The State of the Climate in 2017: "Truly Uncharted Territory"

Global average temperature during the Holocene. Blue curve: Global temperature reconstruction from proxy data of Marcott et al, Science 2013. Recent instrumental measurements shown in red. Note that the instrument reading (red line) is four years out of date and therefore ends at a lower point than if it reflected today's reading. Graph: Klaus Bitterman. (Source; my annotation; click to enlarge)

by Gaius Publius

Bottom line first — We now have one more source saying that global warming is well above +1°C and headed higher at unanticipated rates. Key quote: We're in "truly uncharted territory." To jump to that news, click here.

Not long ago in these pages I took a look at the actual state of global warming as compared to "pre-Industrial global temperature" — the average global temperature prior to the warming caused by the Industrial Revolution — and discovered that the global warming "headline number" was too low, a fact that's causing a dangerous complacency.

The Industrial Revolution and the Watt Steam Engine

Some context: The Industrial Revolution can be said to have started with the invention of the steam engine, though obviously many other inventions, like the cotton gin, played a big part. The reason for choosing the steam engine, though, should be obvious — its ability to convert carbon emissions into work with much greater efficiency and on a much larger scale than ever before.

Though there were previous versions of a steam engine, some going back a great many years, the one designed by James Watt in 1781 is considered critical:

In 1781 James Watt patented a steam engine that produced continuous rotary motion.^[3] Watt's ten-horsepower engines enabled a wide range of manufacturing machinery to be powered. The engines could be sited anywhere that water and coal or wood fuel could be obtained. By 1883, engines that could provide 10,000 hp had become feasible.^[4] The stationary steam engine was a key component of the Industrial Revolution, allowing factories to locate where water power was unavailable. The atmospheric engines of Newcomen and Watt were large compared to the amount of power they produced, but high-pressure steam engines were light enough to be applied to vehicles such as traction engines and the railway locomotives.

Anthony Anderson wrote in New Scientist that Watt's improvements to the steam engine "converted it from a prime mover of marginal efficiency into the mechanical workhorse of the Industrial Revolution." Wikipedia adds that the "availability of efficient, reliable motive power made whole new classes of industry economically viable, and altered the economies of continents.[47]"

Pre-Industrial Global Temperature and Pre-Industrial Atmospheric CO2

So the question becomes, not what was the global average temperature in 1900 or the mean of the years 1850–1900, as is usually done, with an implied base year of 1875 — but what was it in, say, 1800, or perhaps, in the mean of the years 1750–1850? In my piece, I argued, along with Michael Mann and others, that the baseline for "pre-Industrial global temperature" was set too high.

That actually matters. Put simply, when people read about global warming, they often see headlines that state "global warming is now +0.6°C above the 1950—1980 mean," or "+0.9°C above 'pre-Industrial temperatures" — statements that lend a kind of comfort to the conversation and strip the problem of its urgency. After all, if the U.N. would like to keep warming to less than +2°C above pre-Industrial temperatures, warming numbers like +0.9°C imply we have a way to go. Even the aspirational warming goal of not more than +1.5°C imply quite a bit of headroom.

My earlier piece argued that the mark "pre-Industrial baseline temperature" was set far too high. (That piece is here: "Global Warming Has Reached Nearly +1.5°C Already.") Briefly, my layman's logic put the actual current global warming at about +1.4°C, and Dr. Mann, using similar but not identical logic, put it at a little more than a tenth of a degree lower. Mann (my bolded emphasis):

It has been widely reported that 2015 will be the first year where temperatures climbed to 1C above the pre-industrial. That might make it seem like we’ve got quite a ways to go until we breach the 2C limit. But the claim is wrong. We exceeded 1C warming more than a decade ago. The problem is that here, and elsewhere, an inappropriate baseline has been invoked for defining the “pre-industrial.” The warming was measured relative to the average over the latter half of the 19th century (1850-1900). In other words, the base year implicitly used to define “pre-industrial” conditions is 1875, the mid-point of that interval. Yet the industrial revolution and the rise in atmospheric CO2 concentrations associated with it, began more than a century earlier. ...

