The Climate-Change Dog That Did Bark In The Night: CO2 Continues Its Unprecedented 6-Month Streak

In one of Conan Doyle’s Sherlock Holmes mysteries, an apparent theft of a racehorse is solved when Holmes notes “the curious incident of the dog in the night” – the point being that the guard dog for the stable did not bark, showing that the only visitor was known and trusted.  In some sense, CO2 is a “guard dog” for oncoming climate change, signaling future global warming when its increases overwhelm the natural Milankovitch and other climate cycles.  It is therefore distressing to note that in the last 6 months, the dog has barked very loudly indeed:  CO2 in the atmosphere has increased at an unprecedented rate. 

And this is occurring in the “nighttime”, i.e., at a time when, by all our measures, CO2 emissions growth should be flat or slowing down.  As noted in previous posts, efforts to cut emissions, notably in the EU and China, plus the surge of the solar industry, have seemed to lend credibility to metrics of carbon emissions from various sources that suggest more or less flat global emissions in 2014 and 2015 despite significant global economic and population growth.

What is going on?  I have already noted the possibility that a major el Nino event, such as occurred in 1998, can cause a temporary surge in CO2 growth.  In 1998, indeed, CO2 growth set a record that was not beaten until last year, but in the two years after 1998, CO2 atmospheric ppm growth fell back sharply to nearly the previous level.  By our measures, the el Nino occurring in the first 5 months or so of 2016 was about equal in magnitude to the one in 1998, so one would expect to see a similar short surge.  However, we are almost 4 months past the end of this el Nino, and there is very little sign of any major decrease in growth rate.  It already appears certain that we cannot dismiss the CO2 surge as a short-term blip.

Recent Developments in CO2 Mauna Loa

In the last few days, I was privileged to watch the video of Prof. John Sterman of MIT, talking about the “what-if” tool he had developed and made available in which climate models drive CO2 emissions growth depending on how aggressive the national targets are for emissions reduction.  He was blunt in saying that even the commitments coming out of the Paris meeting are grossly inadequate, but he did show how much more aggressive targets could indeed keep total growth at 2 degrees C.  In fact, he was so forthright and well-informed that I could finally hope that MIT’s climate-change legacy would not be the government-crippling misinformation of that narcissistic hack Prof. Lindzen.

However, two of his statements – somewhat true in 2015 but clearly not true at this point in 2016 (the lecture, I believe, was given in the spring of 2016) – stick in my head.  First, he said that we are beginning to approach 1.5 degrees C growth in global land temperature.  According to the latest figures cited by Joe Romm, the most likely global land temperature for 2015 will be approximately 1.5 degrees C.  Second, he said that CO2 (average per year) had reached the 400 ppm level – a statement true at this time last year.  As of April-July 2016, however, the average per year has reached between 404 and 405 ppm.

CO2 as measured at the Mauna Loa observatory tends to follow a seasonal cycle, with the peak occurring in April and May, and the trough in September.  In the last few years, at all times of the year, growth year-to-year (measured monthly) averaged slightly more than 2 ppm.  Note that this was true for both 2014 and most of 2015.  Then, around the time that the el Nino arrived, it rose to 3 ppm.  But it didn’t stop there:  In April, a breathtakingly sharp rise of 4.1 ppm took CO2 up to 408 ppm.  And it didn’t stop there:  May and June were likewise near 4 ppm, and the resulting total average rise through August has been almost 3.6 ppm.  September so far continues to be in the 3.3-3.5 range. 

CO2, el Nino, Global Land Temperature:  What Causes What?

Let’s add another factoid.  Over the last 16 or so months, each month’s global land temperature has set a new record.  In fact, July and August (July is typically the hottest month) tied for absolute heat record ever recorded, well ahead of the records set last year.

