In the final days of his presidency, Barack Obama is using all the tools he can to leave a lasting impression. He wrote a commentary for the prestigious scientific journal Science arguing that the push toward renewable energy is unstoppable and that it’s a valid strategy for economic growth. Obama notes that carbon dioxide emissions from the U.S. energy sector have fallen by 9.5 percent since he became president in 2008, while the economy has grown by 10 percent. That points to a “decoupling” of growth from greenhouse-gas emissions and contradicts the argument that clean energy requires accepting lower growth rates.