Drawdown: The Most Comprehensive Plan Ever Proposed to Reverse Global Warming

by Paul Hawken

“When we try to pick out anything by itself, we find it hitched to everything else in the Universe.”

For more than a century, people have used this quote to describe the interconnectedness of ecosystems and the planetary ripple effects of everything from food to transport. It is also useful for describing the phenomenon of the grid: the dynamic web of electricity production, transmission, storage, and consumption that 85 percent of the world relies on. Increasingly, the phrase “global energy transition” gets bandied about, usually to describe a wholesale shift from fossil fuels to clean, renewable sources of energy. While this shift in sources is the crux of the matter when it comes to greenhouse gas emissions, broader change is afoot: a transformation of the entire grid system.

A groundbreaking 2016 study from the University of Oxford modeled the climate, health, and economic benefits of a worldwide transition to plant-based diets between now and 2050. Business-as-usual emissions could be reduced by as much as 70 percent through adopting a vegan diet and 63 percent for a vegetarian diet (which includes cheese, milk, and eggs). The model also calculates a reduction in global mortality of 6 to 10 percent. The potential health impact on millions of lives translates into trillions of dollars in savings: $1 trillion in annual health-care costs and lost productivity, and upwards of $30 trillion when accounting for the value of lives lost. In other words, dietary shifts could be worth as much as 13 percent of worldwide gross domestic product in 2050. And that does not begin to include avoided impacts of global warming.

IMPACT: Using country-level data from the Food and Agriculture Organization of the United Nations, we estimate the growth in global food consumption by 2050, assuming that lower-income countries will consume more food overall and higher quantities of meat as economies grow. If 50 percent of the world’s population restricts their diet to a healthy 2,500 calories per day and reduces meat consumption overall, we estimate at least 26.7 gigatons of emissions could be avoided from dietary change alone. If avoided deforestation from land use change is included, an additional 39.3 gigatons of emissions could be avoided, making healthy, plant-rich diets one of the most impactful solutions at a total of 66 gigatons reduced.

The food we waste contributes 4.4 gigatons of carbon dioxide equivalent into the atmosphere each year—roughly 8 percent of total anthropogenic greenhouse gas emissions. Ranked with countries, food would be the third-largest emitter of greenhouse gases globally, just behind the United States and China. A fundamental equation is off-kilter: People who need food are not getting it, and food that is not getting consumed is heating up the planet.

IMPACT: After taking into account the adoption of plant-rich diets, if 50 percent of food waste is reduced by 2050, avoided emissions could be equal to 26.2 gigatons of carbon dioxide. Reducing waste also avoids the deforestation for additional farmland, preventing 44.4 gigatons of additional emissions. We used forecasts of regional waste estimates from farm to household. This data shows that up to 35 percent food in high-income economies is thrown out by consumers; in low-income economies, however, relatively little is wasted at the household level.

As of 2014, clean cookstoves comprised just 1.3 percent of the addressable market. If adoption grows to 16 percent by 2050, reductions in emissions will amount to 15.8 gigatons of carbon dioxide.

Evidence points to a new wisdom: The world cannot be fed unless the soil is fed. Feeding the soil reduces carbon in the atmosphere.

From an estimated 108 million acres of current adoption, we estimate regenerative agriculture to increase to a total of 1 billion acres by 2050. This rapid adoption is based in part on the historic growth rate of organic agriculture, as well as the projected conversion of conservation agriculture to regenerative agriculture over time. This increase could result in a total reduction of 23.2 gigatons of carbon dioxide, from both sequestration and reduced emissions. Regenerative agriculture could provide a $1.9 trillion financial return by 2050 on an investment of $57 billion.

Regenerative practices such as tree intercropping use diversity to improve soil health and productivity and align with biological principles. Lower inputs, healthier crops, and higher yields are the outcome. Like many solutions in this book, tree intercropping is rarely undertaken to address global warming. Farmers practice it because it works better, though it declined in Europe for most of the twentieth century in the wake of the industrialization of agriculture. Like all regenerative land-use practices, it increases the carbon content of the soil and productivity of the land. Intercropping provides windbreaks that reduce erosion and creates habitat for birds and beneficial insects. Fast-growing annuals, susceptible to being flattened by wind and rain, can be protected. Deep-rooted plants can draw up subsoil minerals and nutrients for shallow-rooted ones. Vines or creepers have a ready trellis. Light-sensitive crops can be protected from excess sunlight. To top it off, tree intercropping is beautiful—chili peppers and coffee, coconut and marigolds, walnuts and corn, citrus and eggplant, olives and barley, teak and taro, oak and lavender, wild cherry and sunflower, hazel and roses. Triple-cropping is common in tropical areas, with coconut, banana, and ginger grown together. The possible combinations are endless.