So here we have three factors:  CO2, el Nino, and variations in global land temperature.  Clearly, in this heat wave “surge”, the land temperature started spiking first, the full force of el Nino arrived second, and the full surge in CO2 arrived third.  On the other hand, we know that atmospheric CO2 is not only a “guard dog”, but also, in James Hansen’s phrase, a “control knob”:  in the long term, for large enough variations in CO2 (which can be 10 ppm in some cases), the global land temperature will eventually follow CO2 by rising or falling in proportion.  Moreover, it seems likely that el Nino’s short-term effect on CO2 must be primarily by raising the land temperature, which does things like expose black carbon on melting ice for release to the atmosphere, or increase the imbalance between carbon-absorbing forest growth and carbon-emitting forest fires by increasing the incidence of forest fires.

But I think we also have to ask whether the effect of increasing CO2 on global temperatures (land plus sea, this time) begins over a shorter time frame than we thought.  The shortest time frame for a CO2 effect suggested by conservative science is perhaps 2000 years, when a spike in CO2 caused Arctic melting indicative of global warming less than a million years ago.  Hansen and others, as well, have identified 360 ppm of atmospheric CO2 as the level at which Arctic sea ice melts out, and we only passed that level about 20 years ago – a paper by a Harvard professor projects that Arctic sea ice will melt out at minimum somewhere between 2032 and 2053.  In other words, we at least have some indication that CO2 can affect global temperature in 50-100 years or so.

And finally, we have scientific work showing that global land temperature increases that melt Arctic sea and land ice affect albedo (e.g., turn white ice into blue water), which in turn increases sea and land heat absorption and hence temperatures, and these changes “ripple down” to the average temperatures of temperate and subtropical zones.  So part of global land temperature increase is caused by – global land temperature increase.  It is for these reasons that many scientists feel that climate models underestimate the net effect of a doubling of CO2, and these scientists estimate that rather than 500 ppm leading to a 2 degree C temperature increase, it will lead to a 4 degree C increase.

I would summarize by saying that while it seems we don’t know enough about the relationship between CO2, el Nino, and global land temperature, it does seem likely that today’s CO2 increase is much more than can be explained by el Nino plus land temperature rise, and that the effects of this CO2 spike will be felt sooner than we think.

Implications

If the “guard dog” of CO2 in the atmosphere is now barking so loudly, why did we not anticipate this?  I still cannot see an adequate explanation that does not include the likelihood that our metrics of our carbon emissions are not capturing an increasing proportion of what we put into the air.  That certainly needs looking into.

At the same time, I believe that we need to recognize the possibility that this is not a “developing nations get hit hard, developed ones get by” or “the rich escape the worst effects” story.  If things are happening faster than we expect and may result in temperature changes higher than we expect, then it is reasonable to assume that the “trickle-up” effects of climate change may become a flood in the next few decades, as rapid ecosystem, food, and water degradation starts affecting the livability of developed nations and their ability to feed their own reasonably-well-off citizens. 

The guard dog barks in the night-time, while we sleep.  We have a visitor that is not usual, and should not be trusted or ignored.  I urge that we start paying attention. 

CO2 and Climate Change: Our Partial Data Promises Hope, Our Best Measure Insists Alarm

For the last five years or so, I have been watching the measures of atmospheric carbon as measured at the peak of Mauna Loa in Hawaii (where contaminating influences on measurements are minimal).  I have become accustomed to monthly reports where CO2 has increased a little more than 2 ppm over the same month the previous year.  This year, things have changed drastically.

On Wed. Apr. 13, for example, I found that (a) monthly CO2 last month had increased by 3.6 ppm year to year; (b) the previous three days had been recorded as about 409.4, 409, and 408.5 ppm, of which the first measurement was about 5 ppm above the same day last year and about 10 ppm above the monthly average 1 ½ years ago, and (c) last year’s average increase had been confirmed as 3.05 ppm, breaking the record set in 1998 for greatest CO2 increase (the data from Mauna Loa go back to 1959).

[UPDATE:  3 weeks ago was the first weekly average above 405 ppm.  Last week was the first weekly average above 406 ppm.  This week was the first weekly average above 408 ppm – 4.59 ppm above the same week last year]

Meanwhile, figures gathered by IEA suggest that fossil-fuel carbon emissions essentially were flat over the 2014-15 time period.  Other studies by CarbonTracker suggest that other net sources and sinks of atmospheric carbon (uptake by the land and the oceans taking carbon from the atmosphere, “fire” [e.g., forest fires on land] acting as a source of atmospheric carbon) have been essentially flat for 15 years or more. 

