Earth's thermal regulation balance: 492 W/m2 coming in, 492 W/m2 going out, when we don't mess with it. Diagram from this excellent 1996 paper by U. Wash. Prof. Dennis Hartmann.
Regular readers of HtStW know that I see the consequences of global warming being relative late-comers to the cascade of crises I think will befall
our planet in this century. I expect that our preoccupation with
economic depression, pandemic disease, the end of oil, the exhaustion
of other resources due to overpopulation and waste, and nuclear,
biological and chemical violence will distract us from paying
significant attention to 'natural disasters' precipitated by CO2 until it is far too late. Such disasters may, however, be the icing on the cake that seals the fate of our civilization.
Scientist Tim Flannery's new book The Weather Makers is a tour de force,
an exhaustive and rigorous explanation of how even modest global
warming produces dramatic climate change. It starts with a history of
our planet's climate, describing how natural warming events in the past
have altered Earth's climate, and reviewing how the self-regulating
systems of our ecosphere -- the atmosphere, the oceans, and the
'respirations' of living matter -- keep our planet's climate in a
precarious balance that is as beneficial as possible for all life on
our planet. What comes across in the early chapters is the astonishing
fragility of this ecosystem, and the regularity with which small
meteorites, volcanic eruptions and other events can throw the planet
wildly out of balance and create extinctions of much of life on the
planet. After such extinctions, the complex adaptive system that is our
biosphere (or Gaia if you prefer), acting like a patient builder of
houses of cards, re-starts the building of delicate organic balancing
mechanisms, adapting to the climate changes to produce new and
unpredictable forms of life that are self-sustaining and
self-regulating, until the planet or the cosmos unleashes the next shock to this system.
Flannery
takes pains to explain how utterly complex this balancing act is,
describing the huge difference in temperatures at various levels of our
atmosphere, and how minor tweaking with the tiny constituents of that
atmosphere can either bring about stasis of thermal regulation, or
utterly destroy that stasis. It is now believed that the ice ages were
a consequence of the biosphere not getting the balance quite right,
because some of the variables (Earth's wobble, tilt and distance from
the sun all vary in long cycles) could not be anticipated. So much for
margin for error! We dodged a bullet, Flannery says, when we banned
CFCs a generation ago: had we not, we would already be witnessing some
of the severe consequences of atmospheric imbalance such chemical
meddling produces. And had we used bromine instead of chlorine for the
aerosols that employed CFCs, we would already have irreparably damaged
the atmosphere and Earth would already be in the midst of climate chaos.
The
fragility of this system was brought home to me by an analogy: Our
biosphere -- the membrane of Earth's crust that supports life, is only
10km wide, from the deepest ocean life to the highest mountain life:
were it not for gravity, and air and water pressure, you could travel
its entire width in a leisurely 90 minute walk, or drive it in 5. The
Earth's diameter is 12,700km. If the Earth were shrunk to a soccer-ball
or basketball-sized model, 23cm in diameter, the thickness of the
biosphere in the model would be 2mm -- one mm (1/25") above sea level
and one mm below, and the tiny band in which over 90% of all life
resides would be much narrower still -- invisible to the human eye.
The Keeling Curve, developed by the late Charles Keeling. Image from website
of Dr. Jeff Masters. Flannery says this remarkable chart "shows the
Earth breathing" -- inhaling in the northern spring as new plants
absorb CO2 and exhaling in the northern fall as plants die and decompose.
Human
activity is unbalancing thermal regulation in several ways, Flannery
explains. Burning of hydrocarbons and forests produces CO2 that was previously 'stored' in the ground (each year we burn half a millennium's worth of accumulated hydrocarbons), releasing that CO2
into the atmosphere. In addition, chemicals we release into the air
damage the ozone layer, allowing more of the sun's heat to reach the
Earth. And, as the oceans become more acidic as they have to absorb
more CO2, they, and the burned and acidified forests, become
less able to act as 'carbon sinks', allowing more of the carbon in the
air to escape back into the atmosphere. "Positive feedback loops"
(vicious cycles) hence accelerate the imbalance and the climate change
consequences.
One interesting period to study, says Flannery, is
the period of sudden global warming that occurred 55 million years ago,
at the time of the clathrate release (methane from underground being
released by tectonic shifts and sparked into flame by volcanic heat
under the oceans). In that instance, the carbon was mostly absorbed by
the oceans rather than reaching the atmosphere, but the resultant spike
in CO2 in the oceans exterminated most marine life and left
the oceans heavily acidic for 20,000 years. While not an exact parallel
to today's human-caused CO2 spike, the rate of increase is comparable, and the consequences, this 'last time around', were cataclysmic.
As a consequence of global warming thus far, all non-human life
is, on average, migrating towards the poles at a rate of 6km each
decade, and that pace is accelerating. This has resulted in significant
havoc to local ecosystems everywhere: Extinctions in tropical areas,
invasions by new species in temperate and polar areas, and massive
turmoil to established species. And thanks to El Niños and La Niñas,
global warming and climate change are occurring not smoothly but in
unpredictable, erratic spurts -- most recently in 1976 and 1998, when
average ocean temperatures in the Pacific suddenly spiked and have not
subsided.
