Solutions

Each solution reduces greenhouse gases by avoiding emissions and/or by sequestering carbon dioxide already in the atmosphere.

The objective of the solutions list is to be inclusive, presenting an extensive array of impactful measures already in existence. The list is comprised primarily of “no regrets” solutions—actions that make sense to take regardless of their climate impact since they have intrinsic benefits to communities and economies. These initiatives improve lives, create jobs, restore the environment, enhance security, generate resilience, and advance human health.

In our book Drawdown, each solution is measured and modeled to determine its carbon impact through the year 2050, the total and net cost to society, and the total lifetime savings (or cost). The exception to this are our "Coming Attraction" solutions, which are a window into what is still emerging. For these solutions, we did not measure cost, savings, or atmospheric impact, but we illuminate technologies and concepts whose growth we will continue to watch. 

Solutions by Rank

Rank Solution Sector TOTAL ATMOSPHERIC CO2-EQ REDUCTION (GT) Net Cost (BILLIONS US $) Savings (BILLIONS US $)
2 Wind Turbines (Onshore) Electricity Generation 84.60 $1,225.37 $7,425.00
8 Solar Farms Electricity Generation 36.90 $-80.60 $5,023.84
10 Rooftop Solar Electricity Generation 24.60 $453.14 $3,457.63
18 Geothermal Electricity Generation 16.60 $-155.48 $1,024.34
20 Nuclear Electricity Generation 16.09 $0.88 $1,713.40
22 Wind Turbines (Offshore) Electricity Generation 14.10 $545.30 $762.50
25 Concentrated Solar Electricity Generation 10.90 $1,319.70 $413.85
29 Wave and Tidal Electricity Generation 9.20 $411.84 $-1,004.70
30 Methane Digesters (Large) Electricity Generation 8.40 $201.41 $148.83
34 Biomass Electricity Generation 7.50 $402.31 $519.35
See all solutions by rank

Solutions by Sector

Choose a sector:

Electricity Generation
Food
Women and Girls
Buildings and Cities
Land Use
Transport
Materials
Coming Attractions
Show All
Electricity Generation

The Electricity Generation sector currently accounts for around 40 percent of annual greenhouse gas emissions to the atmosphere, making it the highest-emitting sector in the world. Of total worldwide electricity generation, fossil fuels represent 67 percent, nuclear 11 percent, and renewable energy sources just over 24 percent and growing. In the last few years, however, the competitiveness of renewable sources for electricity generation has continued to increase due to the price evolution and the efficiency improvements of these technologies.

Project Drawdown’s Electricity Generation Sector includes both solutions for electricity generation and enabling technologies that foster large-scale integration of renewable energy sources.

Sector Summary: Electricity Generation

Food

The essential human activity of eating is responsible for a major share of greenhouse gas emissions today: crop and livestock production is the source of about 1/8 of anthropogenic emissions. Land clearing (which is mostly for agriculture) is the source of another 1/8 of emissions.

Project Drawdown’s Food Sector includes agricultural production (crops and livestock) as well as food preparation, consumption, and waste. Many of the supply-side agricultural solutions reduce emissions from farming and ranching, while also sequestering significant amounts of carbon. Demand-side solutions like a plant-based diet and reduced food waste reduce the need for land clearing.

Sector Summary: Food

Women and Girls

Climate change is not gender neutral. Due to existing inequalities, women and girls are disproportionately vulnerable to its impacts, from disease to natural disaster. At the same time, women and girls are pivotal to addressing global warming successfully—and to humanity’s overall resilience.

Project Drawdown’s Women and Girls Sector is deceptively small in number: its three solutions focus on the majority of humanity, and represent powerful ways to reduce greenhouse gas emissions (combined, educating girls and family planning are the #1 Drawdown solution). These solutions show that enhancing the rights and well-being of women and girls could improve the future of life on this planet.

Sector Summary: Women and Girls

Buildings and Cities

Dense urban human settlement – the cities of the world and the buildings and infrastructure that comprise them – account for a significant percentage of human energy use, mostly for heating and cooling. Ergo, they are a significant source of greenhouse gas emissions. The rapid urbanization of humanity ushered in inefficient design of buildings and infrastructure; Project Drawdown’s Buildings and Cities Sector models several solutions that address the operating inefficiencies of dwelling in and using buildings, and of living in cities.

