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Greenhouse Warming: Prepare for the Worst

David Holt: Coastal Watcher, 1963; from Modernism and Memory: Rhoda Pritzker and the Art of Collecting, the catalog of a recent exhibition at the Yale Center for British Art, edited by Ian Collins and Eleanor Hughes and published by Yale University Press
Yale Center for British Art, New Haven
David Holt: Coastal Watcher, 1963; from Modernism and Memory: Rhoda Pritzker and the Art of Collecting, the catalog of a recent exhibition at the Yale Center for British Art, edited by Ian Collins and Eleanor Hughes and published by Yale University Press

As the December 2015 United Nations climate conference came to a close in Paris, representatives from all 195 of the world’s sovereign states applauded their achievement: a global plan intended to slow the growth of greenhouse gas emissions. The representatives cheered, their presidents declared victory, and the world’s pundits split predictably about what had been done. Some thought the agreement was a step toward saving the planet; others thought it a document too weak to achieve its goals.

The “Paris Agreement under the United Nations Framework Convention on Climate Change” is the product of years of negotiation following a widely panned 2009 conference in Copenhagen. It recognizes “that climate change represents an urgent and potentially irreversible threat to human societies and the planet.” Its objective is to put the world onto a path “consistent with holding the increase in the global average temperature to well below 2°C above pre-industrial levels” beginning in 2020, while also “pursuing efforts” to limit the increase to an even lower maximum limit of 1.5°C.

Creating international agreement on this language is a major achievement. But although it has been seen as a turning point, the Paris Agreement represents the easy part of reining in climate change. The harder challenge lies ahead. For reasons of consensus more than science, a globally averaged temperature increase of 2°C has emerged as an acceptable upper limit among policymakers seeking to curb emissions growth. A flaw of the Paris Agreement, as even its ardent supporters concede, is that it relies upon the voluntary pledges of sovereign states that do not currently add up to anything close to a +2°C temperature limit (let alone a +1.5°C limit) at present. Instead, the current commitments place our planet on a path of continued warming, perhaps to as much as 3.5°C, roughly double the agreement’s stated objectives. Its success also implicitly relies on emerging technologies, like carbon capture and storage (CCS), which takes excess carbon dioxide from the atmosphere and deposits it underground. These technologies have yet to be developed on a large scale.

While the limits on change in temperature I’ve cited and the differences between them may seem small, they actually represent enormous shifts in the earth’s climate. A 2.5°C change is huge, equivalent to the difference between the average daily temperatures of New York City’s hottest and coldest years on record. Already, the global average temperature has risen nearly 1°C above preindustrial levels, and the change has been scientifically linked to unprecedented consequences of that warming. These include heat waves, fires, ice melt, coral reef die-offs, and animal migrations to higher latitudes and elevations. A 3.5°C change would be almost as large as the contrast in temperatures between today and the last ice age, when global temperatures were about 5°C cooler on average. Those five degrees buried much of North America and Europe in glacial ice and sank the global sea level some 330 feet lower than it is today. There were different ecosystems on land and in the oceans, and the shape of the world’s coasts was radically different than it is now.

Further, the concept of globally averaged temperature change, while a useful benchmark for policy, is misleading. Large areas of the planet will experience smaller temperature increases than the average (mainly over the open ocean), and others greater increases (especially over land, in northern latitudes, and in the tropics). The Arctic is currently warming at a pace more than double the global average, with startling reductions in the amount of sea ice, disintegration of floating ice shelves, and rising waters from the melting of ice sheets and glaciers.

The runoff of melted ice from continents to oceans, together with the expansion of seawater as it warms, is now driving up sea levels by more than 3.4 millimeters per year on average. Like air temperatures, sea levels are rising slower than average in some areas and faster than average in others. In light of such trends, critics of the Paris Agreement—while giving due praise for the diplomacy that achieved it—assert that its only real chance for success rests upon the agreement’s requirement to revisit the pledged commitments every five years, which they hope will result in their being ratcheted upward in future years. The agreement thus offers hope, but not a guarantee of action.

Anticipating such developments while writing before the conference, Tim Flannery has published Atmosphere of Hope, his second major book on climate change and a timely follow-up to The Weather Makers, his best seller from over a decade ago. Like other books on this subject, Flannery’s tries to raise concern about the dangers of inaction on climate, while also trying to avoid the suggestion of a lost cause.