What is going on?  Why the apparent large rise in Mauna Loa CO2 growth rates over 2014-16 and the apparent flat rate of growth in atmospheric carbon in 2014-15 according to IEA’s data supplemented by CarbonTracker?   Far more importantly, why does the first seem to signal an alarming development in global warming, while the second seems to promise that our efforts in sustainability and global compacts to combat global warming are beginning to bear fruit? And finally, which is right?

[Note:  Because of time constraints, I won’t be able to discuss things in depth.  However, I feel it is important that readers understand the general reasons for my conclusions]

Implications of Hope and Alarm

Let’s start with the second question:  Why does the IEA data seem to offer hope of significant progress in combating global warming, while the Mauna Loa CO2 data seems to signal alarm about the progress of global warming?
If the IEA is right, then over the last 2 years we have begun to make significant progress on reducing fossil-fuel pollution – despite a global economy that grew significantly in 2014 and 2015.  The result is that the rate of growth of CO2 has been flat the last two years.  Because of the recent global climate agreements, we can expect future years to slow the rate of growth, and in the not-too-distant future to begin to actually decrease atmospheric CO2.  Optimistically, we can hope to reach atmospheric stasis at 500 ppm, which will not keep global warming below 2 degrees C, according to Hansen and others, but should keep it below 4 degrees C, where the consequences become much worse.

If the ML CO2 data is right, then we are not only making no significant progress in combating global warming, we may very well be at the start of more rapid warming.  For the last 15 years or so, the rate of growth of atmospheric CO2 has been slightly more than 2 ppm (the previous 15 years saw a growth rate slightly more than 1.5 ppm per year).  A bit more than 2 ppm per year for 15 years translates into about 1 degree Fahrenheit of average global warming.  If we now shift to a bit more than 2.5 ppm per year, that should translate into about 1.3 degrees Fahrenheit of warming over the next 15 years.  It will also mean that we “bake in” 2.67 degrees C of warming since 1850, most of it in the last 60 years, and will be well on the way to about 4 degrees C of warming (blowing past 500 ppm easily) by the 2050-2060 time frame, if we continue with present efforts rather than increasing them.

Which Is Right?

Now let’s tackle questions 1 and 3:  what are the characteristics of the IEA and ML data that lead them to apparently different conclusions, and which of the two is more likely to be right?

Start with the IEA data on fossil-fuel emissions per year.  IEA depends primarily on self-reporting by nations of their use of electricity and heating, supplemented by extrapolation based on prior experience of the amount of CO2 released by coal/gas/oil-based heating and electricity generation. 

There are several reasons to view this data as likely to underestimate actual fossil-fuel emissions, and likely to have that underestimate increase over time.  First, the IEA data does not cover emissions during fossil-fuel production and refining.  The upsurge in fracking would show up in the IEA data as a net decrease in pollution (switching from use of oil to natural gas), while independent studies of wellhead-to-shipment emissions suggest that their total use-plus-produce emissions are almost equivalent to that of oil.  Second, there has been an ongoing shift in business’ fossil-fuel use from Europe/the US to developing countries like China and India.  Not only is these countries’ ability to report the full amount of fossil-fuel emissions less, they are probably less efficient in using fossil fuels to heat and generate electricity in comparable facilities – and the IEA appears to apply the same efficiency standards to comparable facilities in both places.