[U]sing the more appropriate 1750-1850 pre-industrial baseline, we see that the Northern Hemisphere average temperature (gray squiggly curve [in Figure 3 at the link]) has already warmed nearly 1.2C. Temperatures have exceeded 1C above pre-industrial levels for most of the past decade.

Mann's Figure 1 at the link shows global warming, not just North American warming, to be greater than what was modeled by the IPCC, closer to +1.3°C or more, using his new baseline.

By either measure, though, Dr. Mann's or mine, global warming has blown well past the +1°C mark, never to return below it without heroic, and hopefully, panic-driven efforts (because at this point, it will take panic to drive a real solution). Frankly, I think we'll blow past the +1.5°C warming mark in just a few years, and I suspect Dr. Mann — and quite a few other scientists, if you asked them privately — would agree. That could be "game over," since with +1.5°C warming present on the ground, +2°C or more would certainly be "in the pipeline," with all the social and political chaos it would bring.

As for global pre-Industrial CO2, the answer is more straightforward and agreed upon. Pre-Industrial atmospheric CO2 is widely considered to have been 280 ppm (parts per million by volume), at the low end of the stable Holocene era range.

Pre-Industrial CO2 is the broad flat blue line above at roughly 280 ppm that starts around 10,000 years B.P. (before the present era) and doesn't begin to rise appreciably until about the year 1800, at which point it shoots up (source; click to enlarge).

We've now reached nearly 410 ppm at this year's monthly peak (up-to-date, interactive NOAA chart here). Not good.

"Truly Uncharted Territory"

From Sabrina Shankman at Inside Climate News, we find this confirmation via a new study (my emphasis):

State of the Warming Climate in 2016: 'Truly Uncharted Territory'

World Meteorological Organization reveals extent of global warming's impacts last year, including epic Arctic melting, drought and extreme weather

The World Meteorological Organization (WMO) released its annual State of Global Climate report on Tuesday, noting a year of broken records and extreme weather events—climate change trends that are continuing into 2017.

"This report confirms that the year 2016 was the warmest on record—a remarkable 1.1 degrees Celsius above the pre-industrial period," said WMO Secretary-General Petteri Taalas. That temperature rise marks a 0.06 degrees Celsius increase over the record set in 2015. The Paris climate agreement commits the world's nations to holding the atmospheric temperature increase to below 2 degrees Celsius, to try to stave off potentially catastrophic global warming.

Average atmospheric carbon dioxide levels hit a record high, at 400 parts per million, and projections for 2017 are even higher. The U.K. Met office recently forecast that this year's monthly CO2 level at Mauna Loa could reach nearly 410 parts per million in May, and the 2017 average could be 2-3 parts per million higher than last year.

"The influence of human activities on the climate system has become more and more evident," wrote Taalas in the report's foreword. "This influence is increasingly being demonstrated by attribution studies for some of the most critical weather and climate extremes, in particular extremes related to heat."

David Carlson, the director of the WMO-sponsored World Climate Research Program, adds, "We are now in truly uncharted territory."

But the news is worse than they say. If you click through to the study itself (pdf here), look at Figure 1 (global temperature), and count from the early low (roughly the year 1860) to the present high, the difference is clearly more than 1.3°C, or where Dr. Mann (and yours truly) place it. In other words, they have not adjusted their definition of "pre-Industrial" temperature. Making that adjustment, their measured data confirms our own.

As I said in the first piece I linked to above (here), "The Paris climate agreement had hoped to hold global warming to no more than +1.5°C above the pre-Industrial temperature. This is not going to happen. We're almost at that point now, and we'll breach that goal in just a few years." Global warming of +1.5°C is dead ahead.

Your next bottom line is my oft-repeated one — it's going to take a revolution or a national panic to get us out of this mess. Or both. An odd set of things to hope for, but the alternative is very much worse.

So here's hoping.

GP