John Holdren, the Obama administration's new science advisor, said the administration is discussing radical technologies to combat global warming including extreme geoengineering proposals such as shooting pollution particles into the upper atmosphere to reflect the sun's rays.

A researcher has found that aerosol seeding -- a technique proposed for combatting global warming -- could block part of the sunlight collected by solar panels for heat and electricity -- in some cases by significant amounts -- thereby compromising an important source of green energy.