By Jacob Kastrenakes, The Verge.

Tech giants are gathering in support of the Obama administration's contested plan to shift the US toward clean energy. Apple, Google, Microsoft, and Amazon joined together to file a court brief on Friday, describing their reasons for supporting the Environmental Protection Agency's Clean Power Plan. "Delaying action on climate change will be costly in economic and human terms, while accelerating the transition to a low-carbon economy will produce multiple benefits with regard to sustainable economic growth, public health, resilience to natural disasters, and the health of the global environment," the brief says.

The Clean Power Plan intends to cut carbon pollution 32 percent below 2005 levels by 2030. Accomplishing this will require more than just deployment of renewable energy sources; states will likely have to make their existing coal-fire plants more efficient, or else reduce their usage of them. The rules are currently being challenged in court by 27 states. In February, they were put on hold by the Supreme Court, signaling that the court — as it was then composed — may be leaning in the plaintiffs' direction.