A scientist shapes burger patties at the Impossible Foods headquarters in Redwood City, California. Melia Robinson The world's population is expected to top nine billion people by 2050 — a figure that has some worried there won't be enough resources on the planet to support animal agriculture at that scale.

While Silicon Valley startups like Hampton Creek and Impossible Foods chip away at creating meat-free proteins that could someday feed the masses, an unlikely group of investors has joined forces to bring food industry giants on board.

Seventy-one investors worth a combined $1.9 trillion are working together to put pressure on the world's largest food companies to "future-proof" their supply chains by bringing more meat alternatives to market. Founded in 2015, the FAIRR (Farm Animal Investment Risk and Return) initiative aims to make the food supply chain more sustainable by promoting plant-based foods, while also helping investors cash in on a lucrative new business.

The substitute meat market is expected to climb 8.4% annually over the next three years, reaching $5.2 billion globally by 2020, according to Allied Market Research.

Jeremy Coller, a titan of the private equity industry and founder of FAIRR, tells Business Insider that because members of the coalition make up a large percentage of investors in these grocery chains and food manufacturers, they essentially have the power to say, "We own you." The investors can then steer food companies towards more sustainable supply chains.

FAIRR has produced extensive briefings on the animal agriculture industry, in the hopes of educating shareholders at food giants like McDonald's, Domino's, and Yum! Brands on the environmental and financial gains of diversifying their supply chains.

Animal agriculture takes up about a third of the world's land, and is responsible for 15% of greenhouse gas emissions. AP

In 2016, the group fired off a letter to 16 multinational food companies, asking that they "explore and report back on" efforts to scale back their reliance on animal products.

In a copy of the letter provided to Business Insider, FAIRR writes that large retailers have an important role to play in making meat-free alternatives available and affordable for consumers.

"We warmly welcome the fact that Tesco [a European supermarket chain, named in the copy given to Business Insider] offers a wide range of plant-based and lower-meat options to consumers; however, we believe there is room for further progress to be made," the letter said.

It goes on to make recommendations on how the company can improve, including giving non-animal protein products preferential placement in grocery stores (like in the meat aisle, as opposed to the vegetarian foods section) and making the packaging more attractive.

The letter also encourages companies to invest in "product reformulation," a food and beverage manufacturing term that means swapping some ingredients for better ones, which in this case, means ingredients not sourced from animals. It also suggests spending on consumer education to "raise awareness of the environmental and health benefits of more sustainable diets."

Impossible Foods was founded on the idea that there's a better way to satisfy people who enjoy meat. Melia Robinson/Business Insider

FAIRR targets food companies including Kraft Heinz, Nestle, Unilever, Walmart, and General Mills. As the coalition grows, so will the number of food companies the group goes after.

Coller, who has been a vegetarian since he was 12, is on a mission to wipe out factory farming. (These large industrial operations raise over 99% of farm animals in the US.) He's invested in several plant-based protein startups, including Impossible Foods, Hampton Creek, Clara Foods, and Beyond Meat, which sells burger patties made from pulverized beets in select Whole Foods.

However, Coller avoids talking about animal welfare when he's around investors involved in FAIRR, because he says most are more concerned with the bottom line. With FAIRR, he appeals to investors who look at the meat alternatives market and see an opportunity to pioneer a new multibillion-dollar industry.

"FAIRR is totally about materiality, not morality," Coller says.