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Far
Worse than Being Beaten with a Hockey Stick: Michael Mann, Our
Terrifying Greenhouse Gas Overburden and Heating the Earth by
+ 2 C by 2036
All that said, Michael Mann laid out some brutal, brutal facts in his Scientific American piece. Ones, that if you only take a few moments to think about are simply terrifying. For the simple truth is that the world has only a very, very slim hope of preventing a rapid warming to at least 2 C above 1880s levels in the near future and almost zero hope altogether of stopping such warming in the longer term.
What does a World That Warms So Rapidly to 2 C Look Like?
OK. That was rough. But what I am about to do is much worse. I’m going to take a look at actual effects of what, to this point, has simply been a clinical analysis of the numbers. I’m going to do my best to answer the question — what does a world rapidly warming by 2 C over the next 22 years look like?
+ 2 C by 2036
21
March, 2014
I’m
going to say something that will probably seem completely outrageous.
But I want you to think about it, because it’s true.
You,
where-ever you are now, are living through the first stages of a
disaster in which there is nowhere to run, nowhere to hide, and no
safe place on Earth for you to go to avoid it. The disaster you are
now living through is a greenhouse emergency and with each ounce of
CO2, methane and other greenhouse gasses you, I, or the rest of us,
pump into the air, that emergency grows in the vast potential of
damage and harm that it will inflict over the coming years, decades
and centuries. The emergency is now unavoidable and the only thing we
can hope to do through rational action is to reduce the degree of
harm both short and long term, to rapidly stop making the problem
worse, and to put human ingenuity toward solving the problem rather
than continuing to intensify it.
But
damage, severe, deadly and terrifying is unleashed, in effect and
already happening, with more on the way.
*
* * * *
(Michael
Mann’s famous Hockey Stick graph showing Northern Hemisphere
temperatures over the past 1,000 years. The influences of human
warming become readily apparent from the late 19th to early 21rst
centuries. But human greenhouse gas forcing has much greater degrees
of warming in store.)
This
week, Michael Mann wrote an excellent piece describing the immediacy
of our
current emergency in the Scientific American.
In typical, just the facts, fashion, he laid out a series of truths
relevant to the current greenhouse catastrophe. These facts were told
in a plain manner and, yet, in a way that laid out the problem but
didn’t even begin to open the book on what that problem meant in
broader context.
Michael
Mann is an amazing scientist who has his hand on the pulse of
human-caused climate change. He is a kind of modern Galileo of
climate science in that he has born the brunt of some of the most
severe and asinine attacks for simply telling the truth and for
revealing the nature of our world as it stands. But though Mann’s
facts are both brutal and hard-hitting for those of us who constantly
read the climate science, who wade through the literature and analyze
each new report. By simply stating the facts and not telling us what
they mean he is hitting us with a somewhat nerfed version of his
ground-breaking Hockey Stick. A pounding that may seem brutal when
compared to the comfortable nonsense put out by climate change
deniers and fossil fuel apologists but one that is still not yet a
full revelation.
I
will caveat what is a passionate interjection by simply saying that
Michael Mann is one of my most beloved heroes. And so I will do my
best to help him out by attempting to lend more potency to his
already powerful message.
2
C by 2036 — Digging through the Ugly Guts of it
All that said, Michael Mann laid out some brutal, brutal facts in his Scientific American piece. Ones, that if you only take a few moments to think about are simply terrifying. For the simple truth is that the world has only a very, very slim hope of preventing a rapid warming to at least 2 C above 1880s levels in the near future and almost zero hope altogether of stopping such warming in the longer term.
The
first set of figures Mann provides involves the current greenhouse
gas forcing. Current CO2 levels are now at the very dangerous 400
parts per million threshold. Long
term, and all by itself, this forcing is enough to raise global
temperatures by between 2 and 3 degrees Celsius.
But hold that thought you were just about to have, because we haven’t
yet included all the other greenhouse gasses in that forcing.
Mann,
in the supplemental material to his Scientific American paper, notes
that the total forcing of all other greenhouse gasses currently in
the atmosphere is about 20% of the total CO2 forcing. This
gives us a total CO2 equivalent forcing of 480 ppm CO2e, which
uncannily mirrors my own analysis here (the
science may have under-counted a bit on the methane forcing, but this
value is likely quite close to current reality for both the short and
long term).
