The UN’s Intergovernmental Panel on Climate Change (IPCC) released its latest report on the earth’s climate Sunday, and it reaffirms what climate alarmists have been yammering for years. Chicken Little has nothing on these guys.

“Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system,” the report states, “increasing the likelihood of severe, pervasive and irreversible impacts.” The report notes that governments now face the question of whether they can act to slow global warming to a pace at which humans and ecosystems can adapt, or risk “abrupt and irreversible changes” to the planet.

The report is the final piece of work in five years of assessments by thousands of scientists, and it is meant to offer a framework of data for world leaders to work with when they meet in 2015 to debate an international climate treaty. There have been a number of these five-year assessments since the 1990s, but this latest one contains the direst of predictions.

The IPCC concludes with 95% certainty that global warming is a man-made phenomenon, and the warming trend seen on land and in the oceans since the 1950s is “unequivocal.” According to IPCC research, each of the last three decades have been successively warmer, with the period from 1983 to 2012 likely being the warmest 30-year period in the Northern Hemisphere in the last 1,400 years. This would be an alarming piece of news except for the fact that the report admits this 1,400-year assessment is merely theoretical.

There have been previous theories about the sources and dangers of global warming. Rational scientists – the ones conveniently labeled “deniers” by ecofascists – have frequently questioned the methods by which the IPCC and its associated scientists collect their data. There was the famous “hockey stick” debate of 2003, when statisticians proved that the data behind the theory of steeply rising global temperatures was fundamentally flawed. And let’s not forget Climategate, the 2009 scandal in which the University of East Anglia’s Climate Research Unit was caught fudging its climate data in an effort to prove the dire consequences of man-made global warming.

The IPCC remains undeterred in its mission, and inconvenient truths won’t get in its way. For instance, 18 years in which we have seen no warming accompanied by yet another record extent in Antarctic sea ice is considered temporary and due to “natural variability.” The IPCC report calls this trend merely a pause: “Trends based on short records are very sensitive to the beginning and end dates and do not in general reflect long-term climate trends.”

So an 18-year block within the time period from 1950 to 2014 is a short record without scientific meaning, but the IPCC bases its “settled science” on a 64-year block (1950-2014) within a 1,400-year period – that is admittedly theoretical – and we’re just supposed to accept that as fact.

The IPCC points out that it does not have the power to make policy, but it’s surely going to do everything it can to help shape whatever policy governments will make when they gather in Paris next year. The report claims a global temperature rise greater than 2°C would be catastrophic. If that threshold is crossed, the damage caused by global warming would be irreversible – even if all fossil-fuel use were to end tomorrow. By the way, that 2°C threshold was developed in 2009 and is relative to the 1861-1880 baseline for global temperature. There seems to be no explanation why this statistically short record is now gospel as opposed to any other 20-year span prior to the mass production of the automobile.

In any event, if this seemingly arbitrary 2°C threshold is to be maintained, carbon emissions need to be brought to near zero by 2100. “It’s not too late,” says Gary Yohe, a professor from Wesleyan University who contributed to the report. “But the longer you wait, the more expensive it gets.” It’s never too late for these folks.

Just how expensive will it be? The report is evasive: “These impact estimates are incomplete and depend on a large number of assumptions, many of which are disputable. … As a result, mitigation cost and climate damage estimates at any given temperature level cannot be compared to evaluate the costs and benefits of mitigation.” That’s a convenient way to avoid the hot seat for something that would drastically reduce global GDP over the next 85 years.

Ronald Bailey of Reason Magazine boils it down: “One way to think of this is that people today making an average global per capita income of just under $10,000 per year are being asked to sacrifice economic growth and development for people whose incomes will likely be over $61,000 per year in 2100.”

While the IPCC admits there are disputable elements and that it cannot determine just what the economic impact of its proposals would be, it argues we should unquestioningly accept its final conclusion.

The IPCC and its climate alarmist cohorts are asking the world to put the brakes on economic development based on information that is still very much up for debate. But never mind that, they say, the “Science™ is settled.”