He starts the reader off with a set of chapters that survey some of the recent disturbing scientific discoveries of the detrimental impacts of climate change. These include observed shifts in temperature extremes, record heatwaves in Australia, Europe, and Russia, ferocious wildfires in Australia, Canada, and Spain, and public health problems caused by climate change including diseases, airborne particulates, and hay fever. Changes in the movement of water above and below the earth’s surface have resulted in larger droughts and floods, and declines in water supplies from disappearing snowpacks and glaciers.

Flannery pays special attention to the problem of increased acidity of the ocean. This is a consequence of rising CO2 levels in the atmosphere that can be modeled with more certainty than can temperature increases. One study even warns of a decline in the quality of wheat and rice crops if carbon dioxide concentrations in the atmosphere exceed 0.055 percent. The level is currently around 0.040 percent, up over 40 percent from its preindustrial level. This is mainly due to the burning of fossil fuels and the manufacture of cement.

Burning fossil fuels and making cement are important parts of what modern, industrialized societies do. However, two premises of Flannery’s book are that putting a price on carbon does not harm economies, and that our industrial-era reliance on traditional energy sources—coal, oil, uranium, and even natural gas—is drawing to an end.

These assertions are largely uncontroversial among all but a very small minority of qualified experts (although not among American politicians and energy companies). They are consistent with trends already evident in much of the world for coal and nuclear power. Coal consumption has decreased in the United States because of cheap shale gas and is leveling off in China. Public support for nuclear power has eroded in countries like Germany and Japan following the 2011 Fukushima disaster. With their high cost of construction (around $15 billion) and long amortization periods, nuclear power plants now seem overpriced, even if their environmental risks could somehow be overlooked.

Less evident is the end of conventional oil and gas use; or use of unconventional fossil fuels like shale, or “tight” oil (loosened by hydraulic fracturing, or “fracking”), and Canada’s vast bitumen sands (called “oil sands” or “tar sands”—Flannery uses the latter term). But to Flannery, low oil prices, which in turn discourage development of both unconventional and hard-to-access reserves, like those in the Arctic, reflect a deeper and probably permanent trend:

There is another side to the oil price story, which relates to innovation and the demand for oil. One obvious influence on demand is the slowing of the Chinese economy. But I think that thousands of seemingly small initiatives, which are often overlooked, are also having an impact. From innovative financing that encourages building retrofits that reduce bills for heating fuel, to lighter building materials for transport vehicles that reduces fuel consumption, and on to the hybridisation and electrification of transport, investments are reducing demand for oil products.

A potential weak spot in Flannery’s analysis is his assumption that some companies will willingly give up much of their carbon as “unburnable” or stranded. To have a three-in-four chance of limiting global climate warming to 2°C, we can’t emit more than 600 gigatons—i.e., 600 billion tons—of CO2 between now and 2050. However, burning all fossil fuel reserves that have been appraised by energy companies would release approximately 3,000 gigatons of CO2. Thus, stabilizing climate within the 2°C limit will require leaving some 80 percent of currently known and appraised reserves in the ground.

If we are truly serious about stabilizing the earth’s climate, this implies that most state and private energy companies are fundamentally overvalued, because not all of their assets can be used. If climate change is to be controlled, the enormous coal reserves of China, Russia, and the United States would have to be abandoned, along with natural gas reserves of the Middle East, nearly three quarters of Canada’s bitumen sands, and the quest for offshore oil in the Arctic. There is little indication yet that such abandonment will take place, yet Flannery holds high hopes for a global divestment movement and an eventual “orderly process of asset devaluation” taking account of unburnable carbon. He doesn’t say how this process will be put into action. What political developments, for example, will bring to an end the extraction of oil from Canada’s sand fields?

The book brightens as it turns to renewable solar and wind energy, both because they are carbon-neutral and because fast-moving sectors have exciting business opportunities. Costs for these new energies have plummeted (especially solar energy); as a result the business of generating and distributing electricity through power grids has changed, and new installations for wind and solar electricity generation are exceeding the headiest growth projections of even a few years ago. The International Energy Agency now projects that solar photovoltaic systems (which convert sunlight directly into electricity) and concentrating solar power systems (which convert sunlight into the heat needed to run a generator) could together generate nearly 30 percent of the world’s electricity by 2050 while reducing global emissions by some six gigatons of CO2 per year. While not in itself sufficient to halt climate change (we currently emit around thirty-six gigatons per year), the transition is encouraging and a crucial condition for the success of the Paris Agreement.