480
ppm CO2e is one hell of a forcing. It is nearly a 75% greater forcing
than 1880s values and, all by itself, is enough to raise temperatures
long-term by between 3.5 and 4.5 degrees Celsius.
And
it is at this point that it becomes worthwhile talking a bit about
different climate sensitivity measures. The measure I am using to
determine this number is what is called the Earth Systems Sensitivity
measure (ESS). It is the measure that describes long term warming
once all the so called slow feedbacks like ice sheet response (think
the giant glaciers of Greenland and West Antarctica) and
environmental carbon release (think methane release from thawing
tundra and sea bed clathrates) come into the equation. Mann, uses a
shorter term estimate called Equilibrium Climate Sensitivity (ECS).
It’s a measure that tracks the fast warming response time once the
fast feedbacks such as water vapor response and sea ice response are
taken into account. ECS warming, therefore, is about half of ESS
warming. But the catch is that ECS hits you much sooner.
At
480 ppm CO2e, we can expect between 1.75 and 2.25 degrees C of
warming from ECS. In essence, we’ve locked about 2 C worth of short
term warming in now. And this is kind of a big deal. I’d call it a
BFD, but that would be swearing. And if there is ever an occasion for
swearing then it would be now. So deal with it.
Mann,
in his article, takes note of the immediacy of the problem by simply
stating that we hit 2 C of shorter term ECS warming once we hit 405
ppm CO2 (485 CO2e), in about two to three years. And it’s important
for us to know that this is the kind of heat forcing that is now
hanging over our heads. That there’s enough greenhouse gas loading
in the atmosphere to push warming 2 C higher almost immediately and 4
C higher long term. And that, all by itself, is a disaster unlike
anything humans have ever encountered.
(Global
annual fossil fuel emission is currently tracking faster than the
worst-case IPCC scenario. Aerosols mask some of the heating effect of
this enormous emission, what James Hansen calls ‘a Faustian
Bargain.’ Image source: Hansen
Paper.)
But
there is a wrinkle to this equation. One
that Dr. James Hansen likes to call the Faustian Bargain.
And that wrinkle involves human produced aerosols. For by burning
coal, humans pump fine particles into the atmosphere that reflect
sunlight thereby masking the total effect of the greenhouse gasses we
have already put into the atmosphere. The nasty little trick here is
that if you stop burning coal, the aerosols fall out in only a few
years and you then end up with the full heat forcing. Even worse,
continuing to burn coal produces prodigious volumes of CO2 while
mining coal pumps volatile methane into the atmosphere. It’s like
taking a kind of poison that will eventually kill you but makes you
feel better as you’re taking it. Kind of like the greenhouse gas
version of heroine.
So
the ghg heroine/coal has injected particles into the air that mask
the total warming. And as a result we end up with a delayed effect
with an extraordinarily severe hit at the end when we finally stop
burning coal. Never stop burning coal and you end up reaching the
same place eventually anyway. So it’s a rigged game that you either
lose now or you lose in a far worse way later.
Mann
wraps coal and other human aerosol emissions into his equation and,
under business as usual, finds that we hit 2 C of ECS warming by 2036
as global CO2 levels approach 450 ppmv and global CO2e values
approach 540 ppmv. At that point, were the aerosols to fall out we
end up with an actual short term warming (ECS) response of 2.5 to 3 C
and a long term response (ESS) of about 5 to 6 C. (Don’t
believe me? Plug in the numbers for yourself in Mann’s climate
model here.)
So
ripping the bandaid off and looking at the nasty thing underneath, we
find that even my earlier estimates were probably a bit too
conservative and Mann, though we didn’t quite realize it at first,
is hitting us very hard with his hockey stick.
What does a World That Warms So Rapidly to 2 C Look Like?
OK. That was rough. But what I am about to do is much worse. I’m going to take a look at actual effects of what, to this point, has simply been a clinical analysis of the numbers. I’m going to do my best to answer the question — what does a world rapidly warming by 2 C over the next 22 years look like?
Ugly.
Even more ugly than the numbers, in fact.
First,
let’s take a look at rates of evaporation and precipitation. We
know that, based on past research, the hydrological cycle increases
by about 6% for each degree Celsius of temperature increase.
