Can We Get to Zero?

Landscape architecture can mitigate carbon emissions, but it is also implicated among the causes.

By Steven Austin, ASLA 

The Paris Agreement on climate change, created by the consensus of 197 nations, went into effect in November 2016 and has enormous implications for the practice of landscape architecture. If adhered to by its signatories, the agreement signals the end of the fossil fuel era by midcentury, well within the life spans of many landscape architects currently practicing. Though it may seem wonderfully “green,” this energy transition poses profound questions for the practice of landscape architecture at a time when the discipline is needed more than ever.

The Paris Agreement foretells a civilization powered nearly exclusively by renewably generated electricity, not fossil-fueled fire, like today. This will impose severe limits on landscape architecture’s materials, construction methods, and professional mobility. The agreement also portends a society with much less energy overall, as fossil fuels currently make up more than 80 percent of total energy consumed and cannot be easily replaced. These stark realities will challenge landscape architects to adapt to the impending zero-carbon future.

Last year set the record for the hottest year in measured history, breaking 2015’s record, which itself
broke 2014’s. The earth is rapidly warming owing to the use of fossil fuels, which spew huge amounts of carbon dioxide (CO2) into the atmosphere. Annual global mean surface temperatures are already close to 1 degree Celsius higher than preindustrial levels. Ominously, average temperatures in some months of 2016 were more than 1.5 degrees Celsius above preindustrial levels. This means the planet is now approaching the upper range of temperatures that have existed for the past 10,000 years. That stable climatic period, the Holocene, coincides with the development of human civilization. If humans continue to heat the planet, civilization will be moved outside of its known safe operating space.

To avoid this scenario, the Paris Agreement seeks to hold global warming to no more than 2 degrees Celsius above preindustrial levels—and to pursue efforts toward a more ambitious limit of 1.5 degrees Celsius. Alas, the climate is already near that threshold. If anthropogenic warming continues at this rate, the global temperature could increase by as much as 4 degrees Celsius within this century. This would result in a climate that has not existed on earth for millions of years, far longer than the 200,000 or so years that modern humans have been around.

A recent report by the Intergovernmental Panel on Climate Change found that the last time the earth was that warm, about 125,000 years ago, sea levels were 15 to 30 feet higher than today. That amount of sea-level rise now would lead to a radical reshaping of the earth’s coastlines, affecting hundreds of millions of people and all of the global economy, over a ridiculously short time frame. With an increase of 2 degrees Celsius, global farming would also be dramatically affected by either too much or too little water and destructive storms.

The incredible impacts associated with this heating would likely disrupt the lives of hundreds of millions, perhaps billions, of people, potentially leading to severe and perpetual conflicts.

It must not get to that point. The Paris Agreement plots a path to ensure that it doesn’t. As a first step, the world economy must cease annual increases of CO2 pollution. This has occurred over each of the past three years, possibly attributable to energy efficiencies, increases in renewable energy, and the retirement of many coal-fired power plants. The next step, however, is more difficult: getting annual CO2 production to near zero within the next 30 years. This is the largest challenge, because the industrial economy measures growth by increasing, not decreasing, CO2 emissions every year. The final step will require simultaneously offsetting all small but unavoidable CO2 emissions to achieve a net balance of zero carbon emissions. Doing all this, right now, will result in a two-thirds chance of limiting temperature increase to no more than 1.5 degrees Celsius. Those are humanity’s best odds.

How will our enormous civilization and economies be powered, if not with fossil fuels? The answer: renewably generated electricity. This has two implications for landscape architecture. First, within our lifetimes, there will likely be significantly less energy to use than today. And it means the end of most carbon-fueled fire, upon which much of current landscape architecture practice depends. These implications will fundamentally change landscape architecture.

A world without fossil fuels will be an all-electric one. Renewable energy technologies, such as solar panels and windmills, produce electricity. Fortunately, much of the world is already wired for electricity. However, it is a mistake to assume that all that is needed is to swap fossil fuel-powered energy generators with renewable ones. It is not a matter of simply unplugging dirty energy and replacing it with “green” renewables.

The first problem confronting us is the sheer scale of the energy that needs to be replaced. Today, only about 10 percent of the United States’s energy comes from renewables. Nuclear power provides about 9 percent of the energy in the United States, but this means that 80 percent of our energy is derived from fossil fuels. This is the scale of the problem: transforming renewables from 10 percent of our energy use to at least 90 percent. This is a staggering task, yet one that will need to be done within 30 years to meet the agreement’s goals.

Unsurprisingly, there are no real-world simulations as to how this will be possible. Still, the need to quit fossil fuels is growing every year. Therefore and soon, while fossil fuels are being phased out, there may not be any near-term—and possibly not even long-term—replacement of that lost energy.

Renewably powered energy has some known limits. Intermittency is obvious: The sun doesn’t always shine nor does the wind always blow. That leads to the second limit: storage. There are currently no industrial-scale technologies that can store large amounts of renewable energy. The third limit springs from the first two. The existing electric grid is a centralized system, sending out energy as it is needed to where it is needed, whereas renewable energy sources are scattered and intermittent. All this indicates that meeting current energy demand with renewables will require extensive, and expensive, system redesign.

Other issues remain unresolved. To generate anything near current energy consumption, an all-renewable future will require enormous spatial footprints of solar and wind factories. Although the switch to renewables may be ultimately positive, there will likely be serious economic, environmental, and social ramifications with these fixtures sprawling across the earth and seas.

