GENEVA — The World Meteorlogical Organization says that preventive action cannot avert natural disasters such as the wildfires raging across Los Angeles, but that it can help save lives and mitigate loss of property. “Land management and prevention, regular clearing of underbrush play a key role in fire management, and evacuation plans are important in saving lives,” the WMO said Friday. “These are all part of effective early warning systems.” In a briefing to journalists in Geneva, Claire Nullis, a WMO spokesperson, stressed the importance of preparing adequate evacuation plans and early warning systems to prevent some of the worst