Almost 84 percent of Southeast Asia’s planned and existing fossil fuel power plants are incompatible with future scenarios that avoid catastrophic damage from climate change, according a new study from the University of Oxford.

The report, which comes on the heels of a major United Nations-backed study of the impacts of global temperatures rising 1.5 degrees Celsius (2.7 Fahrenheit), is based on analysis of the amount of carbon expected to be emitted over the lifespan of the plants. Those estimates...