The Environmental Protection Agency's "Clean Power Plan" calls for a 32 percent reduction in CO2 emissions by electric power plants by 2030 from 2005 levels.
A group of 25 US states, most of them led by Republican governors, challenged the program before the Supreme Court which by a 5-4 vote put it on hold until an appeals court can
rule on the arguments.
Yesterday, Google, Apple, Microsoft and Amazon filed a brief with the DC Circuit court in support of the program, noting that collectively they are among the biggest US consumers of electricity.
The administration's plan "will help address climate change by reinforcing current trends that are making renewable energy supplies more robust, more reliable and more affordable," the brief said.
The tech giants noted their own efforts to limit the impact of their activities on the environment, in particular by turning toward renewable energy sources for their power needs.

They said the program would help them "power their operations in ways consistent with their environmental commitments and business needs."
"With the plan in place, growth in renewable energy will continue, as electricity generators and sellers will have even more reasons to work with significant purchasers... to develop new approaches that support renewable energy," it said.