The paper is about emerging technologies enabled by nanophotonics to combat climate change. We developed and demonstrated 1.) nanocrystal hybridized white light sources and those also embedded with plasmonic metal nanoparticles for the reduction of global energy consumption, 2.) photovoltaic nanocrystal scintillators hybridized on solar cells for the generation of efficient green energy sources, and 3.) photocatalytic nanoparticle and nanocomposite systems for massive environmental decontamination, all to contribute to the reduction of greenhouse gas amount.