In Oklahoma, seismologists have warned that significant temblors last week could signal a larger, more dangerous earthquake to come in a state where drilling is destabilizing the bedrock. [The Guardian]

Russia’s main stock indexes plummeted on Monday as the drop in oil prices cast a pall over the country’s energy-dependent economy. [The NY Times]

Data compiled from daily reports by the state’s major grid manager indicate that in 2015, solar became the No. 1 source of renewable energy in California. [KQED]