Sector Summary: Buildings and Cities

Land Use

Deforestation and degradation of forest ecosystems are responsible for about 1/8 of anthropogenic greenhouse gas emissions today. Land use solutions reduce emissions from deforestation and degradation of ecosystems. Forests, peatlands, and coastal wetlands provide critical ecosystem services as well, while timber and biomass crops produce important feedstocks for construction, paper, energy, and other uses.

Project Drawdown’s Land Use Sector includes the protection and restoration of high-carbon ecosystems such as forests and wetlands, as well as the production of perennial timber and biomass crops.

Sector Summary: Land Use

Transport

Transport produces 7 gigatons of carbon dioxide-equivalent greenhouse gas emissions annually, or 23 percent of energy-related emissions, which is around 14 percent of all emissions. Though some modes of transport can only currently be made more efficient at using existing fossil fuels, others have alternative fuels and/or can be avoided completely using information and communication technologies.

Project Drawdown’s Transport Sector examines 13 of these transport solutions, some of which are included in the Buildings and Cities section of Drawdown the book. Together, they form key parts of making the global transport sector less carbon-intensive.

Sector Summary: Transport

Materials

The most important insight about materials in the twentieth century was biologist John Todd’s, when he coined the phrase “Waste equals food.” That happens to be the exact practice of all living systems, but at the time Todd made his observation, it was in stark contrast to the realities of the manufacturing world. Industry has come a long way since then, with responsible companies now paying close attention to where they source their materials and what happens to them after the useful life of their products. That being said, society is at the very beginning of redesigning and reimagining the materials used in products and structures, as well as the means by which they can be reduced, reused, and recycled. The newest discoveries are not covered here, of course, but this section details the common techniques and technologies critical to the effort to reverse global warming. To underline that fact, the number-one solution is contained within this sector.

Sector Summary: Materials

Coming Attractions

Project Drawdown’s Coming Attractions Sector contains previews of the world to come: technologies and solutions that do not yet have enough scientific and financial information to model, but that could emerge within the next several years as game-changers in the effort to reverse global warming. Though this sector does not cover nearly all climate solutions currently in development, it depicts a representative sample of the staggering invention and innovation that permeates all Drawdown sectors.

Each Coming Attraction is associated with a different Drawdown sector, and is listed in the Sector Summary for that sector.

