Which problem area was added most recently to the global environment facilities mandate?

The problem area of persistent organic pollutants was the most recent addition to the mandate of the Global Environment Facility (GEF). This recognized the global significance of these pollutants, which are often hazardous substances that persist in the environment, bioaccumulate in the food chain, and pose serious risks to human health and the ecosystem. By integrating this issue into GEF's focus areas, it underscored the commitment to addressing not just immediate environmental concerns but also those pollutants that have long-term effects across borders.

The other options, while significant environmental challenges, were established areas of concern within the GEF's mandate prior to the inclusion of persistent organic pollutants. Long-range transboundary air pollution, climate change, and biological diversity loss have all been integral to international environmental agreements and efforts for a longer duration. The recent recognition of persistent organic pollutants reflects an evolving understanding of global environmental issues and the necessity for targeted interventions in combating these particularly harmful substances.