While not a substitute for cutting greenhouse gas emissions (as both WWF and NRDC remind us), this is potentially a very positive step in reducing air pollution, indoor and outdoor, as well as reducing global warming and glacier melting.
The Climate and Clean Air Coalition to Reduce Short-Lived Climate Pollutants, just announced by Secretary of State Clinton, will be administered by UNEP with the backing of the US, Canada, Sweden, Mexico, Ghana, and Bangladesh. The five-year initiative aims to reduce black carbon soot, methane and hydrofluorocarbons.
Research has shown, in multiple studies, that cutting these air pollutants, which all increased warming but are much shorter lived in the atmosphere than CO2, can slow warming by as much as 0.5°C by 2030. Back in 2010, the EPA said that phasing out HFCs would effectively slow the effects of global warming by a decade.
Technical note: Black carbon soot isn't technically a greenhouse gas like the other pollutants mentioned here, though it does contribute to warming and glacier melting. Rather it's particulate air pollution. It's caused by older diesel engines, industrial processes, and cooking in open air stoves, as is common in many parts of the world. In the latter case the effect is as much a public health concern as it is an issue of global warming, which affects women disproportionately to men, when done indoors without adequate ventilation.
TreeHugger has covered this issue from both a science and health perspective before a number of times, so check out the links at left to get up to speed.