are a lot of politics that will make it difficult for Boris Johnson to tackle the climate crisis, including worries that the poorest people will bear the brunt of the cost, Anushka Asthana says
The report released on Monday is the first part of the sixth global assessment of climate science to be undertaken since the IPCC was formed in 1988.
It looks at the physical science of climate change, with further parts of the review covering impacts and adapting to climate change, and solutions to the crisis, will be published in 2022.
The report comes as global temperatures have climbed to 1.2C above pre-industrial levels and increasingly extreme weather – from record heatwaves and wildfires to downpours and devastating flooding – hits countries around the world.
Despite the growing spectre of climate change, governments are not taking enough action to tackle the greenhouse gas emissions from human activity such as burning fossil fuels for heating, transport and power supplies to curb rising temperatures. UN climate chief Patricia Espinosa has warned that many countries have not brought forward new action plans for cutting their emissions – a key part of what they need to do before the Cop26 climate summit – and those that have are not doing enough.
Homes contribute around 15% of the UK’s carbon emissions and cleaning up fossil fuel heating systems, mostly gas boilers, is needed to meet legal targets to cut climate pollution to zero overall.
ITV News flew along a river route in Belgium to assess the damage wreaked by heavy floods last month. Across Europe at least 190 people died
The Climate Change Committee has advised that sales of gas boilers for homes should largely be phased out by 2033 and replaced by air source heat pumps, or be appliances that can be converted to a clean fuel supply, such as hydrogen instead of natural gas.
Responding to the report, Prime Minister Boris Johnson said: "We know what must be done... consign coal to history and shift to clean energy sources, protect nature and provide climate finance for countries on the frontline".
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Business Secretary Kwasi Kwarteng insisted the UK's targets were "robust".
"I think the job we have is to try and bring other people across the world to the net zero agenda and I think that's beginning to happen," he told ITV News. "We need a much stronger response from the international community. I think our targets, if we can stick to them, can really help deliver, help the planet, and avoid the catastrophe that's described."
Labour leader Keir Starmer the report was "the starkest reminder yet that the climate crisis is here right now and is the biggest long term threat we face".
“The biggest threat we now face is not climate denial but climate delay. Those who, like our Prime Minister, acknowledge there is a problem, but simply don't have the scale of ambition required to match the moment. Our communities and planet can no longer afford the inaction of this government, who are failing to treat the crisis with the seriousness it deserves."
"It should be a wake-up call" - Business Secretary Kwasi Kwarteng says the UK targets are "fairly robust".
The IPCC reports are an assessment of all the available science on climate change.
The report goes well beyond the previous IPCC assessment of 2013 when evidence of human-driven climate change was inconclusive. The global surface temperatures have increased by around 0.2 in the eight years since the last report.
This latest study involved 234 authors from around the world, who have received tens of thousands of comments on earlier drafts from scientists and governments.
Most importantly, the 41-page summary of the report has been subject to a line-by-line approval process involving scientists and representatives of the 195 governments before it is published – which has taken place online over the last two weeks.
That means governments have signed off on the findings – and pressure will be on them to take more action at global climate talks known as Cop26 which are being held in Glasgow in November.
A huge wildfire is burning in California, footage from the town of Greenville shows the devastation it is wreaking
A special report from the IPCC in 2018 warned that overshooting the 1.5C limit would mean more extreme weather, greater sea-level rises, and damage to crops, wildlife and health.
But the report, which assesses the potential impact of a range of five future scenarios from very low emissions to very high pollution, says temperature rises have a good chance of remaining below 1.5C in the long term if carbon emissions are cut to net zero by 2050.
Efforts to take more carbon dioxide out of the air than is put into the atmosphere, along with deep cuts to other greenhouse gases would also reduce the likelihood of temperatures rising above the threshold.
What are the key findings from the UN climate change report?
Cutting methane – produced by oil and gas drilling and agriculture, particularly livestock farming – could help curb rising temperatures, as well as improving air quality, the report said.
Over the weekend, Cop26 President Alok Sharma laid bear the enormous threat failing to curb emissions poses humanity.
In an interview with the Guardian, he warned world was getting “dangerously close” to running out of time to cut greenhouse gas, adding: “I don’t think we’re out of time but I think we’re getting dangerously close to when we might be out of time.”
Mr Sharma said: “Every fraction of a degree rise makes a difference and that’s why countries have to act now.”