That's a lot for the industry to get its arms around, and the problem is urgent, said Thomas Gottschalk, executive vice president and general counsel for General Motors.
"We're seeing forecasts of economic and population growth indicating the doubling of the world's car park within 30 years," he said.
"The auto industry can steer society toward sustainable mobility and even sustainable development, mostly by continuing its quest for technological innovation."
DuPont Automotive is trying to lead such innovation, said William Hsu, the supplier's vice president of global technology and the Americas.
Keeping sustainability in mind, the company recently solved an issue at a plant in India.
Water is key to keeping the plant running, Hsu noted, but water in India is scarce and expensive. DuPont could shut down the plant to solve the issue, but that would devastate the local economy.
"That would not be a victory for sustainability," Hsu said.
So DuPont engineers developed a "dry" pump for the plant that eliminated 99.5 percent of its water consumption. The pump reduced DuPont's costs as well.
Susan Cischke, vice president of environmental and safety engineering for Ford Motor Co., said much of the sustainability issue will fall on engineers.
She said the industry should take advantage of "bridge technologies" rather than wait for the perfect solution. She pointed to diesel, hydrogen-powered internal combustion engines, hybrid electric powertrains and drive-by-wire as the bridge technologies.
Bernard Robertson, senior vice president of engineering technologies and regulatory affairs for the Chrysler group, said one of the biggest stumbling blocks in achieving sustainability is that no one has defined the problem specifically, nor what is acceptable in the meantime.
"Are we trying to reduce CO2? Are we trying to reduce imported oil? Are we trying to get rid of oil altogether? Are we trying to achieve zero emissions? It's tempting to say, sure, we want all of the above," Robertson said.
"Well, the only thing that can do that is hydrogen, so let's go to hydrogen," he added. "But it seems as if there's room for some dialogue about what's the hierarchy of needs."
His Big 3 counterparts agreed, saying such direction will help them determine where best to spend their limited budgets.
Robertson also addressed a problem with the supply chain.
"The supply base has got to know what is in their components," he said. "We have to disclose those and eliminate those that are banned substances in Europe.
"As we stand today, we have a large number of suppliers that cannot tell us what's even in their materials. They say, well, that's a Tier 3 or Tier 4 component, and we don't know, and they don't know. That's got to change, and it's got to change quickly."