Forty-seven widely varying technologies can be developed in stages over the next 30 years to reduce greenhouse gas emissions. That's the conclusion of directors of 11 national laboratories of the Department of Energy. They recommend "a vigorous national push" to bolster the 47 technologies. The result, they say, could eliminate hundreds of millions of tons of carbon emissions per year. The report envisions how progress could unfold. The first decade would bring significant advances in energy efficiency technologies--such as in appliances, heating and cooling systems, and transportation. Strides would be made in such near-term practical technologies as electric hybrid vehicles, high-efficiency lighting, super-insulating windows, and passive solar heating and cooling of buildings. The following 10 years would see research-based advances in clean energy technologies. These could include high-efficiency natural gas systems, fuel cells for transportation, microturbines, broad use of biomass fuels, hydrogen-fueled energy systems, and renewable energy, such as solar and wind.