Nature News: This week, in the hallways of a conference in Guiyang, China, Nicola Pirrone—the director of Italy’s CNR-Institute for Atmospheric Pollution Research—will be trying to rustle up more support for a global network to monitor mercury pollution.Such a network would underlie a United Nations Environment Programme (UNEP) treaty to control mercury emissions, which negotiators plan to forge by 2013.Researchers are facing a complex task—how to monitor 2,500 tonnes of mercury every year, more than half of which comes from fossil-fuel power plants—on what may be shoestring budgets.But so far, global monitoring endeavors have been relatively uncoordinated; hundreds of sporadic efforts can include one-time samplings from a ship cruise or aeroplane flight.