Climate change threatens to undermine the last 50 years in economic development and progress in global public health unless leaders from every sector work to change dependence on fossil fuels, a new report concluded.The report, published Monday in The Lancet, Britain’s medical journal, is considered a major study on climate change and its effect on public health. The study’s authors build on a report released in 2009 and press for major changes over the next five years, including the rapid phase-out of the 2,200 coal-fired plants currently proposed globally.Otherwise, the authors warn of more heat waves, floods, drought and the spread of disease, lack of food, displacement and mental health issues, all because of dependence on fossil fuels.“Tackling climate change could be the greatest global health opportunity of this century,” according to the authors. “Many mitigation and adaptation responses to climate change are ‘no-regret’ options, which lead to direct reductions in the burden of ill health, enhance community resilience, alleviate poverty and address global inequity.”Local health leaders who gathered Tuesday at downtown Los Angeles’ California Endowment headquarters pledged their commitment to work together and agreed with the report’s recommendations. Better access to more public transportation, bike paths, water conservation and other efforts need to continue to move forward in Southern California, many said. Those from the American Heart Association, the American Lung Association and various environmental groups called on lawmakers to push for policies that would reduce emissions that poison the air.