Are We Headed for Near Term Human
Extinction (NTHE)?
Richard Nolthenius, PhD – Astronomy – Cabrillo
College
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NTEH people like to quote the work of Sam Carana (not a scientist. Arctic
News blog), who created this polynomial fit to 20th century temperature
data. It is meaningless for the future 21st Century. NTHE people believe
these vast extrapolations Above and Beyond the data are a result of good
data analysis. Absolutely False!
--Polynomials are unphysical, are prone to wild excursions, and only
possibly reasonable WITHIN the bounds of the data, which this
extrapolation is not.
If this is the centerpiece of the NTHM thesis, it is not credible!
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Clathrates form and can exist only at high pressure and
low temperature. Any clathrates existing today are at
these conditions.
At 1 C temperature (ocean bottom temps), stable at
pressures corresponding to ~330m ocean depth
This is much deeper than the ~50m depths of the
Siberian Arctic Ocean, or the ~90m depth where rapid
(seasonal) heat transfer can happen through turbulent
mixing.
Therefore, expect heating of clathrates will occur only
slowly.
Arctic Ocean methane releases have NOT been
monitored for long, and are still very small. Most likely
explanation is they have been ongoing for a long time.
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PETM Clathrate destabilization is quite possible here.
But it would take ~ 2,000 years for the heating to reach
and destabilize the clathrates at their stability depth,
although rapid sea level drop or an extraterrestrial
impact could speed this up greatly.
PETM has many hypothetical causes, but there are
significant problems with ALL current explanations,
including the “clathrate bomb” hypothesis.
End Permian Extinction is more dramatic, killing ~95%
of all life on Earth. Associated with massive volcanism
in Siberia – lots of possible mechanisms could work.
Clathrates could be involved, but we just don’t know
enough yet.
Continents very different 250ma, but Siberia at similar
(high and so cold-ish) latitude then as today.
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So for the Methane Apocalypse to play out, you need
massive amounts of methane release in a time scale of
much less than a century.
This looks very unlikely – not just my opinion, but the
judgment of nearly all climate scientists, and
articulated well by Dr. David Archer of U. Chicago – a
geochemist specializing in climate, in RealClimate.org
Methane currently is 1/250th the concentration of
CO2.
So, the Claim: “There is NO QUESTION we have
triggered the Methane Clathrate Gun” is then seen as a
vast extrapolation unsupported by the evidence.
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But it is more likely due to an accelerating
population of ruminants (cows, sheep, etc.)
Added to by an estimated $1.5B in leaks due to
Fracking and the natural gas boom that started
about this time (see “Years of Living
Dangerously” for example).
And also, methane from Arctic tundra, and
occasional local spikes (“dragon breath”) in
methane from Arctic sites, due not to clathrates,
but trapped sediment methane from decaying
vegetation entombed long ago.
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Guy McPherson terms “Self-reinforcing amplifying feedbacks”
But feedbacks must be modelled correctly to get reasonable
answers
e.g. As Arctic Ocean ice goes below 50%, the coefficient in the
feedback term will drop, eventually soon to near zero as there’s
no more ocean ice to melt
Greenland darkening will only go so far, since fresh snow will
continue to fall every winter.
One can’t simply assume every positive feedback takes you to
exponential Final Doom.
While we’re at it: I call on the IPCC Scientists to put into those
~35 Global Climate Models in use around the scientific world,
every climate feedback we know. A good-faith best estimation,
so we are NOT looking just as “what we know for sure”, but
what is the most-likely given all we know.
Some big ones already in: water vapor saturation point, etc.
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The Venus Syndrome worries center around
the following…
Much has been made of a recent paper
showing a plot showing the Habitable Zone for
solar systems, including ours…
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It’s meant to define a very conservative Habitable Zone
around other Main Sequence stars and alien planets.
For this purpose, they use a simple 1-dimensional
climate model and assume a CLOUD-FREE world.
The authors explicitly state that adding clouds will
extend the habitable zone significantly in BOTH
directions. Earth has clouds. Lots of them.
For us, near the inner edge, clouds act mainly to
reflect more sunlight and cool the planet. It’s a
significant effect which moves the inner HZ edge
towards the sun, in a safe direction away from Earth.
