BOOK REVIEW
Goodness, Gracious, Great Balls of Gaia!
Brian Hayes
The Revenge of Gaia: Earth's Climate Crisis and the Fate of
Humanity. James Lovelock. Foreword by Sir Crispin Tickell. xiii
+ 177 pp. Basic Books, 2006. $25.
The Revenge of Gaia: The title of James Lovelock's new book
calls to mind the fourth or fifth sequel of some horror movie, one
with a monster that rises from the sea to maul Tokyo or New York.
This mental image is not altogether inappropriate. The book is in
fact a sequel, following several earlier titles by the same author:
Gaia, The Ages of Gaia, Healing Gaia,
Homage to Gaia. Furthermore, it is a horror
story, meant to frighten us. Tokyo and New York and hundreds of
other cities are in grave danger, Lovelock warns. And, as in most
horror flicks, the real villain is not the tormented monster but
human arrogance and greed.
For the benefit of those who have not been following along through
the earlier reels of this long-running saga, I'll give a thumbnail
summary. Lovelock (together with Lynn Margulis) first proposed more
than 30 years ago that the physical environment at the Earth's
surface and the life-forms that inhabit the planet interact and
coevolve to maintain a steady state. Various feedback loops and
homeostatic mechanisms regulate climate and the chemistry of the
atmosphere, providing a habitat that is both milder and more stable
than what would be found on a lifeless planet at the same distance
from the Sun. Stated in these terms, Lovelock's idea is provocative
but not highly controversial; however, Lovelock does not state his
thesis in quite these terms. As he tells it, the Earth and its
residents don't merely interact but rather collaborate, actively
working toward the common goal of maintaining a favorable
environment for life. In Lovelock's account, the
"geophysiological" system is endowed with a will and a
personality, not to mention a gender. She is Gaia, named for the
Greek goddess of Earth, and her character seems to alternate between
fairy godmother and beleaguered landlady; Margulis has called her a
"tough bitch."
Lovelock is coy about just how seriously we should take his
personification of the planet and biosphere. Revenge, like
some of the other books, includes a disclaimer: "You will
notice I am continuing to use the metaphor of ‘the living
Earth' for Gaia; but do not assume that I am thinking of the Earth
as alive in a sentient way, or even alive like an animal or a
bacterium. . . . It has never been more than metaphor—an
aide pensée, no more serious than the thoughts
of a sailor who refers to his ship as ‘she.'" Yet
elsewhere in the book, scores of other passages speak in such clear
and unqualified terms of Gaia's motives and goals and struggles and
emotions that the veil of metaphor becomes rather flimsy and
tattered. The book's glossary (which one might suppose would be
definitive) says this of "Gaia theory":
A view of the Earth that sees it as a self-regulating
system made up from the totality of organisms, the surface rocks,
the ocean and the atmosphere tightly coupled as an evolving system.
The theory sees this system as having a goal—the regulation of
surface conditions so as always to be as favourable as possible for
contemporary life.
For many readers, this teleological insistence on goals raises a
steep barrier to the acceptance of Lovelock's ideas. Toward the end
of Revenge, Lovelock writes:
I know that to personalize the Earth System as Gaia, as I
have often done and continue to do in this book, irritates the
scientifically correct, but I am unrepentant because metaphors are
more than ever needed for a widespread comprehension of the true
nature of the Earth and an understanding of the lethal dangers that
lie ahead.
I guess I must be among the scientifically correct, because I do
find this habit irritating. And yet still I want to salvage what I
can from this farrago of metaphors gone berserk, because Lovelock is
not a crank, or not only a crank; he's quite a creative thinker.
In the 1960s Lovelock was working with a team at the Jet Propulsion
Laboratory on methods of searching for life on Mars. Most of the
effort was focused on instruments to be sent on spacecraft, but
Lovelock had a shrewder plan: If life were abundant on Mars, he
noted, we could detect it from right here, merely by examining the
optical spectrum (and hence the chemical composition) of the
planet's atmosphere. In science fiction, planets are dismissed as
uninhabitable because their air is unbreathable; Lovelock turned
this formula upside down, asking not whether the Martian atmosphere
could support life but whether it showed signs of having been
altered by the presence of life. Living things tend to upset
chemical equilibrium. The atmosphere of an inhabited planet will be
supercharged with reactive elements such as oxygen; in the absence
of ongoing biological activity, these substances will eventually
break down or recombine into more-inert forms, most notably carbon
dioxide. The prevalence of carbon dioxide and the absence of oxygen
in the Martian atmosphere were the planet's death certificate.
Turning the same observational method on the Earth tells us
something important about life here at home: This would be a much
different planet, even in its physical and chemical aspects, without
its encrustation of living organisms. Biologists tend to emphasize
how well plants and animals adapt to their environment, but
organisms are not mere passive responders to external influence;
equally important is the power of living things to change their
environment. On an everyday basis, biological communities
dramatically alter landscapes and microclimates and soils. On a
planetary scale, life transforms the Earth in ways that could
readily be detected from Mars. The best-known example is the
oxygenation of the atmosphere, brought about by the blooming of
photosynthetic bacteria about two billion years ago. Because of
these organisms' exhalations, a gas that had been present only in
traces came to make up a fifth of the atmosphere.