IMPACT: Based on historic growth on large farming operations, our analysis projects the total area under conservation agriculture will continue growing from 177 million acres to peak at 1 billion acres by 2035. We assume that as regenerative agriculture becomes more widely used, farms that have already adopted conservation agriculture will convert to these more effective soil fertility practices in response to consumer demand for fewer harmful herbicides. The benefits of that conversion are counted by the regenerative agriculture solution. Nonetheless, conservation agriculture offers significant benefits in the interim, reducing carbon dioxide emissions by 17.4 gigatons based on average carbon sequestration rates of .15 to .25 tons of carbon per acre per year, depending on region. Implementation costs are low at $38 billion with a return of $2.1 trillion.

IMPACT: Two solutions influence family size and global population: educating girls and family planning. Because the exact dynamic between these solutions is impossible to determine, our models allocate 50 percent of the total potential impact to each. We assume that these impacts result from thirteen years of schooling, including primary through secondary education. According to the United Nations Educational, Scientific, and Cultural Organization, by closing an annual financing gap of $39 billion, universal education in low- and lower-middle-income countries can be achieved. It could result in 59.6 gigatons of emissions reduced by 2050. The return on that investment is incalculable.

Designing a net zero building means following energy use back to the source. There are multiple ways to reduce energy loads in building. Lighting can be reduced in favor of daylight wherever possible. Spaces are designed to encourage people to walk between floors instead of using elevators. Walls, windows, and ceilings have maximum insulating power (R-value) to retain heat in the winter and maintain coolness in the summer. Window louvers and overhangs are designed to receive sunlight in winter months, when the sun is lower, and to create needed shade in the summer, when the sun is more directly above. Electrochromic glass changes its opacity according to heat, sun, and the difference between indoor and outdoor temperature. If the window is next to you, it can be manually adjusted with an app on your smartphone. Heat exchangers are strategically placed to be sure every stray calorie is put to use. Passive solar gain is achieved by building orientation and artful fenestration. Air-conditioning uses natural ventilation principles from nature, such as termite mounds and belowground thermal mass, to create natural convection and cooling breezes.

IMPACT: In modeling green and cool roofs, we account for regional applications of each technology. If green roofs cover 30 percent of roof space by 2050 and cool roofs cover 60 percent, a total of 407 billion square feet of efficient roofing would be in place globally. Combined, these technologies could reduce carbon dioxide emissions by 0.8 gigatons at a cost of $1.4 trillion, thirty-year savings of $988 billion, and lifetime savings of $3 trillion.

IMPACT: Our analysis assumes that LEDs will become ubiquitous by 2050, encompassing 90 percent of the household lighting market, and 82 percent of commercial lighting. As LEDs replace less-efficient lighting, 7.8 gigatons of carbon dioxide emissions could be avoided in residences and 5 gigatons in commercial buildings. Additional gains, not counted here, will come from replacing off-grid kerosene lighting with solar-LED technology.

IMPACT: Heating and cooling of residential and commercial building space requires more than 13,000 terawatt-hours of energy and is estimated to increase to more than 18,000 terawatt-hours by 2050. This energy use comes from on-site fuel combustion and electricity-based systems—from gas furnaces to air-conditioning units. High-efficiency heat pumps reduce fuel consumption to zero and use less electricity to generate heating and cooling. Current adoption is low at .02 percent of the market, but we estimate rapid growth as costs continue to decrease by up to 25 percent by 2050. For a cost of $119 billion in addition what would be spent on conventional technologies, operating savings could reach $1.5 trillion over three decades and $3.5 trillion over the technology’s lifetime. Emissions reductions in this scenario come to 5.2 gigatons of carbon dioxide.