Coming Attractions
A Cow Walks Onto A Beach
Asparagopsis taxiformis, a species of seaweed, shows promise for reducing methane emissions from livestock—currently 6 to 7 percent of annual greenhouse gas emissions.
Land Use
Afforestation
Afforestation—creating forests where there were none before—creates a carbon sink, drawing in and holding on to carbon and distributing it into the soil.
Transport
Airplanes
The airline industry produces at minimum 2.5 percent of emissions, and it is growing. Fuel efficiency measures are on the rise to reduce that impact.
Materials
Alternative Cement
Cement, a vital material for infrastructure, generates 5 to 6 percent of annual emissions. The key strategy to reduce them is to change its composition.
Coming Attractions
Artificial Leaf
The artificial leaf is technology inspired by photosynthesis. It combines solar energy, water, and carbon dioxide, to feed bacteria that synthesize energy-dense fuel.
Coming Attractions
Autonomous Vehicles
Autonomous vehicles are on the rise. They have the potential to shrink the auto fleet and accelerate ridesharing and the adoption of electric vehicles.
Land Use
Bamboo
Bamboo rapidly sequesters carbon in biomass and soil and can thrive on degraded lands. It has more than 1,000 uses, from buildings to food to paper.
Buildings and Cities
Bike Infrastructure
Infrastructure is essential for supporting safe, pleasant, and abundant bicycle use—which can relieve city congestion, improve public health, and reduce emissions from cars.
Food
Biochar
Biochar results from slowly baking biomass in the absence of oxygen. Retaining most of the feedstock’s carbon, biochar can be buried for sequestration, while enriching soil.
Electricity Generation
Biomass
Biomass energy is a “bridge” solution for transitioning to 100 percent clean, renewable energy. Using sustainable feedstock—waste biomass or perennial crops—is crucial.
Materials
Bioplastic
Ninety percent of plastics could be derived from plants instead of fossil fuels. Bioplastics can be biodegradable and often have lower emissions.
Buildings and Cities
Building Automation
Building automation systems serve as the “brain” of large commercial buildings. Controlling temperature, lighting, and more, they can improve energy efficiency and occupants’ comfort.
Coming Attractions
Building With Wood
High-performance wood materials are transforming construction. They can reduce emissions by (1) sequestering and storing carbon and (2) avoiding emissions of cement and steel.
Transport
Cars
Hybrid cars pair an electric motor and battery with an internal combustion engine. The combination makes them more efficient, improving fuel economy and lowering emissions.
Food
Clean Cookstoves
Traditional cooking practices produce toxic smoke and 2 to 5 percent of annual greenhouse gas emissions. Clean cookstoves reduce emissions and protect human health. 
Land Use
Coastal Wetlands
The world’s salt marshes, mangroves, and sea grasses provide vital habitat, flood protection, and water filtration, and sequester huge amounts of carbon in plants and soil.
Electricity Generation
Cogeneration
Power plants produce large amounts of waste heat. Cogeneration systems capture that thermal energy and put it to work—for district heating or additional electricity.
Food
Composting
From backyard bins to industrial-scale operations, composting food waste converts organic material into stable soil carbon and valuable fertilizer, averting methane emissions.
Electricity Generation
Concentrated Solar
Concentrated solar power uses solar radiation as its primary fuel. Arrays of mirrors concentrate incoming rays to heat a fluid, produce steam, and turn turbines.
Food
Conservation Agriculture
Conservation agriculture avoids tilling and employs cover crops and crop rotation. By protecting the soil, it makes land more resilient and sequesters carbon.
Coming Attractions
Direct Air Capture
Direct air capture systems are a nascent sequestration technology. Functioning like a chemical sieve and sponge, they capture carbon dioxide from air and release it in purified form.
Buildings and Cities
District Heating
With district systems, a central plant channels hot and/or cool water via a network of pipes to many buildings—heating and cooling them more efficiently.
Women and Girls
Educating Girls
Education lays a foundation for vibrant lives for girls and women, their families, and their communities. It also avoids emissions by curbing population growth.
Transport
Electric Bikes
Electric bikes get a boost from a small battery-powered motor. They are the most environmentally sound means of motorized transport in the world today.
Transport
Electric Vehicles
Electric vehicles are the cars of the future. If powered by solar energy, their carbon dioxide emissions drop by 95 percent compared to gasoline-powered vehicles.
Electricity Generation
Energy Storage (Distributed)
Standalone batteries and electric vehicles make it possible to store energy at home or work. They ensure supply even when variable renewables are not producing.
Electricity Generation
