Although there are many options for reducing energy-related CO₂ emissions, some energy services entail emissions that are much more difficult to eliminate. We review technological opportunities and barriers for eliminating and/or managing difficult-to-decarbonize services, and critical areas for further research, development, demonstration and deployment.

China's emissions decreased between 2013-2016. Our analysis shows the decline was largely due to changes in industrial structure and a decline in the share of coal for energy production. Decreases may persist if nascent industrial and energy system transitions continue.

We present new, city-level estimates of CO₂ emissions for 182 Chinese cities, decomposed into 17 different fossil fuels, 46 socioeconomic sectors, and 7 industrial processes, and examine three scenarios of technological progress to show that large reductions (up to 31%) are possible by updating a disproportionately small fraction of existing infrastructure.

"South-South" trade among developing countries is increasing, and helping to reduce China’s emissions by shifting energy-intensive production to less developed regions. But this may make climate mitigation more challenging; emissions are spread among more and less-developed countries.

Analysts and markets have struggled to predict a number of phenomena in U.S. energy markets over the last decade or so, such as the rise of natural gas. I explain new research that shows this may be a result of the industry--and consequently the market--becoming increasingly volatile.

Analysis of hourly weather data shows that meeting >80% of U.S. electricity demand with only solar and wind would require days' or weeks' worth of energy storage--even assuming a continental-scale transmission grid. Today this would be very costly.