That living things shape their environment just as the environment
shapes them is not so hard to accept. That this two-way interaction
regulates the state of the planet in a way consistently favorable to
life is much harder to swallow—even setting aside all
questions of goals or intentions. The oxygenation of the atmosphere
offers a case in point. Was the change favorable to life? For most
of the organisms living at the start of that transition, oxygen was
a poisonous pollutant, and its sudden abundance either killed them
off or drove them underground. The new atmospheric chemistry seems a
great beneficence only from the point of view of us latter-day
obligate aerobes.
However implausible the "goal-seeking entity that regulates
itself on life's behalf," Lovelock does have one powerful
argument for the presence of some stablizing or moderating
influence: the mere continuity of life. Since the process of biology
got started on this planet, it has never been interrupted, not even
briefly, over a span that amounts to a fourth of the age of the
universe. We—and here I mean "we" in the broadest
sense possible—have withstood ice ages, cratering by comets or
asteroids, and vast volcanic eruptions that flooded continents with
lava and choked the atmosphere with sulfur. Even more remarkably (in
Lovelock's estimation), the temperature at the planet's surface has
remained within a range compatible with life even though the heat
output of the Sun has increased by more than 35 percent over the
history of the solar system. This long-term stability, Lovelock
argues, implies some kind of thermostat.
In the 1980s Lovelock and several colleagues described a computer
model called Daisyworld that suggested one possible mechanism of
thermostatic control. The model planet's surface is covered with two
kinds of flowers. Black daisies absorb more sunlight and are adapted
to a cooler environment; white daisies reflect heat and thrive in
warmer conditions. Shifts in the abundance of the two species tend
to automatically restore balance after any climatic perturbation.
For example, if more heat pours down upon the planet, the rising
temperature favors proliferation of the white daisies, which reflect
more sunlight and thereby ameliorate the heating. Of course
Daisyworld is merely a conceptual model; Lovelock does not imagine
that the Earth's temperature is really controlled by populations of
light and dark flowers, but he believes that subtler feedback loops
have the same effect.
Since Gaia theory is founded on notions of self-regulation and
stability, you might suppose that Lovelock would be a
skeptic—or at least not an alarmist—when it comes to the
global-warming controversy. On the contrary, The Revenge of
Gaia is an unrelenting Jeremiad about the damage done by human
excesses—especially the burning of fossil fuels—and
about the hellfire retribution that Gaia will soon visit upon us.
Returning to the Daisyworld model, Lovelock notes that homeostasis
fails if conditions ever stray outside the habitable range; and once
the flowers have wilted, they cannot be brought back to life.
"The temperature and chemical composition cease to be regulated
and the model system swiftly drops to the equilibrium state of the
dead planet."
This process is described not merely as the failure of an inanimate
controlling mechanism but as the illness or senescence of the
goddess Gaia. She is suffering from a "fever brought on by a
plague of people." Or perhaps Gaia is exasperated rather than
sick: "Like an old lady who has to share her house with a
growing and destructive group of teenagers, Gaia grows angry, and if
they do not mend their ways she will evict them."
Is there any hope of forestalling this disaster? Lovelock has
elaborate and specific prescriptions. (They take up nearly half the
book.) First and most important is to give up burning carbon and
shift the world economy to nuclear power. For long-distance
transportation, he suggests we scrap the jet airliner and build a
new generation of sailing ships. It's also crucial that we reduce
the area of cultivated land, and so we should start manufacturing
food from raw feedstocks or industrial by-products, with the
eventual aim of abandoning agriculture altogether. These are all
recommendations for the wealthy, industrialized nations. As for the
rest of the world, it's too late for sustainable development, he
says; the best we can manage is "sustainable retreat."
In his darker moods, he seems to think it's too late even for
sustainable surrender. "The prospects are grim," he
writes, "and even if we act successfully in amelioration, there
will still be hard times. . . . We are tough and it would take more
than the predicted climate catastrophe to eliminate all breeding
pairs of humans; what is at risk is civilization." In other
words, stock up on flashlight batteries, canned goods and ammo. In
the book's final vignette, "survivors gather for the journey to
the new Arctic centres of civilization." They will travel by
camel from one oasis to the next. Lovelock does not give a date for
this scenario, but I get the impression he believes it is decades
ahead, not centuries or millennia.
It's fair to say there's something for everyone in this
book—something each of us can admire and embrace, and also
something each of us can disdain or ridicule. For me it's pretty
nearly an even mix. Given the persistence of life on Earth, I'm
sympathetic to the idea that the global ecosystem must be reasonably
stable and self-correcting. But self-regulation requires no
purposeful, animating spirit; Lovelock's vision of Gaia twiddling
the controls to keep us comfortable—or else deliberately
turning up the heat to snuff us out—leaves me utterly baffled.
Even as metaphor it's nonsense. On the other side of the equation, I
share Lovelock's worry that climate change will make the world a
less congenial place for coming generations, yet I find his
predictions wildly overconfident. In his discussions of theory,
Lovelock puts much emphasis on the difficulty of understanding the
behavior of nonlinear systems with feedback loops; he even
exaggerates it a bit. And yet he does not hesitate to predict in
detail not only the effect of CO2 on climate but also the
response of ecosystems to climate change and even the consequences
for societies. It's his seeming certainty that makes me most
skeptical. But then what do I know? Lovelock has a goddess
whispering in his ear.