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.
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 NiÒos and La NiÒas, 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:
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:
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’vesaid before, our human nature is not to do what we can, but rather to do what we must.