So far, with about .8 C worth of warming, we’ve had about a 5%
increase in the hydrological cycle. What this means is that
evaporation rates increase by 5% and precipitation events, on
average, increase by about 5%. But because weather is uneven, what
this does is radically increase the frequency and amplitude of
extreme weather. Droughts are more frequent and more severe. Deluges
are more frequent and more severe.
(Program
in which top climate scientists explain how global warming increases
the intensity of evaporation and precipitation all while causing
dangerous changes to the Jet Stream.)
At
2 C warming we can change this loading from a 5% increase in the
hydrological cycle of evaporation and precipitation to a 12%
increase. You think the droughts and deluges are bad now? Just
imagine what would happen if the driver of that intensity more than
doubled. What do you end up with then?
Now
let’s look at something that is directly related to extreme weather
— sea ice loss. In the current world, about .8 C worth of warming
has resulted in about 3.2 C worth of warming in the polar regions.
And this warming has resulted in a massive and visible decline of sea
ice in which end summer volume values are up to 80% less than those
seen during the late 1970s. This loss of sea ice has had severe
effects on the Northern Hemisphere Jet Stream, both pulling it more
toward the pole and resulting in high amplitude Jet Stream waves and
local severe intensification of storm tracks. At 2 C worth of global
warming, the Arctic heats up by around 7 C and the result is extended
periods of ice free conditions during the summer and fall that last
for weeks and months.
(Actual
rate of sea ice loss vs IPCC model predictions. The most recent
record low value achieved in 2012 is indicated by the dot. Image
source: Assessment
of Arctic Sea Ice/UCAR Report.)
The
impacts to the Northern Hemisphere Jet Stream are ever more severe as
are the impacts to Greenland ice sheet melt. Under such a situation
we rapidly get into a weather scenario where screaming temperature
differentials between the North Atlantic near Greenland and the
warming tropics generate storms the likes of which we have never
seen. Add in a 12% boost to the hydrological cycle and we get the
potential for what Dr. James Hansen describes as “frontal storms
the size of continents with the intensity of hurricanes.”
Greenland
melt itself is much faster under 2 C of added heat and the ice sheets
are in dangerous and rapid destabilization. It’s possible that the
kick will be enough to double, triple, quadruple or more the current
pace of sea level rise. Half foot or more per decade sea level rise
rapidly becomes possible.
All
this severe weather, the intense rain, the powerful wind storms and
the intense droughts aren’t kind to crops. IPCC projects a 2% net
loss in crop yields each decade going forward. But this is likely to
be the lower bound of a more realistic 2-10 percent figure. Modern
agriculture is hit very, very hard in the context of a rapidly
changing climate, increasing rates of moisture loss from soil and
moisture delivery through brief and epically intense storms.
The
rapid jump to 2 C is also enough to put at risk a growing list of
horrors including rapid ocean stratification and anoxia (essentially
initiating a mass die off in the oceans), large methane and
additional CO2 release from carbon stores in the Arctic, and the
unlocking of dangerous ancient microbes from thawing ice, microbes
for which current plants and animals do not have adequate immune
defenses.
How
do we avoid this?
In
short, it might not be possible to avoid some or even all of these
effects. But we may as well try. And this is what trying would look
like.
First,
we would rapidly reduce human greenhouse gas emissions to near zero.
As this happens, we would probably want a global fleet of aircraft
that spray sulfate particles into the lower atmosphere to make up for
the loss of aerosols once produced by coal plants. Finally, we would
need an array of atmospheric carbon capture techniques including
forest growth and cutting, then sequestration of the carbon stored by
wood in lakes or in underground repositories, chemical atmospheric
carbon capture, and carbon capture of biomass emissions.
For
safety, we would need to eventually reduce CO2 to less than 350 ppm,
methane to less than 1,000 ppb, and eliminate emissions from other
greenhouse gasses. A very tall order that would require the sharing
of resources, heroic sacrifices by every human being on this Earth,
and a global coordination and cooperation of nations not yet before
seen. Something that is possible in theory but has not yet been
witnessed in practice. A test to see if humankind is mature enough to
ensure its own survival and the continuation of life and diversity on
the only world we know. A tall order, indeed, but one we must at
least attempt.
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