Last weekend, representatives of 195 countries reached a landmark accord in Paris to lower planet-warming greenhouse gas emissions. On Tuesday, local leaders in San Diego committed to making a city-size dent in the problem. With a unanimous City Council vote, San Diego, the country’s eighth-largest city, became the largest American municipality to transition to using 100 percent renewable energy, including wind and solar power. In the wake of the Paris accord, environmental groups hailed the…