Now let’s turn to the Mauna Loa CO2 data.  Long experience has determined that any additional CO2 detection from nearby sources is transitory and will wash out in the monthly average.  Likewise, on average, Mauna Loa tracks near the center of Northern Hemisphere response to fossil-fuel emissions primary sources, and can be cross-checked against a global CO2 measure which is one month behind in reporting but has been showing a comparable upsurge (3.4 ppm in February). [Note:  The IEA shows 0% increase in fossil-fuel emissions in 2015, while global and Mauna Loa data show a 0.75% increase in total CO2 emissions]

What are possible causes of the discrepancy aside from underestimated emissions data?  There could be increased “oceanic upgassing” as melting of sea ice allows release of carbon from plants in the newly exposed ocean – not likely, as it is an effect not clearly detected before.  There could be decreased “uptake” from the oceans as they reach their capacity to absorb carbon from the air – but such an uptake slowdown should happen more gradually.  And then there is the el Nino effect.

I haven’t found a good explanation yet of just how el Nino affects CO2 positively, much less how it affects CO2 proportionally to the strength of the effect.  However, the largest recorded el Nino up to this time happened in 1998, data indicate that the 2015-16 el Nino is about as strong, and the 1998 el Nino produced approximately the same outsized jump in CO2 relative to the previous year as the 2015-2016 one has, according to the helpful folks at Arctic Sea Ice (neven1.typepad.com).  So Mauna Loa recent data could be explained as (constant underlying CO2 growth rate) plus (2015-2016 el Nino effect). 

However, aside from all the reasons cited above for being mistrustful of the IEA data, there is another reason to feel that fossil-fuel emissions have actually been going up as well: 1996-99 were years of big economic growth almost certainly leading to large increases in fossil-fuel emissions and thus the underlying CO2 growth rate.  In other words, to be truly compatible with 1998, the equation more likely should be (constant underlying CO2 growth rate) plus (significant 2013-16 increase in fossil-fuel emissions and hence CO2 growth rate) plus (2015-16 el Nino effect).

All this reminds me of the scene in Alice Through the Looking-Glass where Alice starts walking towards her destination and finds herself further away than before.  You have to run much faster to stay in the same place, another character tells her, and much faster than that to get anywhere.  I view it as more likely than not that we are continuing to increase our fossil-fuel contribution, and that we will have to run much harder to keep the CO2 growth rate flat, much harder than that to start the growth rate decreasing, and much harder even than that to begin to decrease overall CO2 any time in the near future.

Facts and the Habit of Despair

In one of Stephen Donaldson’s first books, he imagines a world beset by evil whose only hope is a leper from Earth.  In those days, leprosy had no treatment and the only way for lepers to survive was to constantly survey oneself to detect injuries that dead leprous nerves failed to warn oneself of, every waking second of every day – to constantly face one’s facts.  In the new world, he tells the leader of the fight against evil “You’re going to lose! Face facts!” The leader, well aware that only the leper can save his world, says very carefully, “You have a great respect for facts.”  “I hate facts,” is the response.  “They’re all I’ve got.”

I have concluded above that it is more likely than not that fossil-fuel pollution and therefore the underlying CO2 growth rate continues to grow – and that appears to be the fact delivered by the best data we have, the Mauna Loa and global CO2 measurements.  I hate this fact; but it seems to be what we have. 

And yet, Donaldson’s same series delivers an additional message.  At its improbable world-saving end, the leper asks the Deity responsible for his being picked why he was chosen.  Because, says the Deity, as a leper you had learned that it is not despair, but the habit of despair, that damns [a leper or a world].  To put it in global warming terms:  Yes, the facts are not good.  But getting into the habit of giving up and walking away in despair whenever you are hit by these facts is what will truly damn our world.  Because the horrible consequences of today’s facts are only a fraction of the horrible consequences of giving up permanently because of today’s facts.

To misquote Beckett:  I hate these facts.  I can’t go on.

I’ll go on.

Some Fascinating If Minor Effects of the Ocean and the Air on Global Warming

Over the last four years, I have seen some reports on scientific research into climate mechanisms involving the ocean and the atmosphere (lower and upper) that I regard as both fascinating and (apparently) often misunderstood.  So here’s a quick note on what I understand in general to be the import of these mechanisms.  As always, there will probably be mistakes in my summary:  Caveat lector.

