SINGAPORE — Recent developments in curbing high levels of forest loss around the world, particularly in the tropics, are promising. They are significant because deforestation, including the clearing of trees from peat swamps in Southeast Asia, is the biggest source of global warming emissions from human activity after fossil fuel burning.

Indonesia has the eighth-largest forest area on the planet and half the global total of tropical peatland. It is the world's leading emitter of carbon dioxide (CO2) and other greenhouse gases from deforestation.

So Indonesia's announcement last month that starting next January it will place a two-year moratorium on new permits to clear natural forests and peatlands is a potentially important advance in a program backed by Japan to help developing countries protect forests and slow global warming.