The green fields of Texas (Image: Robert Nickelsberg/Getty)

Is Uncle Sam going green at last? US carbon emissions from power stations this year are set to be the lowest for 20 years, as decrepit coal-fired power plants shut and clean wind farms and less-dirty natural gas plants replace them.

And back in 1994, the US economy was only 42 per cent of its current size, adding evidence to the idea that an economy can grow while its emissions go down.

This year’s emissions are expected to be 15.4 per cent below 2005 levels. The startling projection comes from analysts at Bloomberg New Energy Finance. It suggests that the US may now be on course to meet the promise that the Obama administration will take to UN climate negotiations in Paris later this year, to cut total CO 2 emissions by 28 per cent below 2005 levels by 2025.


So what is going on? Most attention has focused on the replacement of coal in conventional power plants by natural gas, much of it from fracking. Burning gas emits only half as much CO 2 as burning coal.

But Greenpeace energy analyst Lauri Myllyvirta says that wind farms have played an even bigger role. She says that since 2007, the rapid growth of wind farms in the US has been responsible for 37 per cent of the cut in power-sector emissions, compared with 30 per cent from the growth of gas, with solar power and efficiency gains making up most of the rest.

And there is much more to come from wind, says William Nelson, an analyst at Bloomberg New Energy Finance. He expects 9 gigawatts more wind generating capacity to be commissioned during 2015, much of it in Texas. It is a wind of change that he calls a giant, permanent step towards decarbonising out entire fleet of power plants.