The rising use of electric passenger vehicles is another promising recent development, both because they represent new sources of renewable power and because flexible battery storage can help reduce a major problem inherent in unpredictable wind and solar energy sources: that the power they generate is variable and intermittent. Plugging parked electric vehicles into buildings or power grids allows their batteries to discharge to those grids during hours of peak electricity demand and draw from them during off-peak times. Even a hundred electric vehicles in a parking lot could supply sufficient energy for a 150,000-square-foot office building during peak hours.

Flannery observes that a chief obstacle to broader consumer adoption of such vehicles is their high battery cost, but this too is falling fast. By 2020 a breakthrough may come from Nevada, where Tesla is building the largest factory in America in order to manufacture a half-million electric car batteries per year. Should the venture succeed, it will make electric vehicles cost-competitive with gasoline cars. The environmental benefits of a fully electrified vehicle fleet would be great. Exhaust and smog would disappear from the world’s cities, a new electricity market would grow, and flexible energy storage to combat the coming heat waves and power shortages would be possible.

Under no reasonable projection can all fossil fuel use be eliminated in the near future. Flannery thus introduces the reader to some commonly proposed “geoengineering” options, including technologies with the potential to reflect sunlight back to space; to draw down atmospheric carbon dioxide through biogeochemical or chemical means; or to capture and bury carbon directly from the waste stream of fossil fuel power plants. All are technologically new and pose risks, and they have yet to be shown to work on a large scale. One of the oldest ideas is to brighten the planet’s reflectivity, or albedo, by shooting sulfate aerosols—fine, solid particles—into the stratosphere. But this could alter global rainfall patterns in unpredictable ways, as the interaction of sulfates and cloud formation is not well understood.

Flannery’s analysis leans on a comprehensive National Research Council (NRC) review of geoengineering research, a report concluding that none of the geoengineering proposals could be effective enough to substitute for reductions in emissions. Nonetheless, he curiously singles out a (relatively) mild set of geoengineering ideas that he calls “third-way” technologies, many of which rely on “biogeochemical sequestration policies.” Most are in early stages of development and do not require aggressive manipulation of the planet. Instead, they seek to amplify natural biogeochemical processes:

Third-way technologies recreate, enhance, or restore the processes that created the balance of greenhouse gases which existed prior to human interference, with the aim of drawing carbon, at scale, out of Earth’s atmosphere and/or oceans.

Papua New Guineans gathering seaweed for income in the Cartaret Islands, where rising sea levels are destroying their crops and drinking water, May 2013
Kadir van Lohuizen/Noor/Redux
Papua New Guineans gathering seaweed for income in the Cartaret Islands, where rising sea levels are destroying their crops and drinking water, May 2013

The idea here is to borrow from earth’s natural biogeochemical processes, but boost them with a helping human hand. Some of the examples Flannery describes include expanding the earth’s forest cover, fertilizing its oceans, accelerating rock weathering, burying charcoal, creating seaweed farms, and making carbon-neutral plastics and cement. Among the more radical ideas is developing laboratory-based photosynthesis reactions in order to manufacture synthetic oils. Doing so would store excess solar energy in the form of chemical bonds. The outcome would be, in effect, the storage of the sun’s heat.

Flannery’s fascination with these technologies appears to derive from the NRC report and his experience as a judge—together with Sir Richard Branson, Al Gore, James Hansen, James Lovelock, and Sir Crispin Tickell—for Branson’s Virgin Earth Challenge. This contest offered a £25 million prize for a commercially workable strategy to remove greenhouse gases from the atmosphere. Some 10,000 ideas were submitted, of which the panel selected eleven (all involving “third-way” sequestration) for further study.