The Fate of Greenland

That actually was the title of a book by (iirc) MIT researchers that summarized the first, and imho most major, of these mechanisms.  It works like this:  warm surface water flows in the Gulf Stream current northeast.  Off Greenland, it dives down to the deep ocean, and becomes a current flowing south through the Atlantic.  When it reaches Antarctica, it flows as a current halfway around the world and starts flowing north again, to surface somewhere around the Bering Strait – a journey of maybe 100-150 years.  This current is therefore continually refreshing the warmth of the deep ocean, and is one mechanism by which the heat of the surface water is transmitted to the deep ocean.

What causes the Gulf Stream to sink is that it becomes relatively salt-heavy compared to the water around it.  However, periodically, when temperatures get too warm, sea ice in the area melts.  Sea ice when it originally forms expels the salt; when it melts, therefore, it releases relatively non-salty water – and the Gulf Stream stops sinking.  This, in turn, stops the ocean “conveyor” of deep-water heat and, 100-150 years later, stops the warming of the Bering Strait (and therefore Arctic) water as well – which causes the water around Greenland to cool again and the Gulf Stream to dive again.  You may remember that this is the phenomenon that caused many to fear just such a Gulf Stream failure due to global warming – and so you had doomsday predictions of a collapse of temperatures in northern North America and northern Europe, which are today warmed beyond their latitude by the Gulf Stream.  Alas, all indicators are that such a stoppage, if it is happening, is happening only slowly, and by the time the Gulf Stream stopped a rise in temperature that would more than compensate may well have happened.

So how has this ocean current played into global warming so far?  I believe it has played a minor but significant role in Arctic melt.  Bear in mind that Arctic sea ice never extends to the bottom of the Arctic sea, and below it is salt-heavy water that flows (bearing the ice with it) more or less from the Bering Strait across the North Pole to Greenland and Iceland and the North Atlantic.  The warming of 1910 is now surfacing in the Bering Strait and going to warm the ice in the Arctic from below and the side – a small warming, according to measurements in the Bering Strait, but I believe a significant factor in the melting of Arctic sea ice we have seen over the last 20 years, along with increased summer heat melting the ice from above.  That effect, while still minor, can only increase as, over the next 50 years, we begin to enter the period of more rapid ocean-surface/Gulf-stream warming from 1913-1963. And, of course, the warming of the waters around Greenland will grease the skids of Greenland’s land glaciers, accelerating the raising of ocean levels.

Boys, Girls, and Oscillations

By now, probably, many have heard of the El Nino (“the boy”) effect, and some of the contrary La Nina (“the girl”) effect.  Briefly, periodically an unusually warm ocean-surface current (el Nino) arrives in Ecuador from the Pacific.  This is the crest of a decade-long or so period when this current is unusually warm.  Likewise, periodically an unusually cool current (la Nina) arrives, and is the trough of a decade-long or so period when this current is unusually cool.

The ripple effects of an el Nino are global.  We see higher global temperatures, especially in places like the US western seacoast.  It may affect a characteristic of the northern latitudes called the North Atlantic Oscillation (basically the location of a place of low [?] pressure in the Atlantic near/in the Arctic), which when “positive” brings hotter weather to northern Europe and cooler weather to North America, and when “negative” brings cooler weather to northern Europe and hotter weather to North America.  An el Nino seems to be mostly associated with a “positive” NAO, and a la Nina with a “negative” NAO.

A recent study shows that in the period of today’s global warming, an el Nino period corresponds to 10-20 years of accelerated global warming, and a la Nina period to 10-20 years of “hiatus”, meaning no or slower global warming.  Over the last fifteen years, we have seen a hiatus period following an unusually strong el Nino in 1998, plus acceleration in underlying global warming.  Thus, although we have not broken the 1998 global temperature record, we are continuing to see global temperatures rise from year to year, from 1999 onwards.  What is worse, the la Nina period should be coming to its end – indeed, some expected it to end in 2012.  It is possible that global warming’s effects on ocean-surface and deep-ocean warming may have disrupted the timing of el Nino – but, failing that, what we have seen over the last 15 years may have been a relatively halcyon period.

