Profit-driven corporations are joining ranks with ecological activists in reducing harmful impacts on the environment in an effort to save life on Earth, a Vanderbilt University law professor told The Rotary Club of McMinnville on Thursday.Michael P. Vandenbergh, who directs the Climate Change Research Network at Vanderbilt, said global tech giants like Apple and Facebook, as well as retail behemoths Walmart and Target, see profit potential in adapting newer, greener processes and practices. Apple, for instance, is building $2 billion in renewable energy facilities in China to power its electronics producers as an alternative to building coal-burning, carbon-polluting plants.Walmart is using its leverage with its worldwide suppliers to enforce more sustainable manufacturing methods with huge reductions in the use of toxic and hazardous chemicals. It was a volunteer organization — the Environmental Defense Fund — and not government that pressed Walmart to agree to reduce its carbon dioxide emission by 20 million metric tons a year, the speaker noted.Vandenbergh, who served in the mid-1990s as chief of staff at the Environmental Protection Agency (EPA), warned that continued “business as usual” would bring the world to “the tipping point” where action become pointless.