Technological Shortcomings

To date, vast resources—both human and financial—have been allocated to tackle the ecological crises exacerbated by human activity. Innovations like electric vehicles, geothermal energy, solar power, wind energy, and biomass are indeed impressive. However, their implementation at a scale sufficient to replace all carbon-emitting alternatives seems daunting, if not impossible.

In my view, it is unfeasible.

Electric vehicles still require energy, albeit less than their predecessors. However, energy must still be generated to power them—and our buildings. This includes the production and disposal of batteries and raw materials. Geothermal energy relies on maintaining underground equilibrium, while solar and wind energy necessitate extensive resources for installation and maintenance, as well as systems for energy distribution according to demand. Biomass creates waste that must be managed, and tidal turbines can disrupt aquatic ecosystems.

In summary, all technological solutions will necessitate creation and maintenance, and hence cannot be classified as 'sustainable' by Bill Reed's standards. Moreover, they introduce various disruptions to their surrounding ecosystems.

Are these methods better than current practices? Absolutely. However, as Bill reminded me, “Doing less bad is not the same as doing good.”

So, what’s the way forward?

The answer, unsurprisingly, lies within nature—at the ecosystem level.

By the Numbers

Consider these three facts: - The United States emits 5,130 million metric tons of carbon dioxide related to energy annually, accounting for about 15% of the global total of 33,621 million metric tons. - Approximately 400 million acres of land—around 20% of the U.S. total—is allocated to cropland, or non-animal food production, which globally occupies 12.7% of Earth's surface. - On average, 106 metric tons of carbon are sequestered per acre of forest ecosystem.

When these figures are combined, they paint a revealing picture. In the U.S., merely 48 million acres of forest could completely absorb the 5.13 billion metric tons of carbon emitted annually. In other words, if we were to convert just 12% of current cropland into forests—essentially rewilding it—we could offset all carbon emissions from Americans each year, without altering how we fuel vehicles, heat and cool buildings, or conduct our daily lives.

Rewilding a mere 12% of U.S. cropland (by transitioning to vertical farms) could completely neutralize American carbon production, without any additional changes.

While I'm not advocating for maintaining the status quo—our environmental impact extends beyond carbon emissions—rewilding could create a self-sustaining carbon-balancing ecosystem that thrives without human intervention, as Bill Reed suggests.

But how would we secure food?

The Vertical Farm

First, the alarming news: - In the past 40 years, one-third of the world’s arable land has been depleted. - By 2050, per capita availability of arable land is projected to decline by 66%. - One-third of the remaining soil has been “moderately to highly degraded” due to modern farming practices, including pesticides and mono-cropping. - Freshwater consumption has exceeded the “planetary boundary” of 4,000 cubic km annually, reaching an unsustainable 10,800 cubic km, as exemplified by Lake Mead's dramatic capacity loss. - A Scientific American article warns: “Only 60 Years of Farming Left If Soil Degradation Continues,” underscoring that it takes 1,000 years to generate just 3 cm of topsoil.

Now, for the positive developments. As noted in my work, Rebalancing the World is Dead Simple: - Hydroponics can save 70–90% of water used in traditional farming. - Aquaponics can conserve 90%. - Aeroponics consumes just 2% of the water that conventional agriculture requires. - Vertical farms can yield ten times more produce per acre than traditional farms. - With the right density and technology, vertical farms can potentially achieve yields up to 240 times greater than conventional farms, as demonstrated by the San Francisco startup Plenty. - Traditional farming loses 20–40% of outdoor crops to disease and pests—issues non-existent in vertical farms. - Vertical farms enable food production anywhere and year-round, independent of weather and climate.

Vertical farming initiatives are emerging globally, and the technologies that fuel them—solar energy, nutrient delivery, and growth optimization—are still evolving. By any measure, vertical farms show great promise, and we can expect to see more about them in the near future.

Yet, there are only 74 acres of operational vertical farms worldwide today.

When I advocate for vertical farming as a solution to climate change—especially when paired with the rewilding of land resources—three common objections arise:

1. “Is food grown in buildings as nutritious as soil-grown produce?”
2. “Can't we simply adopt more sustainable farming methods, like regenerative farming?”
3. “Isn't the energy required for vertical farms unsustainable, negating any benefits?”

Let’s address each concern.

Nutrition and The Vertical Farm

Marion Nestle, an esteemed authority in nutritional health, remarks: > “While soil is excellent for plant growth, hydroponics has advanced significantly. I've seen hydroponic producers analyze their leafy greens for essential nutrients, and the levels are often within normal ranges, sometimes even higher.”

She emphasizes that plants generate their own vitamins, alleviating concerns about their nutritional content. Although mineral levels can vary based on the fertilizers used—similar to traditional farming—these can be supplemented in vertical farms, potentially improving upon conventional methods.

Nestle adds: > “Nutritional content varies among produce types, depending on harvest timing, storage, and handling from farm to fork.”

Ultimately, it is our choices regarding food—what we consume, how much, and its freshness—that determine nutritional value.

Regenerative Farming

Regenerative farming consistently outperforms conventional methods in evaluations. This approach incorporates cover crops, animal grazing, and natural fertilizers—essentially recycling nutrients.

If I had to choose, I would certainly favor regenerative farming, regardless of the cost.

