The following is adapted from State of Green Business 2018, published by GreenBiz in partnership with Trucost.

Biology, the scientific study of life at every level, shows how organisms — from single cells to human bodies — stay diverse and productive over time. We study biology in part to better understand our bodies, our resources and the potential threats to our environment. Oversimplified, biology plus chemistry plus physics makes all life possible.

Now, add to that equation: engineering.

That's the mashup behind synthetic biology, a relatively new scientific field. Its roots trace to the early 1960s, but it's been only since the 1990s, with the advent of the genomics revolution and the rise of systems biology, that scientists developed a rigorous engineering discipline to create, control and program cellular behavior.

Today, synthetic biology — "synbio," for short — is rapidly growing, with great promise for addressing a wide range of sustainability issues, including how we power and feed our world, and how we design and create the materials we use to make things. It stands to revolutionize agriculture, energy production, water filtration and a variety of resource-intensive industrial processes.

"The big issues facing humanity can be solved with biology," said Craig Venter, legendary biotechnologist and entrepreneur and founder of the company Synthetic Genomics. "We need to feed 9 to 10 billion people and provide energy and clean, potable water. We're currently destroying our environment at an increasing pace. Biology stands to become the No. 1 sustainable energy source in history."

We need to feed 9 to 10 billion people and provide energy and clean, potable water. We're currently destroying our environment at an increasing pace.

It's also become a significant source of controversy, particularly among environmentalists, who view synthetic biology as essentially "playing God" with life's genetic instructions, potentially causing great harm to nature's biological and ecological systems. References to "Jurassic Park" permeate some of the more critical literature on the field. In 2010, a U.S. Presidential Commission for the Study of Bioethical Issues heralded synbio as a significant breakthrough, but offered 18 recommendations aimed at creating "an ongoing process of prudent vigilance that carefully monitors, identifies and mitigates potential and realized harms over time."

Not that the U.S. government is standing on the sidelines. DARPA, the Defense Department R&D lab that helped create everything from the internet to Siri, has ramped up its synbio funding, including for designing and manufacturing DNA. Meanwhile, federal agencies are angling for which, if any, agency needs to oversee this technology. The U.S. Food and Drug Administration, Department of Agriculture and Environmental Protection Agency might all lay claim to a product made using synthetic biology, depending on the method of production and its intended use. Similar conversations are happening in governments around the world.

Much of synbio's greatest potential goes right to the heart of sustainability's biggest challenges. Let's start with food. Hacking the biological code is making it possible to produce milk without cows, eggs without chickens and a variety of meats without animals of any kind.

A number of startups have staked a claim on plant-based protein using synbio processes. Some, such as Impossible Foods and Beyond Meat, are already on supermarket shelves and restaurant menus, at least in some places, touting burgers so real that they "bleed." They use a genetically modified yeast concoction to produce heme, responsible for meat's characteristic taste and aroma. Creating heme in the lab uses a process similar to brewing beer.

Some synbio startups are already on supermarket shelves and restaurant menus touting burgers so real that they 'bleed.'

Genetically modifying yeast is at the heart of several such innovations, as it is easy to manipulate, quick to grow and difficult to contaminate with microbes. That means removing some public health concerns associated with meat production, such as pathogens and salmonella.

Perfect Day Foods is producing milk and other dairy products using a specially designed yeast the company has dubbed Buttercup. Clara Foods is whipping up chicken-free egg whites. Sugarlogix is in the early stages of brewing something a bit different: breast milk. Still another startup, NotCompany, based in Chile, aims to disrupt the food industry with software called Giuseppe, which combines AI and machine learning to discover what's in food — nutrition and sustainability, but also mouthfeel, flavor and color — and recreate it in a lab with a vegan twist. In a related, non-edible realm, Modern Meadow is harnessing design, biology and engineering to produce biofabricated sustainable leather.

It's not just startups. Big chemistry has been all over synbio for years. For example, DuPont, together with Goodyear Tire & Rubber, is developing a reliable, high-efficiency, fermentation-based process for the BioIsoprene monomer — a substitute for rubber — and synthetic biology has played an important role. Big companies are also investing in synbio startups: Exxon, BP and Novartis are backing Synthetic Genomics, for example, and Amyris Biotechnologies, which tweaked yeast to spit out a substance that makes fuels, plastics, detergents and fragrances, has partners such as Shell and Mercedes as well as Al Gore and Bill Gates.

For these innovators, a big prize awaits success: About 160 million steers, pigs, sheep and chicken were slaughtered in the United States in 2016, and 100 billion eggs were produced. Because livestock production is second only to energy production as a major source of greenhouse gas emissions — not to mention its impact on water pollution and land use — there's a big environmental benefit from these products.

Similarly, synbio has a role to play in upending energy production, particularly for alternatives to petroleum-based fuels that decompose and recycle carbon biomass more efficiently to produce fuels, chemicals and plastics.

Synbio has a role to play in upending energy production, particularly for alternatives to petroleum-based fuels that decompose and recycle carbon biomass more efficiently.

Waste-gas-to-fuel startup LanzaTech is genomically manipulating clostridia, a bacterium that produces energy via anaerobic digestion. The company has partnered with steel mills in Asia to capture emissions from steelmaking, then bubble the gases through fermentation tanks to feed engineered microbes, creating low-cost ethanol and other chemicals. It's become one of the companies to watch in the emerging circular economy.

Agrivida uses synthetic biology to insert a gene that will trigger an enzyme to break down the cell walls of corn stover and other tough biomass materials in order to produce biofuels. Similarly, researchers at the University of Minnesota engineered a "synthetic biopathway" that more efficiently and cost-effectively can turn ag waste into a variety of useful products, from chicken feed to Spandex.

Synbio's holy grail is to design microbes that efficiently gobble up carbon dioxide, carbon monoxide and methane to produce chemicals, turning emissions from industrial processes into revenue streams.

Despite the high expectations, serious questions remain. What are the unintended consequences of synthetic biology? Will consumers accept foods and other goods made with altered genes? After all, synthetic biology builds upon genetic engineering, which after 30 years is still encountering consumer resistance in some parts of the world.

Synthetic biology builds upon genetic engineering, which after 30 years is still encountering consumer resistance in some parts of the world.

Case in point: The sustainably minded detergent brand Ecover faced blowback in 2014, when it said it would use oil produced by engineered algae instead of from palm oil, which has been linked to deforestation, habitat degradation, climate change, animal cruelty and indigenous rights abuses in countries where it is produced. One critic referred to the novel material as "extreme genetic engineering." Ecover ultimately decided not to make the switch.

Still, investors are eyeing synthetic biology innovators, and a small but growing number of venture funds and accelerators are focusing on bringing these companies and products to market. While the numbers are small compared with other tech sectors, funding for synbio startups has tripled over the past five years, to $4 billion, according to research firm CB Insights; in 2016, investments surpassed $1 billion for the first year. Other big-idea organizations — XPRIZE Foundation, Singularity University and Google's X facility among them — see the potential for disruptive breakthroughs in a wide range of fields that stand to improve human and environmental well-being — the very heart of sustainability.