Sanders’ email comes on the heels of the Clinton campaign’s February 12th release of a policy promoting new natural-gas extraction and infrastructure. Clinton’s promotion of “safe and responsible natural gas production” (the phrase “safe and responsible” was used five times) was praised by LiUNA, a trade union that had vigorously supported the construction of the Keystone XL pipeline.

“Domestically produced natural gas can play an important role in the transition to a clean energy economy,” Clinton’s policy position states, making no mention of the candidate’s February 4th pledge, caught on camera, to ban the extraction of fossil fuels, including natural gas, from public lands.

The conflict between Sanders and Clinton on natural gas is set to become a point of major political contention, as voters go to the polls next month in states overrun by fracking, including Oklahoma and Texas on March 1, Kansas and Nebraska on March 6, and Ohio on March 15. These states are reeling from the boom and bust of the fracking industry, left with earthquakes, degraded water supplies, and thousands of non-union workers exploited and poisoned by the private fracking companies Clinton’s donors have financed. Fights over natural-gas pipelines and facilities have mobilized activists in dozens of other states.

On a national scale, a growing body of scientific evidence is building that the climate benefits of switching from coal to natural gas were a total mirage, with the catastrophic Porter Ranch methane blowout the most visible and extreme example of a nationwide surge in methane leakage as a result of the domestic fracking boom promoted by the Bush and Obama administrations. Methane is a greenhouse gas that is 80 times more potent than carbon dioxide on a twenty-year timespan.

Read Sanders’ full email: