Mark Lynas
The Nine Planetary Boundaries
The Quantified Planet
“About 74,000 years ago,” Lynas began, “a volcanic event nearly wiped out humanity. We were down to just a thousand or so embattled breeding pairs. We’ve made a bit of a comeback since then. We’re over seven billion strong. In half a million years we’ve gone from prodding anthills with sticks to building a worldwide digital communications network. Well done! But... there’s a small problem. In doing this we’ve had to capture between a quarter and a third of the entire photosynthetic production of the planet. We’ve raised the temperature of the Earth system, reduced the alkalinity of the oceans, altered the chemistry of the atmosphere, changed the reflectivity of the planet, hugely affected the distribution of freshwater, and killed off many of the species that share the planet with us. Welcome to the Anthropocene, our very uniquely human geological era.”
Some of those global alterations made by humans may be approaching tipping points---thresholds---that could destabilize the whole Earth system. Drawing on a landmark paper in Nature in 2009 (“A Safe Operating Space for Humanity,” by Johan Rockström et al.) Lynas outlined the nine boundaries we should stay within, starting with three we’ve already crossed. 1. Loss of biodiversity reduces every form of ecological resilience. The boundary is 10 species going extinct per million per year. Currently we lose over 100 species per million per year. 2. Global warming is the most overwhelming boundary. Long-term stability requires 350 parts per million (ppm) of carbon dioxide in the atmosphere; we’re currently at 391 ppm and rising fast. “The entire human economy must become carbon neutral by 2050 and carbon negative thereafter.” 3. Nitrogen pollution. With the invention a century ago of the Haber-Bosch process for creating nitrogen fertilizer, we doubled the terrestrial nitrogen cycle. We need to reduce the amount of atmospheric nitrogen we fix per year to 35 million tons; we’re currently at 121 million tons.
Other quantifiable boundaries have yet to be exceeded, but we’re close. 4. Land use. Every bit of natural landscape lost threatens ecosystem services like clean water and air and atmospheric carbon balance. “Already 85% of the Earth’s ice-free land is fragmented or substantially affected by human activity.” The danger point is 15% of land being used for row crops; we’re currently at 12%. 5. Fresh water scarcity. Increasing droughts from global warming will make the problem ever worse. In the world’s rivers, “the blue arteries of the living planet,” there are 800,000 dams with two new large ones built every day. The numeric limit is thought to be 4,000 cubic kilometers of runoff water consumed per year; the current number is 2,600. 6. Ocean acidification from excess atmospheric carbon dioxide is increasingly lethal to ocean life such as coral reefs. The measure here is “aragonite saturation level.” Before the industrial revolution it was 3.44; the limit is 2.75; we’re already down to 2.90. 7. The ozone layer protects the Earth from ultraviolet radiation. One man (Thomas Midgley) invented the chlorofluorocarbon coolant that rapidly reduced stratospheric ozone, and one remarkable agreement (Montreal Protocol, 1987) cut back on CFCs and began restoring the ozone layer. (In Dobson units the limit is 276; before Midgley it was 290; we’re now back up to 283.)
Two boundaries are so far unquantifiable. 8. Chemical pollution. Rachel Carson was right. Human toxics are showing up everywhere and causing harm. Coal-fired power plants are one of the worst offenders in this category. (Lynas added that nuclear waste belongs in this category but “the supposedly unsolved problem of nuclear waste hasn’t so far harmed a single living thing.” 9. Atmospheric aerosols---airborne dust and smoke. It kills hundreds of thousands of people annually, the soot causes ice to melt faster, and everyone wants to get rid of it. But one beneficial effect it has is cooling, so Lynas proposes “we could move this pollution from the troposphere where people have to breathe it up to the stratosphere where it can still cool the Earth and no one has to breathe it. That’s called geoengineering.”
Lynas proposed that the goal for the future should be to get the whole world out of poverty by 2050 while staying within the planetary boundaries. Among the solutions he proposed are: clean cookstoves for the poor (they cause 1.6 million deaths a year); better GM crops for nitrogen efficiency and concentrated land use; integral fast reactors which run on nuclear waste (a recent calculation shows the UK could get 500 years of clean energy from its present waste, and the resulting IFR waste is a problem for 300 years, not for thousands of years); international treaties, which are crucial for dealing with global problems; carbon capture (everything from clean coal to biochar); and ongoing “dematerialization,” doing ever more with ever less, including more intense farming on less land. “Peak consumption,” Lynas noted, has already arrived in much of the developed world.
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primer
Journalist and environmentalist Mark Lynas has a knack for getting deep down into the crux of problems and scraping out the science. Though we shouldn’t ever mistake a clear view for a short distance, this knack is making the terrain between us and a sustainable, thriving biosphere look pretty navigable. Much of his writing has focused on finding ways to objectively measure, at personal and global scale, our relationship with the environment.
He may be best known for his book Six Degrees: Our Future on a Hotter Planet, in which he explores the ecological changes humanity can expect if Earth’s average temperature rises as much as the IPCC predicts it might over the next century.
In his most recent book, The God Species: How the Planet Can Survive the Age of Humans, he places climate change within the context of the nine planetary boundaries, a fairly new ecological framework for assessing the health of our biosphere. Much as we are able to identify and assess the nervous system as distinct from (but intertwined with) the circulatory system, the digestive system, the endocrine system, etcetera, we’re beginning to better understand the distinctions and interrelations between our planet’s climate, oceans, geology, and biodiversity. Scientists have identified nine of these systems and boundaries beyond which they begin destabilizing each other, leading to a biosphere that can no longer support a global human civilization.
Lynas served for two years as climate science advisor to the (now deposed) president of the Maldives, a low-lying island nation that was taking climate change seriously enough to have explicitly set the goal of becoming carbon neutral by 02020. (The archipelago hasn’t got any land more than 6 feet above sea level, so climate change and rising waters represent a rather immediate existential threat to them.) Now that president Nasheed has been removed via coup, however, it’s unclear how devoted the government will remain to that goal. While there, though, Lynas helped them asses and make partnerships around alternative energy and other emissions-reducing technologies.
As we’re coming to terms with the Anthropocene, a good understanding of our actions’ impacts is vital. Mark Lynas has been following the scientists working to develop that understanding and his Seminar will offer a distillation of how we can track the biosphere’s health.