Energy Storage (Utilities)
Energy storage—daily, multiday, and longer-term or seasonal—is vital to reduce emissions from polluting “peaker” plants and accommodate the shift to variable renewables.
Coming Attractions
Enhanced Weathering of Minerals
Natural weathering of silicate rock sequesters carbon dioxide. Enhanced weathering aims to hasten that process by milling rock powder and applying it to landscapes.
Women and Girls
Family Planning
Securing women’s right to voluntary, high-quality family planning dramatically improves the health and well-being of women and their children. It also avoids emissions.
Food
Farmland Irrigation
Pumping and distributing water requires large quantities of energy. Drip and sprinkler irrigation, among other practices and technologies, make water use more precise and efficient.
Food
Farmland Restoration
The world’s abandoned farmland is an opportunity for drawdown. Restoring it sequesters carbon and can improve food security, farmers’ livelihoods, and ecosystem health.
Land Use
Forest Protection
With mature canopy trees and complex understories, forests contain 300 billion tons of carbon and are the greatest repositories of biodiversity on the planet.
Electricity Generation
Geothermal
Geothermal power—literally “earth heat”—taps into underground reservoirs of steamy hot water, which can be piped to the surface to drive turbines that produce electricity.
Buildings and Cities
Green Roofs
Green roofs use soil and vegetation as living insulation. Cool roofs reflect solar energy. Both reduce building energy use for heating and/or cooling.
Electricity Generation
Grid Flexibility
For electricity supply to become predominantly or entirely renewable, the grid needs to become more flexible and adaptable than it is today.
Buildings and Cities
Heat Pumps
Heat pumps transfer heat from a cold space to a hot one. Highly efficient, they can dramatically lower building energy use for heating and cooling.
Transport
High-speed Rail
High-speed rail is the fastest way to travel distances between 100 to 700 miles. Compared to driving or flying, it reduces emissions up to 90 percent.
Materials
Household Recycling
Household recycling can reduce emissions because producing new products from recovered materials often saves energy. It also reduces resource extraction and creates jobs.
Coming Attractions
Hydrogen-Boron Fusion
Tri Alpha Energy has achieved one-half of the nuclear fusion equation. It could herald clean, safe, affordable energy to take the world beyond fossil fuels.
Coming Attractions
Hyperloop
The promise of Hyperloop is speed. The virtue is moving people and cargo with 90 to 95 percent less energy than planes, trains, or cars.
Food
Improved Rice Cultivation
Flooded rice paddies produce large quantities of methane—10 percent of agricultural emissions. Techniques exist to reduce methane, while improving production and sequestering carbon.
Electricity Generation
In-Stream Hydro
Placed within a free-flowing river or stream, in-stream turbines capture water’s energy without a dam. In remote communities, they can replace expensive, dirty diesel generators.
Land Use
Indigenous Peoples’ Land Management
Growing the acreage under secure indigenous land tenure can increase above- and belowground carbon stocks and reduce greenhouse gas emissions from deforestation.
Coming Attractions
Industrial Hemp
Hemp is a global warming solution primarily because of what it can replace: cotton. Cotton has high chemical use and depends on fossil fuel inputs.
Materials
Industrial Recycling
Industrial recycling reduces emissions when new products are made from recovered materials, rather than virgin resources. It can also address the challenge of resource scarcity.
Buildings and Cities
Insulation
Insulation is one of the most cost-effective ways to make buildings more energy efficient—both in new construction and through retrofitting older buildings.
Coming Attractions
Intensive Silvopasture
Intensive silvopasture intercrops a leguminous woody shrub with grasses and trees. Through rapid rotational grazing, livestock yields increase alongside carbon sequestration in soil.
Buildings and Cities
Landfill Methane
Landfills are a top source of methane emissions. Instead, landfill methane can be captured, preventing emissions, and used as a fairly clean energy source.
Buildings and Cities
LED Lighting (Commercial)
Lighting accounts for 15 percent of global electricity use. LEDs (light emitting diodes) require less energy and create less waste heat than other bulbs.
Buildings and Cities
LED Lighting (Household)
By transferring most of their energy use into creating light—rather than heat, like older technologies—LEDs reduce electricity consumption and air-conditioning loads.
Coming Attractions
Living Buildings
The Living Building Challenge holistically defines how buildings can benefit both people and planet. One key criteria: Living buildings produce more energy than they use.
Food
Managed Grazing
Managed grazing imitates the activity of migratory herds to improve soil health, carbon sequestration, water retention, and forage productivity.