The implication that we’re teetering on the edge of a
runaway Greenhouse Venus Syndrome is just wrong.
Climate models all show we are very unlikely to go
that route regardless of our CO2 emissions, for many
millions of years.
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Implication: that since humans have never lived in a +3.5C temperature
world, we’ll all die – but last time the Earth was that hot, we had not yet
evolved as a species – so this is not fair play.
Claim: 440 nuclear reactors around the world will all go into melt-down
with societal collapse. But they CAN be safe-mode’d, if we just try.
Even if not, implication we’ll all die of radiation is gross extrapolation.
Only aragonite (not calcite) species will dissolve in Ocean Acidification.
Other species will take over for dying corals, other perhaps less
beautiful species, alas. But the oceans will not ENTIRELY DIE. Very
bad, but not total Death.
Claim: Sea level rise of 10mm year is a tripling of the past trend.
Sounds VERY scary! But now look at the data on next slide…
Many more ... No time here for them all. Hydro-geologist Scott Johnson
has a good discussion of the many exaggerated claims and
misrepresentations from Guy McPherson’s past talks. Geochemist and
climate expert Professor David Archer at U. Chicago has more, at
RealClimate.org (a website maintained by climate scientists to
communicating to the public on the latest papers and climate claims.
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Kort et al. 2012 find methane release over open waters of the
Arctic Ocean of 2 mg/day/square meter. If you extrapolate
(dangerous!) to the entire Arctic Ocean, that corresponds to 10
million tons/yr of methane. This is almost certainly a significant
overestimate because they say this rate is only seen over open
ocean leads, i.e. it is concentrated because this is where the
methane can escape the ocean into the atmosphere.
If we therefore cut this by approximately the open ocean coverage
fraction over the Arctic, say 30%, you get about 3 million tons/yr.
Compare to 35 billion tons/yr of CO2 from humans, or a factor of
10,000 higher.
Now, this methane release is, and so let’s average over a century
to be roughly representative. At that time scale, methane has
about 20x stronger heating effect than CO2, pound for pound. (It
doesn’t qualitatively change the conclusion below if instead you
use 100x, appropriate for a 10 year average)
We get a final number for the heating effect of recent methane
release rates from the Arctic, of roughly 20/10,000 that of CO2
emissions, or 1/500th of CO2 emissions. Or 1/100th of CO2
emissions averaged over a decade
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Arctic Ocean methane releases need to rise by a
factor of ~100 to become a player comparable to
CO2 in additional greenhouse warming.
On the recent 3 Siberian “methane craters”
which occurred this past summer of 2014: A
calculation of the methane needed to produce
these, by David Archer on RealClimate.org ,
finds it would take 20 million such craters to
produce a “Shakhova Event” (50 gigatons of
methane released all in a few years).
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…As pay-back for Homo Sapien’s wanton
destruction of innocent species. We are
INDEED in Earth’s 6th Great Mass Extinction.
Half or more of all species predicted to be gone
by late this century.
I sympathize with the feeling! Yes I do. But
the reality is –
It is the innocents who will suffer the most in
such a scenario…
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No. Still Grim….
National Academy of Sciences Fellow Professor
Sandra Faber (and co-author with me on several
cosmology papers) gave a recent talk on Earth’s
long term future, at UCSC.
Long term (astronomically long) stable human
population: Very roughly 50 million, which is less
than 1% of today’s 7 BILLION!
21st Century will likely be ugly… but
When asked whether Climate Change would cause
near term Human Extinction – Faber answered
“Not even close!”
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Eating our “seed corn”, basically.
90% of all large fish are already gone
And virtually all arable land on Earth is already
turned to crops. Rainforests mostly cut down for
fast-food burgers (cattle ranches)
We’ve dug deep into our ancient aquifers. Already
250,000 farmers in India have committed suicide
because they cannot afford to dig deeper wells as
aquifers drop (suicide, as a message to all, by
drinking pesticides they also can no longer afford).
This fact has not gotten the wide attention it
deserves.
And financially…..
