Happy Earth Day
Today is April 22nd, Earth Day! A day to take a moment to appreciate this extraordinary planet we call home. There are trillions and trillions of planets out there in the Universe, but this one is particularly special - it’s the only planet we know of that contains life.
We humans have lived for only 0.0044% of Earth’s 4.5 billion years! Over Earth’s long history, the climate has varied dramatically, with average global temperatures ranging from ~45℉ to 90℉ (global average is ~60°F today), through ice ages and great heats.1 Species have come and gone through many mass extinction events, with over 90% of life wiped out at a time! Fortunately, life has continued to build anew.
As we talk about human-driven climate change, it can be easy to conflate “hurting Earth” with “hurting life we love on Earth.” The truth is, Earth will be just fine no matter what we do. Whatever we spew into the atmosphere will eventually come back into a form of balance over hundreds of millions of years; carbon will be reabsorbed, ice sheets will melt and freeze again, the soils we are depleting today will be replenished by the ocean cycles, the sun will still set and fall each day. The question is not “will Earth be okay?” the question is “will we and other forms of life survive?” Given the short window of time we’ve lived on this Earth, the answer is anything but certain.
We are guests on this gracious planet, and it’s on us to remember that the delicate balance we rely on matters much less to our host than it does to the life we cherish on it. So thank you Earth for being a 5 start host all around, even if we’re letting the heating run a bit too high.
Agriculture, Forestry, and Land Use - 19% of Emissions
Now that we’ve taken a deep breath of air, enjoyed the trees, and contemplated our existence, what better way to celebrate Earth Day than by looking at how we use Earth’s land and resources through agriculture?
When it comes to agriculture emissions, the main culprits are methane and nitrous oxide, which represent more than 80% of all greenhouse gas emissions in the agriculture, forestry, and land-use sector.2
Emissions by sector (CO2 Equivalent). World average 2000-2018.3
Farming solutions that can be implemented today
There are many techniques available to farmers today that would have an immense impact on emissions while being economically neutral or even beneficial. Sustainable and low emission farming techniques such as silvopasture, multistrata agroforestry, managed grazing, regenerative agriculture, aquaculture, farmland restoration, are all available today and can reduce emissions while being economically positive within agriculture. I’ll cover two of these techniques, and if you’d like to read more I highly recommend the Food, Agriculture, and Land Use section of Drawdown.
Improved Rice Cultivation: Rice provides a full one-fifth of calories consumed worldwide, more than wheat or corn, and is the essential staple in the daily diet of 3 billion people, many of them poor and food insecure. As highlighted in the chart above, rice cultivation represents 10% of greenhouse gas emissions in agriculture. A System of Rice Intensification (SRI) can help lower emissions and raise yields and income for farmers who implement it. SRI is now practiced by 4 million to 5 million farmers around the world, especially in Asia.
The process, at a high level, is as follows: A) Plant seeds earlier (8-10 days out rather than 3 weeks) with slightly more space to soak up the sunshine and grow roots. B) Use purposeful, intermittent watering, rather than continuous flooding. It’s favorable to soil microbes and root systems that like to breathe while disrupting the waterlogged conditions that methane-producing microbes favor. Research shows mid-season drainage alone reduces methane emissions by 35-70%. C) Use a rotating hoe and aerate the soil to handle weeds that come in the absence of flooding. Applying organic compost also helps enhance soil fertility and carbon sequestration.
It all adds up to creating the ideal environment for rice to grow, creating plants that are larger and healthier, with stronger root systems, aided by more abundant, thriving soil microorganisms. Yields are 50 to 100% higher than conventional rice production, seed use drops by 80 to 90%, and water inputs drop by 25 to 50%! All of this while reducing methane emissions dramatically.4
Silvopasture: Silvopasture is the integration of trees and pasture into a single system for raising livestock. Rather than seeing trees as a weed to be removed, silvopasture integrates them into a sustainable and symbiotic system. Pastures that are laced with trees sequester five to ten times as much carbon as those of the same size that are treeless.
Aside from sequestering more carbon, there are demonstrable financial benefits for farmers who adopt silvopasture, coming from the fact that the livestock yield on a silvopasture plot is higher and a diversity of crops can be grown – from trees to nuts, fruit, mushrooms, and maple syrup – that come of age and generate income on different time horizons (some regularly and short-term, others at longer intervals). This allows farmers to mitigate weather events by diversifying their crop financial risk.
Yields vary depending on the silvopasture system employed, but they regularly surpass that of a comparable grass-only pasture by 5-10%. Silvopasture can also cut farmers’ costs by reducing the need for feed, fertilizer, and herbicides. Because the integration of trees into grazing lands enhances soil fertility and moisture, farmers find themselves with healthier, more productive land over time.5
As you may not be a farmer yourself, the specifics are less important than the fact that there are many farming techniques available to reduce emissions while increasing yields.
Business model innovation
Though the advantages of SRI, silvopasture, and other techniques with climate and economic benefits are clear, its growth has been limited by both cultural and economic factors. For example, there is an outdated belief held by many in farming that trees and pastures are not compatible. It’s important we invest in educating farmers on the ground and share the benefits of this science-driven agriculture.
An even more fundamental reason for the lack of adoption comes down to economics: while it might make them money in the long term, shifting farmland to new uses requires a lot of upfront capital that people do not want to spend. In Colombia, for example, farmers look at an investment of $400-800 per acre for silvopasture as a steep short-term expense.6 Much like power purchase agreements, pioneered by Jigar Shah in solar energy, this is where business model innovation can have an enormous impact.