Flannery is not afraid to veer off into the fringe. He describes at length a plan to cover 9 percent of the oceans in seaweed farms, and an offbeat proposal to bury carbon dioxide as dry ice inside the Antarctic ice sheet. This makes for lively, imaginative reading, but granting outsized page space to little-cited studies of this kind actually undermines his argument that “third-way” technologies will be important. One must hunt hard among the potpourri of case studies and anecdotes in Atmosphere of Hope to find Flannery’s vision of how they might actually converge to make meaningful impact:

Forestry and soil carbon might together sequester a gigaton of carbon per year, and biochar a similar amount. Direct air capture and silicate rocks might capture another gigaton between them, and carbon-negative cement and carbon-negative plastics another gigaton. That’s four gigatons of carbon per year, or around fifteen gigatons of CO2.

Flannery concedes that this number is optimistic (none of the technologies invoked has been demonstrated on a large scale); and that even fifteen gigatons of CO2 would barely draw down atmospheric levels by 0.0001 percent per year. As such, his call to elevate research and development of third-way strategies offers no more than a partial solution to the climate crisis. But this is characteristic of all the measures proposed to stabilize temperature, as elegantly shown by Princeton’s Stephen Pacala and Robert Socolow, who introduced the concept of “stabilization wedges” in 2004.* Each stabilization wedge—a doubling of car fuel efficiency, a tripling of nuclear power generation, a tenfold increase in wind power generation, elimination of tropical deforestation, and eleven other possible approaches to climate change—represents a partial solution. Collectively they could reduce global carbon dioxide emissions by at least fifteen gigatons per year by 2060. No single strategy is in itself sufficient to solve the problem.

Assembling this sort of budget is critical for third-way technologies or any other strategy to gain traction. In a speech made before the Paris climate conference, French President François Hollande told the negotiators that “history is written by those who commit, and not those who calculate.” But in the case of greenhouse gases, that statement is not true. Despite the cheers in Paris, there remains no binding path to hold the world to a 2°C warming limit—or indeed any limit. Flannery recognizes this, and sees that climate change is not simply a transition from an old standard state to a new one. Instead it is an ongoing, unfolding process requiring vigilant attention and adaptation along the way.

To preserve anything resembling the earth’s preindustrial climate will require retooling of how we obtain, price, distribute, and use energy. This, in turn, threatens the continuation of some sectors such as coal mining and enhances opportunities for others, such as smart grids. With such stakes, acrimony and political conflict are inevitable. Amid the claims of paid climate denialists and paid green-lobby enthusiasts, the average citizen is left bewildered about what is settled science and what is not. The standard journalistic practice of reporting “both sides” of a contested issue lends outsized emphasis to minority views, doing little to clarify the matter.

Many are surprised to learn that the science of greenhouse warming is uncontroversial, and has been known more or less since the 1820s, when the French mathematician Joseph Fourier observed that the earth’s surface was too hot given its distance from the sun. Today, some 97 percent of climate scientists—a skeptical, irascible, competitive bunch who are trained to disagree with each other—agree that climate change caused by human activities is underway. Ironically, the most common counterarguments flung against them—evidence of nonanthropogenic climate variations in the geological past—were also discovered by these same scientists.

Flannery is outspoken about where he stands:

Public ignorance has given the politicians the space to continue to fight last decade’s battles, instead of addressing today’s most urgent issue. The old and tired arguments of the sceptics, which have hardly changed in decades, ignore both scientific facts and lived experience.

And, when the science becomes irrefutable:

Over the years they’ve gone from denying that climate change exists, to arguing that it isn’t caused by humans, to saying that even if it is, it’s too costly to fix.

Atmosphere of Hope persuades more than ever that technological advances can help, but not solve, the climate crisis. Just as we all know we should eat less and exercise more, the unpopular solutions remain the most crucial. First, the world needs companies and entrepreneurs to commit to more efficient, frugal methods of fossil fuel use. Second, governments must levy big carbon taxes to encourage companies to develop the diverse energy alternatives currently available, and to help fund research and development for new ones. Finally, we must prepare for the worst by building strategies for adaptation, such as coastal defenses, even as we hope to lessen the blows with new technologies such as those presented in Atmosphere of Hope.

  1. *

    See Stephen Pacala and Robert Socolow, “Stabilization Wedges: Solving the Climate Problem for the Next 50 Years with Current Technologies,” Science, Vol. 305, No. 5686 (August 13, 2004).