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This came hot off the presses – some Irish teenage girls
(new winners of the Google Science Fair) appear to
have made a huge breakthrough:
Irish teenagers Ciara Judge, Émer Hickey and Sophie
Healy-Thow, all 16, have won the Google Science Fair
2014. Their project, Combating the Global Food Crisis,
aims to provide a solution to low crop yields by pairing
a nitrogen-fixing bacteria that naturally occurs in the
soil with cereal crops it does not normally associate
with, such as barley and oats.
The results were incredible: the girls found their test
crops germinated in half the time and had a drymass
yield up to 74 percent greater than usual.
OK - Back to grim forecasts….
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Human Civilization has been cradled and
coddled by a 10,000 year period of stable
climate, stable unchanging coastlines, and just
the right amount of ice on the continents
We’re rudely dumping ourselves out of that
cradle, and into the frying pan.
And soon, the Milankovitch cycle insolation
isn’t going to help us stay cooler like it has thus
far, not again for tens of thousands of years.
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Our “To Do” List…
* Grow up! Realize human well-being, not GDP, is the Gold
Standard of virtue. Zero-Growth should be our ultimate
goal, and NEGATIVE growth for some time beginning now.
* Design political empowering systems around Human
Well-Being as the touch-stone. ALL systems in existence
have failed miserably at this.
* Only drastic near-term actions can hope to save us from
probable societal breakdown later.
--- ~0.2 child per family, worldwide
--- Tax-and-Dividend: Motivates EVERYone to adopt lowcarbon lifestyle
--- No reasonable tech fixes will allow us to “Have cake/Eat
too”
But tech fixes still essential:
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Massive deployment of solar PV to replace carbon.
Nuclear perhaps – hard to get unemotional data
and info from either side in THAT debate.
Massive conservation efforts
Pull CO2 from atmosphere (Klaus Lackner’s
artificial trees? Rau process and calcium
bicarbonate? $200/ton I’ve read, but seems
optimistic). Nuclear powered artificial trees?
Reducing atmospheric CO2 to 350 ppm would
require producing a cube of CaCO3 the height of
Mt. Everest, or similar pile of calcium bicarbonate.
Cost? High!! But What’s a Planet Worth?
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Can we DO IT?? It’ll be harder than you think….
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The correlation between the average voter’s
desires and the actual bills passed is
“Miniscule. Statistically insignificant”.
Powerfully financed lobbies run our
government.
Concludes: We are not a Democracy. We’re an
Oligarchy (i.e. run by the tiny minority of
powerful elites. In our case, corporations via
their lobbies)
We Need a Wholesale Change of the make up
of our Representatives in Government
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Rapidly rising food and especially water costs
Resource wars
Have-not countries suffer large loss of life
Possible societal breakdown, but more likely in 2nd and 3rd
World tropical countries than here. It’s already begun.
Nolthenius’ First Law: People Learn the Hard Way.
IF (a BIG IF) we do not suffer societal breakdown in U.S.
and Europe and Japan, then there’s always hope we’ll wake
up and devote a Manhattan Project level commitment to
renewables, and to CO2 removal from the atmosphere,
willing to pay ANYthing to make it happen – this perhaps
by 2050? 2040?
What will the Corporate Overlords do? That’s a big
unknown. If they lose control of elections in the 1st World,
because of massive grassroots revolt, perhaps there’s hope.
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Sidestep the warring Republicans vs. Democrats , who remind me
of the war between Oceania and Eurasia in the classic George
Orwell novel “1984”. A pointless war which is only a distraction
from meaningful action.
My Proposal: Educate – so the People understand the climate
crisis is real, extremely dangerous, and that if we don’t solve it,
nothing else really matters, and urge a Write-In (this is already
legal and unlikely to be repealed) for congressional elections.
Identify in each congressional district someone who will devote
100% to getting a stiff ($300/ton or more) Carbon Tax-AndDividend law enacted, preferably NOT a major party candidate.
And stiff trade sanctions against any other country not joining us.
Tax-And-Dividend is the sole goal of Citizen’s Climate Lobby,
which I recommend to you. It is the single best motivator of
subsequence action to limit carbon.