Power purchase agreements came about in the early 2000s because organizations wanted to adopt solar energy (for the environment but mainly because it was cheaper than alternatives) but resisted because they’d have to pay millions of dollars upfront to install a new solar energy system, money they’d prefer to invest into the business. Under a project finance business model, companies like Generate Capital make the upfront investment to purchase and own the solar assets and then charge companies for energy as they use it – energy as a service – defined by a contract set in place before the solar unit was developed. This changed what was traditionally a capital expenditure into an operating expenditure for companies, unlocking the proliferation of solar as it allowed companies to spare upfront costs while paying less for energy over time. This business model innovation has created an entire industry worth 100s of billions of dollars and immense climate profits. There are literally trillions of dollars that can be unlocked when applying this sort of thinking to other fields like agriculture.
Reducing Emissions From Meat
Between the land, food, excrement decomposition, and processing required to husband animals, not to mention the immense amount of methane produced by ruminant animals such as cows and sheep through enteric fermentation, emissions from meat represent ~14.5% of global emissions! That number is expected to grow as our population grows and the standard of living rises globally.7 A shift in diet to a primarily vegetable-based diet would have major benefits for the climate, though there are obvious shortfalls relying on cultural and habitual change.
Plant-based alternative burgers, such as the ones from Impossible Foods and Beyond Meat, have emerged; while they have some way to go on taste (and they are improving), the economics do work well. There is also progress being made in lab-grown meat, however, the costs are still too high to scale; innovation is needed both to lower costs and to make a delectable diversity of alternative meat options.
While the ideal climate scenarios would entail a reduction in meat consumption and a swift transition to plant and lab-grown meat, that requires a change in cultural norms, which will be difficult to achieve.
Some progress is being made on ways to reduce methane emissions from ruminant animals. One such innovation started with a discovery that when cows are fed the kelp Taxiformis Asparagopsis their emissions are reduced by ~90%! Scientists are currently looking for ways to scale and distribute bromoform, the active ingredient in Taxiformis Asparagopsis, though we still have ways to go.
Food Waste. While the chart at the top of this article is useful in helping us understand where emissions come from within farming, it does not share the whole picture. The reason for that is there are a lot of emissions related to food that are separate but tied to agriculture. Worldwide 20% of food is wasted (40% in the United States!), representing 6% of global emissions.8 Part of this waste is due to consumption habits, but the major contributor, about ⅔ of food waste, is due to the waste created throughout the ‘cold chain’. The cold chain is a not well-known but crucial network of refrigerant warehouses, distributors, and edge modules that brings food (and many other things) from farm to table. Technologies like the ones developed by Therma exist to help reduce food waste in the cold chain; these technologies need to become ubiquitous as they are a positive for climate and save businesses money as wasted food means wasted revenue.
Synthetic fertilizer, developed in the 1960s and 70s, has been a key factor in society’s ability to sustain its growth; surprisingly, it is estimated that the world’s population would be 40-50% smaller than it is today if not for synthetic fertilizer!
Fertilizer provides plants with essential nutrients such as phosphorus, potassium, and nitrogen. Nitrogen is very important, as it helps plants in the photosynthesis process; without it, plants wouldn’t grow. Coincidentally, nitrogen is also very bad for climate change. On average, less than half of the nitrogen applied to soil globally ends up being used by crops; the rest runs off into ground or surface waters, causing pollution, or escapes into the air and forms nitrous oxide (which has 265x global warming potential than carbon dioxide).
There are also the emissions that come from synthesizing ammonia used in fertilizer. Fertilizers are expected to represent 1.7 billion tons of greenhouse gas emissions by 2050. Moving to a clean synthesizing process would raise costs by more than 20% today, so innovation is still needed here to make it cost-competitive. Then there is still the problem of applying it in a way that is not wasted, resulting in extra nitrous oxide emissions.
While there is no equivalent of carbon capture for nitrous oxide, there is work being done to genetically modify a) plants that can recruit bacteria that produce nitrogen they need, and b) bacteria that produce nitrogen for plants in a way that’s more judicious to the environment.9 While on the topic of genetic modification, there are also genetically modified plants that have been developed to be more tolerant of varying climate conditions, which will be of use as temperatures and water levels rise and fall due to climate change; more on that in the discussion on mitigation strategies.
Note on deforestation, reforestation, and planting trees and plants.
Deforestation and other uses of land add a net 1.6 billion tons of carbon dioxide to the atmosphere a year and destroy essential wildlife habitats.10 This is a major problem we’ll cover in the section on what governments can do to make a difference. Additionally, there is a long dialogue taking place around the importance of reforestation, as well as planting trees and other plants for use in sequestering capture. We’ll cover this more in detail in the section on carbon capture.
While there’s a lot of scientific and technical innovation that needs to be done when it comes to things like enteric fermentation and fertilizers, there are many tools at our disposal today that can help us draw down and limit emissions in agriculture. Through business models that align incentives, utilizing known scientific and engineering methods, we can create a win-win for all involved. One of the biggest challenges when it comes to agriculture will be overcoming human systems - business models, stale knowledge, cultural and habitual barriers, government incentives, and so on. While there’s a long way to go, there is a lot we can do to change how we use the land and preserve the life on this beautiful planet we call home.
Happy Earth Day
Gates, Bill. How to Avoid a Climate Disaster (p. 112).
Hawken, Paul. Drawdown (p. 48-49).
Hawken, Paul. Drawdown (p. 49-51).
Hawken, Paul. Drawdown (p. 50).
Gates, Bill. How to Avoid a Climate Disaster (p. 118).
Gates, Bill. How to Avoid a Climate Disaster (p. 121-125).
Gates, Bill. How to Avoid a Climate Disaster (p. 112).