Pope Francis created quite a stir this week after he posed for photographs holding up anti-fracking t-shirts following a meeting with a group of Argentinian environmental activists to discuss water and fracking issues. The shirts read “No To Fracking” and “Water Is More Precious Than Gold.”

The Pope has already garnered headlines of late for his progressive views on inequality and his view that the Catholic Church has been “obsessed” with certain social issues like abortion, birth control, and gay marriage. Now many are wondering if environmentalism will be next. Pope Francis reportedly told the Argentinian group “he is preparing an encyclical — a letter addressing a part of Catholic doctrine — about nature, humans, and environmental pollution,” Foreign Policy reported.

Among those who met with His Holiness this week is movie director and Argentine politician Fernando ‘Pino’ Solanas, known for his environmental activism and his film “Dirty Gold” about mega-mining. According to Foreign Policy, Solanas is a vocal opponent of an August agreement between the Argentine government and Chevron to develop shale oil and gas, which he calls “the largest environmental disaster in the Amazon.”

Drilling for shale oil and gas often requires the controversial practice of hydraulic fracturing, or fracking, which has generated serious concern in communities around the world for the threat it poses to water supplies. In Argentina, the anti-fracking protests “have grown so fierce that the police have cracked down on thousands of demonstrators with tear gas and rubber bullets,” the New York Times reported.

According to one report from the Pope’s meeting with activists this week, his “concern was ‘clear’ when hearing about the Chevron deal in Argentina and other environmental disputes in the region.”