I shivered when I read that one of the species that is
threatened by this migration is the harp seal, being slaughtered en
masse as I write this thanks
to the morons in the Canadian federal and Atlantic provincial
governments. The breakup of sea and gulf ice, earlier each year, and in
some cases non-formation of ice at all
(notably in 5 of the last ten years) in breeding areas in Canada's
Atlantic region is preventing the harp seals from breeding, and
Flannery explains that an extended run of pupless years is now to be
expected, and will lead to the harp seal's extinction. Ironically, this
year's hunt will have to be extended, it was announced today, because
there are fewer seals than expected and because it is harder for the
'hunters' to reach them due to early breakup and non-formation of the
ice this year. Canada's polar bears, natural predators of the
seals that have long fled the area for more northern areas, are, it was
reported this week, also struggling with lack of sea ice and unable to
reach their prey, and are starving to death, also headed for
extinction. We Canadians should be ashamed of ourselves, and furious at
our governments, for tolerating this. The new minority Harper
government has also promised to renege on Canada's Kyoto commitment.
Flannery
next painstakingly connects global warming and climate change to
current polar melting, reef destruction, ocean current changes,
droughts, drops in and salinization of the water table, and species
extinctions. He says there is now evidence that the disastrous
desertification of the vast sub-Saharan Sahel region of Africa, from
the west coast to Darfur and Somalia, is due more to climate change
(rainfall patterns) than to overgrazing and poor soil management.
There
are three possible 'vicious cycle' effects of global warming that could
lead to very sudden and disastrous climate change, Flannery says. In
declining order of probability:
- Collapse of the Gulf Stream (and its moderating influences on climate in most of the world)
- Collapse and desertification of the Amazon Rainforest
- A new clathrate methane release from the ocean floor
Even
if none of these occur, he says, accelerating effects of global warming
could soon reach a 'tipping point' at which no amount of human action
could prevent it from continuing to the point our planet would become
unlivable. He sees three possible scenarios as we attempt to come to
grips with this reality:
- Too late, inadequate or
uncoordinated response: Leading to massive climate shifts, destruction
of Earth's life support systems, and destabilization of civilization,
leading to a Dark Ages where "the most destructive weapons ever devised
will still exist, while the means to regulate their use and make peace
will have been swept away", starting as soon as 2050.
- Coordinated, prompt, individual, national and corporate response, including global adoption of a Contraction & Convergence Convention, leading to a 70% reduction in CO2 emissions from human activity by 2030, the gradual elimination of all CO2-producing
energy after that, and sustaining carbon monitoring and reduction for
at least the century thereafter needed to restore the planet's thermal
self-regulating ability.
- Half-hearted response, sufficient to
prevent only immediate crises, which would then have to be followed by
centuries of massive, staggeringly expensive, global climate
engineering projects to help the planet manage the carbon cycle.
I
was dreading reading Flannery's prescription because there were early
clues that he believes, based in part on how quickly CFCs were banned a
generation ago, that massive coordinated action, combining
unprecedented government activity with a global groundswell of voluntary personal actions
on eleven fronts, is possible. I'm not sure if he says this because
he's naive (both because human beings and governments don't act this
quickly or decisively unless the threat is imminent and personal, and
because there simply isn't enough top-down control in our world to
mandate, control and coordinate such action even if we wanted it), or
because he didn't want the book to be a 'downer', hurting sales and the
probability of people at least trying to achieve what he prescribes.
Whatever
his motivation for saying this, it left me extremely discouraged. As
Einstein suggested in his statement on nuclear weaponry, the more we
know, and the more we know about human nature, the more pessimistic we
get about our ability to collectively take responsibility for our
actions and act in accordance with our collective interest. Flannery
himself acknowledges that the US and Australia are two countries that
are among the most vulnerable to the effects of climate change, but
their governments haven't even signed Kyoto, an accord which Flannery describes
as hopelessly inadequate. And the idea, which Flannery advances late in
the book, that corporations and governments could be pressured into
action on global warming by the threat of lawsuits once the connection
between carbon emissions and the negative effects on health, security
and climate have been even more convincingly established, is, to
me, absurd. One need only look at how well Big Tobacco is still doing
to see that such threats don't work.
In summary, this is an
important book, a work of true science, and a must read for anyone who
cares about future generations or the health and sustainability of our
planet. But rather than instilling new hope and galvanizing billions
into action to deal with this huge challenge, I suspect Flannery's book
may well be, a century from now, the final epitaph for our civilization.
I
will of course act personally on the eleven voluntary personal actions
hotlinked above, and encourage everyone to do likewise. Alas, as I've
said before, our human nature is not to do what we can, but rather to do what we must. |
MADE IN CANADA
trust your
instincts 
