Scientists have warned for decades that we were changing the climate in a way that would have devastating impacts on the planet and our lives. A landmark report on Monday showed that's already happening, and faster than we expected.
The findings, by the UN Intergovernmental Panel on Climate Change (IPCC), serve as a stern wake-up call for politicians, business leaders and policy makers, who in just 12 weeks will meet for the COP26 climate talks in Glasgow to address the biggest existential challenge in human history.
For decades, global policy has lagged behind the science, but leaders and big business are now being forced to play catch-up as their constituents and clients battle heat waves, wildfires and floods that are proving costly and deadly.
"You've got the politicians being squeezed by the science, which is confirming a sense of alarm and fear, you've got the science now in the public mind," said Tom Burke, co-founder of E3G, a European climate think tank.
"You've got capital markets saying this is beginning to really threaten the future value of our investments. So you've got enormous pressure building up on the politicians."
Amid the growing pressure, climate-minded policymakers are likely to face hurdles in making a success of November's COP26 conference, which is often measured by how far the most conservative leaders are willing to go. Recent multilateral meetings on climate between far fewer nations have ended with disappointing results, sometimes even in division.
Keeping 1.5 alive
Alok Sharma — president of COP26 — has said he wants the conference to reach agreement on a number of key targets, including putting an end date on the use of coal, a commitment to make all new car sales zero emissions within the next 14 to 19 years, stopping deforestation by the end of the decade and greater reductions of methane emissions.
But his main message is to "keep 1.5 alive".
Under the 2015 Paris Agreement, more than 190 countries signed on to limiting the increase in global temperatures to well below 2 degrees, but preferably 1.5 degrees, beyond which scientists say the world will experience more intense and frequent climate extremes.
But the G7 leaders' meeting in June and a G20 ministers' meeting last month left some on the global stage disappointed and unsure of what could be accomplished in November.
The G20 communiqué was delivered more than a day later than expected, as some countries opposed language on the issues of when to phase out coal and around the commitment to 1.5 degrees, according to Roberto Cingolani, Italy's ecological transition minister, who chaired the meeting.
Cingolani told reporters after the conference India and China were holding out on the issue of coal.
A source familiar with the talks at the time told CNN that the significant resistance was coming from fossil-fuel-producing countries, including some developing economies.
At a press conference on Monday, Mr Sharma denied that the 1.5-degree threshold was still divisive, and pointed to the communiqué G20 ministers ultimately agreed to, in which counties said they would "continue efforts" to limit it to 1.5 above pre-industrial levels.
"Based on all the conversations that I've had, I can tell you that there is a clear desire amongst governments to keep that 1.5 degrees within reach," Mr Sharma said.
Yet China's top climate negotiator Xie Zhenhua last week accused some countries of trying to shift the goal posts from 2 degrees, which countries agreed to in the Paris Accord, to 1.5 degrees.
"Some countries are pushing to rewrite the Paris Agreement," Mr Xie said, according to the AFP news agency.
"That is, they want to strive to change the target of control for the rise of temperature from two degrees Celsius to 1.5 degrees Celsius."
He added, "We have to understand the different situations in different countries, and strive to reach a consensus."
And while the G20 ministers eventually agreed to language around 1.5 degrees, some did so begrudgingly. India published its own statement alongside the communiqué defending developing nations' need to grow, urging richer countries to bring their emissions down faster.
Consigning coal to history
The G7 and G20 often try to show leadership in global policy areas — together, they represent 80 per cent of the world's emissions and about 85 per cent of the global economy. But the G20 meeting also failed to reach a concrete agreement on coal phaseout and the scrapping of fossil fuel subsidies.
Only 13 members of the G20 had committed to net zero, Mr Sharma pointed out Monday, and only eight had submitted new pledges that go beyond their previous ones. All signatories to the Paris Agreement were supposed to submit a second, more ambitious pledge by July this year.
Mr Sharma said the failure to reach an agreement on coal was "disappointing" and admitted securing one ahead of the COP26 conference would be tricky. He wants the world's richest countries to scrap coal by 2030 and the rest of the world by 2040.
Coal will be on the docket again at the next G20, which comes just before the COP26 summit.
$136 billion a year for the developing world
Another sticking point for developing nations is that they haven't received the money they were promised to adapt to climate change.
The developed world in 2009 agreed to transfer US$100 billion ($136 billion) every year to the developing world by 2020. That commitment was reaffirmed in the 2015 Paris Agreement but the goal was never met. Old divisions and distrust have resurfaced as a result.
A net zero economy powered on renewable energy involves overhauling infrastructure, employing new technologies, transitioning to electric vehicles and rethinking jobs and entire industries. Developing nations argue that many of the world's richest countries became wealthy because they were free to exploit the very fossil fuels they now want the rest of the world to phase out.
Withholding promised funds could mean that some countries are less likely to budge on scrapping coal and committing to 1.5 degrees.
What's at stake?
Already at 1.1 degrees above pre-industrial levels, the world is heading for average global temperatures of 1.5 degrees faster than scientists thought, the IPCC report said.
That threshold will likely be crossed in the mid-2030s, even if greenhouse gas is reduced sharply starting today.
The good news is we can keep it to 1.5 and avoid hitting 2 degrees, after which the impacts of climate change will become even more severe, according to the report.
"The key thing to focus on is that every degree of warming, that every tenth of a degree of warming, matters," Tamsin Edwards, a climate scientist at King's College London and one of the authors of the new IPCC report, told CNN.
"It's getting harder and harder every year to limit warming to 1.5 degrees because it means we have to cut emissions faster to get to net zero.
"The reductions in emissions have to be immediate, rapid and large scale."
If by the 2050s the world achieves net zero — where the net addition and removal of greenhouse gas is zero — it can contain temperature rises to 1.5 degrees.
The other good news is that the science shows that climate systems would respond well to carbon removal. Planting more trees, expanding carbon sinks and possibly using technology that is still being developed will limit the warming and its catastrophic consequences.
But so much has already been lost. Many of the effects of climate change are now "baked in" and impossible to reverse in the short term, like ice sheet and glacier melt that will cause sea level rises.
The question now is whether leaders will meet the moment and prevent the level of warming that will lead to catastrophe. It's also a question of whether politicians will learn from mistakes of the past.
"You've been telling us for over three decades of the dangers of allowing the planet to warm," UN Environment Program Executive Director Inger Andersen said to scientists on Monday, after the IPCC report launched.
"The world listened, but it didn't hear. The world listened, but it didn't act strongly enough.
"As a result, climate change is a problem that is here, now. Nobody's safe, and it's getting worse faster."