Coming Attractions
Marine Permaculture
Marine permaculture utilizes floating, latticed structures designed to grow rich kelp forests and foster marine life. It could sequester billions of tons of carbon dioxide.
Transport
Mass Transit
Riding a streetcar, bus, or subway—rather than driving a car or hailing a cab—averts greenhouse gases, relieves traffic congestion, and reduces air pollution.
Electricity Generation
Methane Digesters (Large)
Industrial-scale anaerobic digesters control decomposition of organic waste, and thus its methane emissions. They also produce biogas, an energy source, and digestate, a nutrient-rich fertilizer.
Electricity Generation
Methane Digesters (Small)
At backyard- and farmyard-scale, anaerobic digesters are used to manage organic waste. They control methane emissions, while producing biogas (an energy source) and digestate (nutrient-rich fertilizer).
Electricity Generation
Micro Wind
With capacity of 100 kilowatts or less, micro wind turbines are often used to pump water, charge batteries, and provide electrification in rural locations.
Coming Attractions
Microbial Farming
Microbes have the potential to dramatically reduce the need for synthetic fertilizers, pesticides, and herbicides, while improving crop yields and plant health.
Electricity Generation
Microgrids
A microgrid is a localized grouping of distributed energy sources, like solar and wind, together with energy storage or backup generation and load management tools.
Food
Multistrata Agroforestry
Multistrata agroforestry blends taller trees and one or more layers of crops. It achieves high rates of carbon sequestration, similar to forests, while producing food.
Buildings and Cities
Net Zero Buildings
A net zero building is one that has zero net energy consumption, producing as much energy, through onsite renewables, as it uses in a year.
Electricity Generation
Nuclear
Nuclear power is complex, expensive, and risky, but it has the potential to avoid emissions from fossil fuel electricity. Project Drawdown considers it a "regrets solution."
Food
Nutrient Management
When overused, nitrogen fertilizers destroy soil organic matter, pollute waterways, and create nitrous oxide. They can be more efficiently managed to reduce these negative impacts.
Coming Attractions
Ocean Farming
Small-scale ocean farms have the potential to provide sustainable food and biofuel, while oysters filter nitrogen pollution and seaweed sequesters carbon dioxide.
Coming Attractions
Pasture Cropping
In a pasture cropping system, annual crops are grown in a perennial pasture. Double-cropping grains and animals sequesters carbon and improves farm health and productivity.
Land Use
Peatlands
Although peatlands cover just 3 percent of the earth’s land area, they are second only to oceans in the amount of carbon they store.
Land Use
Perennial Biomass
Using perennial bioenergy crops (e.g., switchgrass, silver grass, willow, eucalyptus) rather than annuals (e.g., corn) reduces emissions and raises carbon sequestration in soil.
Coming Attractions
Perennial Crops
Perennial crops sequester carbon because they leave the soil intact. Researchers are pursuing grain, cereal, and oilseed plants that are perennial food providers.
Food
Plant-Rich Diet
Meat-centric diets come with a steep climate price tag: one-fifth of global emissions. Plant-rich diets dramatically reduce emissions and rates of chronic disease.
Materials
Recycled Paper
Half of paper is used once and then trashed. Recycling makes paper’s journey circular, rather than a straight line from logging to landfill, which reduces emissions.
Food
Reduced Food Waste
Producing uneaten food squanders resources and generates 8 percent of emissions. Interventions can reduce waste at key points, as food moves from farm to fork.
Materials
Refrigerant Management
The primary chemical refrigerant, HFCs, is a potent greenhouse gas. Emissions are avoided by managing leaks and disposal and by phasing out the use of HFCs.
Food
Regenerative Agriculture
The practices of regenerative agriculture increase carbon-rich soil organic matter. Enhancing and sustaining the health of the soil sequesters carbon and improves productivity.
Coming Attractions
Repopulating the Mammoth Steppe
A vast ecosystem called the mammoth steppe once dominated the frozen north. Restoring grazers and grassland could prevent carbon-rich permafrost from thawing and releasing emissions.
Buildings and Cities
Retrofitting
Up to 80 percent of the energy buildings consume is wasted. Retrofitting them can address waste through efficient insulation, heating and cooling systems, and lighting.
Transport
Ridesharing
Ridesharing pairs drivers and riders who share common origins, destinations, or stops en route. When trips are pooled, people split costs, ease traffic, and curtail emissions.
Electricity Generation
Rooftop Solar
Rooftop solar is spreading as its cost falls, driven by incentives to accelerate growth, economies of scale in manufacturing, and advances in photovoltaic technology.
Transport
Ships