The other interesting finding from this study and a previous one is that el Nino has an effect not only on weather patterns, but also on the ocean – more specifically, on transmission of heat from the ocean’s surface to the deep ocean.  The off-Greenland “heat sink”, it turns out, is only one of four such transmission places from surface to deep ocean, one in the Northern Pacific, one in the southern Pacific near Antarctica, and one in the southern Atlantic near Antarctica.  In all of these places, the wind patterns essentially form an ellipse around a center.  El Nino affects these winds such that transmission to the deep ocean decreases, and there is more surface heat and less deep-ocean heat, and la Nina makes the transmission increase, so that there is more deep-ocean heating and less of the surface heat that contributes to global warmth.  Note also that global-warming-driven greater energy in the circum-Antarctic current may have actually increased the “heat sink” there, slowing global warming independently of the el Nino effect, but no one is quite sure of that one. 

So what we have so far is a longer-term (100-150 years) ocean global-warming effect that over the next 100 years will become more and more serious, plus a decades-long oscillation that over the long term has zero effect on global warming but can deceive you about the trend – if you let it.

Mongolian Weirding

OK, this one is based a bit on preliminary research, and is the least important in the medium and long terms as regards global warming.  But it’s so weird …

As I understand it, it begins when the temperature somewhere above the Tarim desert “basin” near Mongolia warms just enough to allow the heat of that basin to rise towards the troposphere (upper atmosphere).  That warming is automagically transmitted northward to the Arctic, where for some reason the transmission of heat to the troposphere removes much of the heat-trapping ozone there (?).  As a result, especially in winter, the Arctic actually becomes colder, and this in turn propels a greater differential with temperatures farther south.  This, in turn, means that the jet stream, which operates in the troposphere, fluctuates more north and south, and this in turn causes more frequent intrusion of cold Arctic temperatures to the south.  Hence, apparently, last winter.  And we can blame it all on Mongolia …

Apparently, because of global warming that effect has been happening more often.  And yet, compared to the other effects I’ve discussed, in the medium and long terms this is pocket change.  So, the jet stream oscillates more often; but the Arctic is also warming much faster than everywhere else, to the tune of 10-20 degrees Fahrenheit in the winter, so the effects of jet-stream-induced cold from the Arctic are steadily being muted.  Clearly, as the incredibly warm North American winter of two years ago shows, in the medium term Nino/Nina and the NAO dominate, and in the long term CO2-induced global warming dominates. But the Mongolian effect is just so weird …

Prehistorical Minimum

I see a few who in analyzing these effects attempt to apply a simplistic rule:  “The last time this happened …” As in, the last time we reached 400 ppm the Arctic was ice-free year-round, and the seas were 100 feet higher.  Referring to the past, in the case of these three effects, is likely to understate global warming and its effects over the next 100 years. 

For example, beyond perhaps 10 million years ago there was no join between North and South America, and therefore the Pacific el Nino probably flowed directly through the Atlantic until it hit Europe, while there was probably no Gulf Stream.  Was there therefore less of a “Greenland heat sink” in those days?  Probably, but it was far outweighed by the relative slowness of the CO2 increase in a Milankovitch cycle or a undersea-volcano-driven CO2 increase, and also outweighed by the ability of weatherization and the like to catch up to and counteract CO2-driven increases in ocean-surface temperature. 

For another thing, there was an open question a decade ago about the rate of global warming for a certain amount of CO2 – this discussion of “heat sinks” seems to have ended most of the uncertainty.  In other words, one could look at the rate of warming and, depending on the rate in which heating went into the ocean surface and into the deep ocean, come up with a wide range of estimates for directly CO2-driven global warming.  Well, now we appear to know that we were looking during a period of unusual la-Nina-driven deep-ocean heating, and therefore our estimates of CO2 “forcing” are narrowing in on the high side of the estimate range.  Not good news …

So I guess my overall message is that most of these effects have served in the past to allow some to underestimate the seriousness of global warming.  Now that we know them, their effects are clearly fascinating but minor in the grand scheme of things.  Fun to write about; but let’s not take our eyes off the prize.  If we do, that prize will likely be Pandora’s box – without the Hope.