Then again, visions of large-scale renewable energy factories may be a mirage. There is no proof that the mining, transport, and transformation of raw materials into renewable energy collectors, nor their installation, can be done without fossil fuel inputs. It is not idle speculation to ponder if an industrial-sized windmill can be used to generate all the energy needed to make another industrial-sized windmill from scratch.

So, while it is not possible to estimate exactly how much energy will be available in an all-renewable future, it will likely be significantly less than we have been accustomed to. Limited energy availability, and the resulting high cost, will pose ethical questions for landscape architecture practitioners: For what projects, and for whose benefit, shall we use that limited energy?

Energy limits are one side of the transition. The other side reveals the energy substitution challenges landscape architects face. Renewable energy simply cannot do all of the things that fossil fuels can. Right now, carbon-based fire is at the core of the economy, powering most of society’s primary machines, transportation, and much manufacturing. Renewable energy is not fire and cannot be used like fire.

For landscape architecture, the end of fossil-fueled fire is critical to materials and construction methods. Many of the primary building materials used by landscape architects require high temperatures that are primarily made with fossil fuels and that do not have a ready renewable energy substitute. Producing cement and steel requires extremely high temperatures presently achieved by the direct burning of fossil fuels. There have been experiments in developing methods to use electricity to create the needed temperatures, but there is no guarantee that there will be significant amounts of electrically made cement and steel in the future.

Additionally, there is no way to eliminate the release of large amounts of carbon dioxide that occur simply as a by-product of the production of cement, steel, and plastic. In the zero-carbon future, all the carbon released from such industrial processes must be directly offset through sequestration in plants and soil. This may be minimal, given the imperative to restore a stable climate by drawing excess carbon from the atmosphere, not simply by attempting to balance current emissions.

The ultimate result is that, in our all-electric future, there will likely be much less of the building materials we use now. This raises other ethical questions for landscape architects: For whom and to what purpose should these limited materials be used?

An all-electric future also directly affects current construction methods. Carbon-fueled machines are taken for granted on most projects. Without fossil fuels, heavy machinery must be powered with either electricity or some combustible substance such as biodiesel. It is not feasible to electrify these machines using a fixed electric grid; imagine an excavator or backhoe connected to an overhead power line or even a power cord. Also, it appears that switching heavy machines to electric battery power is not possible given the physics of batteries. Alternative fuels such as biodiesel will likely be limited as well. Scaling up biofuels to come anywhere near the 35 billion barrels of oil a year the global economy currently consumes could negatively affect food production as energy crops are substituted for food crops.

Future travel of significant distance will also be at the mercy of electrical grids and even the wind. Trains and sailing ships will likely have a future, while airplanes and long-haul trucks might not. This will determine material choices and supply chains, but also the ability to serve clients. The travel radius imposed by the zero-carbon reality may be considerably smaller than today.

Landscape architects might wonder if these stark implications are just “fake news.” Unfortunately, climate change is not a hoax, and neither are the limits of an all-renewables-based economy. There appear to be no solutions to our predicament if we continue to burn fossil fuels. Current carbon emissions cannot be mitigated through massive tree planting. To do so would take tree planting over an area larger than the state of California just to offset one year’s global carbon emissions. We will run out of planet on which to plant trees, let alone food, before we run out of fossil fuels. While both reforestation and afforestation, in appropriate landscapes, are vital responses to global warming, their primary value is in drawing down carbon from the atmosphere, not masking massive emissions.

The various rating systems, known by their acronyms, are not a complete answer at this point. These systems rely on carbon efficiency as one measure of compliance in supposedly “green” projects. Carbon efficiency is important in the short term, but it is not the same as zero carbon, which means all carbon emissions on every project are directly balanced by documented sequestration in plants and soils.

Finally, there is a persistent belief that there are technological solutions to our predicament. But technology is not energy. Technology simply allows society to exploit energy in ways deemed beneficial. Ultimately, there appears to be no realistic technology that will allow society to keep burning fossil fuels without unimaginable consequences.

Our society is in the early stages of an epochal transition. The shapes and limits of the near future are becoming clear owing to the needed and urgent responses to climate change. However, even if nothing meaningful is done in response to climate change, humanity still faces the realities of resource depletion and ecosystem destruction. Addressing these crises is equally as vital as addressing climate change. For even in climate denial, those issues will remain, and then the climate will have been heated, perhaps intolerably. There is no escaping what Robert Louis Stevenson once termed the “banquet of consequences.”

Ultimately, the Paris Agreement’s imperative to end the fossil fuel era presents several fundamental questions for practitioners and teachers of landscape architecture, the answers to which may determine the fate of the profession. Some of these questions are: What is the essence of landscape architecture? Who benefits from landscape architecture? How is the work of landscape architecture done? How do the products of landscape architecture evolve? The longer it takes to address these questions, the more difficult it will be to adapt to the zero-carbon reality.

The world needs landscape architects more than ever, to help society adapt to climate change, to assist efficient and artful carbon drawdown, to restore ecosystems, and to improve quality of life for people. Yet, many of the tools and processes now considered essential to those tasks soon won’t be available because of carbon limits. Landscape architects must learn instead to work within the parameters of the zero-carbon future. In doing so, they will gain the practical experience and, more important, the moral authority to be the leaders of the climate-saving energy transition.

Steve Austin, ASLA, teaches landscape architecture, urban planning, and construction law at Washington State University.

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