"Unless we act dramatically and quickly, science tells us our climate and our way of life are literally in jeopardy. Denial of the science is malpractice," warned U.S. Secretary of State John Kerry on Monday.
His urgent call to action came after the United Nations released it's most sobering account on the state of our climate yet. The second part of a trilogy on the causes, effects and solutions, it's the UN's first assessment on the impacts of global warming in seven years.
And, in a sharp departure from its last report, the Nobel Peace prize winning body said it's no longer some distant hypothetical threat: It's happening all around us, right now.
"Nobody on this planet is going to be untouched" warned Rajendra Pachauri, the head of the group's Intergovernmental Panel on Climate Change.
"Things are worse than we had predicted. We are going to see more and more impacts, faster and sooner than we had anticipated," says report co-author Saleemul Huq from the Independent University in Bangladesh.
That brutal assessment comes six months after the UN warned that our planet is warming much faster than expected: temperatures may now rise by two degrees Celsius within the next thirty years, before hitting the 4C mark by the end of this century.
According to one of the main authors of the report, the contrast between these two temperatures "is the difference between driving on an icy road at 30 mph versus 90 mph. It's risky at 30, but deadly at 90," says Michael Oppenheimer from Princeton University.
Although two degrees Celsius is widely cited as the upper safe limit of warming, according to the World Bank, such a temperature rise will "fundamentally" change the planet.
It will not only lead to more intense heatwaves, raging wildfires, devastating droughts and super storms like Haiyan and Sandy, it will also magnify already existing issues such as hunger, sickness, poverty, and violence.
"We're facing the specter of reduced yields in some of the key crops that feed humanity," says Rajendra Pachauri. Output for all staple foods like wheat, rice and corn are expected to fall by 2 percent every decade, with some projections showing losses of more than 25 percent.
By 2050, the cost of food could rise between 3 percent to 84 percent. Yet at the same time, the world will have 2 billion more mouths to feed.
And, as food becomes less available and more expensive, more people will battle against hunger, creating new poverty pockets even in wealthier nations, sharpening the inequality divide between the rich and the poor.
According to some analysts, it was higher food prices that unleashed the Arab spring. The cost of meat, dairy and wheat were all at record highs a month before the collapse of both the Tunisian and Egyptian regimes.
Although no one will be immune for the inevitable price hikes and riots that will follow, it will be the poor who will be hit the hardest. And, as they had little hand in creating the problem, "that is fundamentally unfair," says the head of the World Bank, Jim Yong Kim.
He warns that if global temperatures continue to rise, the World Bank's goal of eradicating poverty by 2030 will slip out of reach: "Decades of achievement in development will be wiped out if we let the planet warm by two degrees celsius."
And, while poorer nations will suffer more, wealthy countries won't escape unscathed as the recent UK floods, and current drought in California illustrate:
"These are multibillion dollar events that the rich are going to have to pay for, and there's a limit to what they can pay," says Dr Huq.
He warns that "the really scary impacts are when things start getting together globally. If you have a crisis in two or three places around the world, suddenly it's not a local crisis. It is a global crisis, and the repercussions of things going bad in several different places are very severe."
Moreover, at a certain point of warming, sudden irreversible and dramatic tipping points could occur. "Disturbingly, scientists do not know how much warming is required to trigger such changes" noted America's leading scientific society the AAAS in its latest report last month:
"The financial meltdown of 2008 was a good example of this kind of risk. Few experts recognized the risk indicators that led to enormous and rapid economic consequences."
"I can't think of a better word for what it means to society than 'risk,'" says Virginia Burkett, one of the study's main authors from the U.S. Geological Survey. The summary mentions the word over 230 times: that's 6 times higher than seven years ago.
The problems have now escalated to such a level that the report has added a new band of color to its risk spectrum: It's dark purple.
Maarten van Aalst, report co-author, and a top official at the International Federation of Red Cross describes it is a horrible risk: "The horrible is something quite likely, and we won't be able to do anything about it."
Although some critics have denounced the report as being too alarmist, the UN's conclusions tend be very conservative as they are always drawn from a consensus process which has to be unanimously approved.
Based on over 12,000 peer reviewed studies, the 2,600 page report by over 300 scientists "is the most solid evidence you can get in any scientific discipline. There is so much information, so much evidence, that we can no longer plead ignorance," says Michel Jarraud from the World Meteorological Organization.
Rajendra Pachauri, who has headed the IPCC for 12 years, hopes that this report "will jolt people into action."
Aimed at world leaders ahead of all important climate talks next year, the 49 page summary, has been unanimously approved by 100 governments. It comes six months before heads of state gather in New York for a high level UN summit aimed at forging a global deal to rein in carbon emissions by 2020.
Earlier this year, the world's largest emitters, the U.S. and China vowed to lead the charge against climate change. Analysts now hope that commitment by the world's two largest powerhouses will pave the way towards a strong accord next year.
Although many nations have already taken several steps to rein in their emissions at home, the pace and scale of change is just not fast enough.
The world can still avert the worst effects of man made climate change, but "we have have to act now. We have a closing window of opportunity," says study co-author Patricia Romero-Lankao from the National Center for Atmospheric Research.
Later this month, the UN will publish the final installment of its blockbuster trilogy: the solutions to global warming. The panel along with former US vice president Al Gore, won the Nobel Peace Prize in 2007 for its efforts to highlight the risks of climate change.