Shipping produces 3 percent of global emissions. Fuel-saving ship design, onboard technologies, and practices can have a sizable impact, because of huge shipping volumes.
Food
Silvopasture
Silvopasture is an ancient practice, integrating trees and pasture into a single system for raising livestock. It sequesters carbon while improving animal health and productivity.
Buildings and Cities
Smart Glass
Compared to walls, windows are inefficient insulators. Smart glass can respond to sunlight and weather, reducing a building’s energy load for lighting, heating, and cooling.
Coming Attractions
Smart Grids
With two-way communication between suppliers and consumers, smart grids accommodate the fluctuations of wind and solar power. They also improve grid stability and overall efficiency.
Coming Attractions
Smart Highways
The world’s first sustainable highway is being pioneered south of Atlanta, Georgia, emphasizing electric vehicle infrastructure and solar power to reduce carbon emissions.
Buildings and Cities
Smart Thermostats
Thermostats are mission control for heating and cooling homes. Smart thermostats use algorithms and sensors to learn and become more energy efficient over time.
Electricity Generation
Solar Farms
Solar farms tap the sun’s virtually unlimited, clean, and free fuel, using large-scale arrays of hundreds, thousands, or in some cases millions of photovoltaic panels.
Electricity Generation
Solar Water
Water heating is a major energy use. Solar water heaters use the sun’s radiation and can reduce that energy consumption by 50 to 70 percent.
Coming Attractions
Solid-state Wave Energy
Solid-state wave energy technology converts the ocean’s kinetic energy without external moving parts. It is more robust in marine environments, rich with untapped renewable energy.
Food
System of Rice Intensification
SRI is a holistic approach to sustainable rice cultivation. It improves soil, lowers inputs of seeds and water, and increases yields, while reducing emissions.
Transport
Telepresence
Telepresence integrates high-performance visual, audio, and network technologies to enable people who are geographically separated to interact. By reducing travel, it can reduce emissions.
Land Use
Temperate Forests
Ninety-nine percent of temperate forests have been altered in some way—timbered, converted to agriculture, disrupted by development. Restoring them sequesters carbon and revives ecosystems.
Transport
Trains
Most trains are powered by diesel-burning engines. Technology and operations can improve fuel efficiency, and rail electrification has the potential to provide nearly emissions-free transport.
Food
Tree Intercropping
Like all regenerative land-use practices, tree intercropping—intermingling trees and crops—increases the carbon content of the soil and productivity of the land.
Land Use
Tropical Forests
Tropical forests have suffered extensive clearing, fragmentation, degradation, and depletion of biodiversity. Restoring them may sequester as much as six gigatons of carbon dioxide per year.
Food
Tropical Staple Trees
Tropical staple trees provide important foods, such as bananas and avocado. Compared to annual crops, they have similar yields but higher rates of carbon sequestration.
Transport
Trucks
Road freight is responsible for about 6 percent of global emissions. Increasing fuel efficiency in both new trucks and existing fleets can significantly reduce emissions.
Buildings and Cities
Walkable Cities
Walkable cities prioritize two feet over four wheels through careful planning and design. As people need to drive less and want to walk more, emissions decrease.
Electricity Generation
Waste-to-Energy
Incineration, gasification, and pyrolysis are means of deriving energy from trash. A transitional solution, waste-to-energy can reduce emissions, but has high social and environmental costs.
Buildings and Cities
Water Distribution
Pumping water requires enormous amounts of energy. By minimizing leaks in water-distribution networks—currently wasting 8.6 trillion gallons annually—both energy and water are saved.
Materials
Water Saving - Home
Cleaning, transporting, and heating water requires energy. More efficient fixtures and appliances can reduce home water use by 45 percent, thereby reducing emissions.
Electricity Generation
Wave and Tidal
Wave- and tidal-energy systems harness natural oceanic flows—among the most powerful and constant dynamics on earth—to generate electricity.
Electricity Generation
Wind Turbines (Offshore)
With competitive costs and investment growing, offshore wind energy is at the crest of initiatives to supply the world with clean power.
Electricity Generation
Wind Turbines (Onshore)
Proliferation of turbines, dropping costs, and heightened performance mean onshore wind farms are at the forefront of initiatives to address global warming.
Women and Girls
Women Smallholders
If women smallholders receive equal farming resources and land rights, their yields will rise by 20 to 30 percent, avoiding emissions from deforestation.

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