frog conjugation: Why we need to leave wiggle room for the planet

Bob Holmes, consultant

In The Human Quest scientist Johan Rockstrom and photographer Mattias Klum make a compelling case for why we need to stay within environmental boundaries

DOZENS, if not hundreds, of books describe the world's environmental crisis and offer prescriptions for a more sustainable future. But only one begins with forewords by former US president Bill Clinton and former Norwegian prime minister and UN sustainability chief Gro Brundtland, as well as other environmental luminaries.

In The Human Quest, Johan Rockstr?m and Mattias Klum deliver a show worthy of this fanfare. Over the past three decades, they argue, our activity has pinned the Earth in a triple squeeze of growing human population, changing climate and failing ecosystems. Of course, environmental Cassandras have been saying that for many years, but Rockstr?m and Klum add a fourth, urgent squeeze. Earth's history is full of tipping points where climates and ecosystems change suddenly, dramatically, and in surprising ways - think ice ages and, at the other extreme, a hothouse Earth with forested poles. Such changes would be catastrophic for human society.

If we want to avoid that risk, they say, we must keep well clear of the tipping points at the limits to growth. That's a radical statement: it is not good enough to keep within the boundaries the planet sets for the human enterprise - we have to leave a buffer zone, too, for safety's sake.

Three years ago in the journal Nature, Rockstr?m, director of the Stockholm Resilience Centre in Sweden, and his colleagues, identified nine of these planetary boundaries, which together define a "safe operating space" for humanity. Here he teams up with photographer Klum to bring this powerful notion to the public.

Successive chapters outline the three big boundaries with catastrophic tipping points - climate change, stratospheric ozone depletion and ocean acidification; the four "slow" boundaries that underlie Earth's ability to buffer insults and resist change - biodiversity loss, fresh-water use, land use and nutrient cycling; and two human-made boundaries - chemical pollution and particulate air pollution. For some, notably climate change, biodiversity loss and nitrogen overload, we have already passed the limits deemed safe. For others, such as water and land use, we still have a little breathing room.

But our goal for all nine, they argue, must be ultimately to steer society back safely within the limits. We have already done that for one of the boundaries, with the Montreal protocol that restricted ozone-depleting chemicals. Reversing the other eight will require a huge shift in our outlook on the world - a shift comparable, they say, to the Enlightenment that brought us into the age of reason just a few centuries ago. That, of course, is the human quest of the title and, like any quest, it won't be easy.

Rockstr?m and Klum offer a few specific suggestions: switch immediately to renewable energy and sustainable agricultural practices, include environmental costs in economic calculations, and so on. But the real task, they argue, is a shift in mindset. If we can manage that, human creativity will take care of the details.

They make a persuasive case, and their plea gains emotional impact from Klum's spectacular photographs. The e-book also includes video clips that add extra richness, though it can be difficult to view full pages clearly designed for print. On my iPad, at least, there seemed no way to do so without rendering the type too minuscule to read easily.

Unfortunately, the print book is currently only available in Swedish. That's a shame because it may be worth having a copy in real, physical form on your shelf - where it can serve as an ongoing reminder of the task ahead.