However, this approach has two significant limitations. First, the soil and water usage of regenerative farming resembles that of conventional methods. In other words, it still encroaches on natural ecosystems, consuming substantial water resources.

Second, farming—whether regenerative or traditional—requires constant human oversight to thrive. Thus, according to Bill Reed's definition, it cannot be considered sustainable.

David Montgomery, a geologist and author, noted in an NBC article that while regenerative agriculture can sequester carbon, there is a finite limit to how much carbon can be stored in soil.

He further cautions: > “Claims that regenerative agriculture can reverse climate change are overstated. While it may contribute to reducing atmospheric carbon, such efforts are easily reversible.”

He continues: > “If we invest in regenerative agriculture and later decide to till the land, we negate all benefits. We must establish policies to ensure that today's regenerative practices are beneficial in the future.”

Without proper policies and adherence to sustainable practices on a global scale, regenerative farms may release their carbon back into the atmosphere if the land is disturbed.

Conversely, forests require no human involvement beyond the commitment to leave them undisturbed.

Therefore, to ensure human prosperity in the long term, we must rethink land use and modernize our food production systems.

This brings us back to vertical farming.

Vertical Farms: Energy Consumption

The final concern raised by critics of vertical farming is indeed valid. While sunlight is free when it illuminates plants, indoor vertical farms rely heavily on artificial lighting to compensate for the absence of natural light. Some estimates suggest that LED lighting accounts for 65% of the total energy consumption in these facilities.

Critics rightfully argue that if non-renewable energy sources are used to meet these demands, vertical farms could generate more pollution than traditional farms or greenhouses.

In my architectural practice, DIALOG, we have embarked on research to evaluate vertical farming from multiple angles, including technology, building systems, business models, public engagement, policy implications, and nutritional health—all aimed at assessing the viability of incorporating this powerful sustainability solution.

My engineering colleague, Mara Baum, raised the energy issue at the outset of our investigation.

For any vertical farming initiative to be deemed sustainable, it must generate as much energy as it consumes and manage its waste in a closed-loop system. This applies to energy production (primarily lighting), water management, and waste generated from food and aquaculture operations.

The good news is that we have the capacity to create carbon-neutral buildings, and utilizing green energy technologies is significantly less harmful to the environment than conventional fossil fuel sources.

Moreover, the energy required to establish and operate a net-zero vertical farm would be offset by the reforestation allowed by its creation.

This transition can shift our approach from “doing less bad” to “doing good,” resulting in new sustainable carbon sinks, nutritious food, reduced waste, effective water and soil conservation, and greater access to healthy food closer to consumers.

Final Thoughts

Transitioning to electric vehicles, overhauling the energy grid, and updating every building globally is an immense challenge. Although no official count exists, there are likely around four billion buildings worldwide and 1.4 billion motor vehicles navigating among them.

Additionally, there are 195 nations, each with distinct political ideologies, priorities, economic systems, and infrastructures.

It seems impractical to expect all these entities to modernize simultaneously. Humans—especially politicians, corporate leaders, and individuals—often lack the consistency, foresight, and courage necessary for such comprehensive progress.

Therefore, our best course of action is to incrementally design and construct better buildings where feasible and promote electric vehicles to those willing to adopt them.

Ultimately, we must recognize that the only way to ensure the planet can withstand the pressures we place upon it—specifically regarding carbon emissions—is to restore enough forested land so that nature can maintain its own ecosystems without human interference.

In other words, we need to rewild a sufficient amount of cropland and allow nature to recover on its own.

This fundamental concept of rewilding and then allowing nature to thrive struck me when I encountered a compelling op-ed in the New York Times, which examined the effects of climate change across 193 countries.

As I noted in Rebalancing the Earth is Dead Simple, I found a glimmer of hope: > “Most countries are striving for carbon neutrality. Suriname, which is 93% forested, is one of only three carbon-negative nations in the world.”

Suriname’s carbon-negative status stems from its ample forest cover, which can absorb more carbon than is produced by its human activities.

This realization led me to conclude that as long as nature can absorb our impacts, both it and humanity will be alright.

Thus, the crucial question remains: Can we preserve enough natural forests on Earth to absorb our carbon emissions?

I believe we have a clear path forward.

Given that food production occupies 12.7% of the planet’s land (38% including livestock), consumes 70% of the global freshwater supply, rapidly depletes soil health, and contributes to desertification, we must convert 317 million acres of farmland (or 7% of the total cropland) back into forest to offset global carbon emissions.

My perspective is that the investment required to develop new or adapt existing buildings for global food production—especially within urban areas—offers a far more attainable goal than attempting to convert every building and vehicle on the planet to approaches that achieve carbon neutrality.

Ultimately, it circles back to Bill Reed's insight: “Sustainability is the ability to thrive in perpetuity without human intervention.” Nature embodies this principle through its ecosystems.

While vertical farms themselves may not be sustainable in isolation, modernizing and potentially urbanizing our food production could free the land necessary to rewild former farmland into thriving, biologically diverse, carbon-sequestering environments. Such forest ecosystems are inherently sustainable in the truest sense of the word.

If we allow a portion of agricultural land to revert to a natural state while meeting our food needs through advanced methods, we may create the opportunity to address other significant challenges we face and ultimately overcome them.