Pope Francis has expressed his support for another liberal cause.

The pontiff was photographed Monday with environmental activists holding T-shirts with anti-fracking slogans during a meeting at the Vatican.

The pope met with a group of Argentine activists to discuss hydraulic fracturing, a method used to extract gas, petroleum and other underground natural resources that contaminates ground water and creates other environmental hazards.

The activists said Pope Francis told then he was preparing an encyclical -- a letter that addresses Catholic teachings – about nature, humans and environmental pollution.

The new pope has upset conservatives with his open-minded comments on social issues, although most American Catholics say they agree with him.

[Image via Agence France-Presse]