Nature

Books: more nasty surprises ahead

Coral reefs could be the first entire ecosystem to be wiped out, Peter Sale writes in Our Dying Planet. Jan McGirk found his arguments about our less resilient, less reparable world persuasive.
English

Our Dying Planet: An Ecologist’s View of the Crisis We Face
Peter F Sale
University of California Press, 2011

Peter F Sale’s Our Dying Planet: An Ecologist’s View of the Crisis We Face, could carry off an even blunter subtitle over its ghostly cover photo of blanched coral spikes: “It’s later than you think.”  At the present rate of decline, the author predicts, living coral reefs may no longer exist by the time our grandchildren reach maturity, before the end of this century. “We’ve wiped out a lot of species over the years. This will be the first time we’ve actually eliminated an entire ecosystem,” he laments.

Sale
, an eminent marine ecologist who now works as assistant director of the Institute for Water, Environment and Health (IWEH) at the United Nations University (UNU), has been praised for writing a powerful statement on the future of life on earth. Yet, since his book was published last September, the persuasive evidence he presents on environmental deterioration and the radical fixes he proposes have not heightened concerns much beyond academia. 

What difference will it make for mankind if coral reefs go extinct? Biodiversity would be diminished. While living coral reefs, the massed exoskeletons formed by colonies of tiny spineless marine creatures, comprise only a scant 0.1% of the ocean’s vast sea floor, they support 25% of all marine species.  Counting the different types of sea creatures per hectare, that’s even more diversity than in a typical rain forest. 

Potential pharmaceutical uses for coral-reef products are just as promising as medicines derived from exotic jungle plants and animals. Already they range from powerful sun blocks to leukemia-fighting drugs. What’s more, coral-reef systems directly provide food or jobs for an estimated 275 million people living on islands or along coastlines. They also help protect vulnerable shores from wave erosion and stormy seas.

The 19th-century naturalist Charles Darwin marvelled at the diversity of life teeming within Australia’s Great Barrier Reef, though the 18th-century explorer James Cook cursed the reef after he ran his ship Endeavour aground. Much more recently, since the 1950s, ecologists have analysed reefs extensively because coral is a sensitive bellwether, like “a canary in an environmental coalmine”, and acts as an early-warning system for imbalances in the sea and the atmosphere. Ecologists did not observe mass coral bleaching and die-offs before 1979, but since then, about one fifth of the planet’s reefs have been destroyed.

Worryingly, climatologists have measured an increase of 0.67° Celsius in sea-surface temperatures.  (Global records started back in 1880). When temperatures rise, tiny coral polyps undergo thermal stress and expel the algae on which these reef-builders co-depend. After a few weeks without algae, bleached-out corals die. Sale notes dryly that post-millennial coral losses may appear to be less dramatic than the “conspicuous and extensive” mass bleaching of 1998 “simply because there is less coral around”. He acknowledges that fossil evidence has shown “multimillion-year pauses” when reefs appeared to be absent, and that — under ideal circumstances — some coral polyps might recover enough during a prolonged hiatus that reefs could eventually re-emerge.

Admittedly, that’s a big “if”, given the effects of greenhouse gases, which Sale reminds us have been “consistently underestimated by the Intergovernmental Panel on Climate Change” (IPPC). Carbon-dioxide (CO2) concentration currently is estimated at about 390 parts per million (ppm) in the atmosphere, but most climate experts predict that it will soon exceed 500 ppm. Sale suggests that if atmospheric CO2 concentration can be kept under 450 ppm, coral reefs might still be preserved in some form.

When 250 million years’ worth of stored carbon is released into the atmosphere during just 150 years, the impact is measurable. Nearly one-third of the carbon dioxide spewed into the air gets absorbed by the ocean, turning saltwater increasingly acidic, especially in relatively shallow reef areas.

Because media reports about dying reefs or drowned polar bears often are oversimplified, Sale points out, detractors like to dismiss them as alarmist. “The sad reality is that the damage we have already done is unlikely to be undone before some of these particularly susceptible species disappear,” he observes.  Meanwhile, critical issues such as local overfishing, ocean acidification, the introduction of alien species and the overdevelopment of coastal property tend to be under-reported, perhaps deemed too humdrum to be newsworthy. That does not lessen their impact. 

As long as unlimited growth is promoted on a planet with finite resources, the earth’s interactive systems cannot remain in balance. Yet scaling back consumerism remains a low priority for most of the general public, Sale observes. He reminds readers that humans presently exploit basic resources at an unsustainable rate that is 40% more than the planet’s annual production of these necessities, even though the global population is expected to reach 9.2 billion by mid-century.  

Piecemeal strategies to lessen environmental damage tend to make it seem less critical, Sale argues, urging scientists and policy-makers to consider the whole spectrum of linked problems. There is no single cause for this damage, but one single agent: humans. Existing technologies can increase energy efficiency in the face of more severe weather, droughts and famine linked to climate change, Sale reassures us. But, he warns, “there are going to be more nasty surprises, because the climate system is complex and multi-faceted. We are still learning to understand it.”

No one denies that the ideologically charged debate over manmade climate change is heating up. While green activists despair over shouting matches with obstinate “climate-change deniers”, a prominent American blogger, Matt Drudge, and media mogul Rupert Murdoch’s Wall Street Journal like to pit pragmatic “climate sceptics” against “global warming hucksters”. Consider a recent opinion piece in The Wall Street Journal, headlined “No Need to Panic About Global Warming”. There’s no compelling scientific argument for drastic action to “decarbonize” the world’s economy, the article declared, over the signatures of 16 scientists — none of them climatologists. Hundreds of rebuttals and recriminations ensued, but few opinions seem to be altered by the heated exchange. 

Sale, a Canadian academic, believes responsible debate leads to effective policy and largely manages to keep above the fray. He considers potential solutions from a range of perspectives and warns against cherry-picking facts to support a favoured hypothesis. But he doesn’t shy away from presenting new controversies. For instance, Sale recommends switching to micro-nuclear power plants in order to speed up the transition from fossil fuels to alternate energy sources. He promotes the extensive use of solar power in the design or retrofitting of houses and highways. To scale back burgeoning food and energy demands, Sale encourages an informal one-child-per-family policy in developed countries, allowing tax deductions only for the first child.

The author contends that our world is proving to be far less resilient and reparable than scientists had previously assumed, and points to an exponential increase in the rate of extinction. Time is running out. Our Dying Planet is not a specialist text, but targeted at a wider readership. Sale’s aim is “to convey the complexity and severity of the environmental crisis, and the need for quick and determined action if we care at all about our own children. There is still time to act, and economically viable paths to take, that will bring us to … a future in which humans live rich and fulfilling lives as stewards of an ecologically sustainable Earth.”

Jan McGirk is a former correspondent for
The Independent (London) who has reported on environmental issues and disasters in Asia, Latin America and the Middle East.