A Writ of Kalikasan is a legal remedy under Philippine law that provides protection of one's Constitutional right to a healthy environment, as outlined in Section 16, Article II of the Philippine Constitution, which says the "state shall protect and advance the right of the people to a balanced and healthful ecology in accord with the rhythm and harmony of nature." "Kalikasan" is a Filipino word for "nature".
The writ is comparable to the writ of amparo and the writ of habeas corpus. In contrast, this writ protects one's right for a healthy environment rather than constitutional rights. The writ of kalikasan is "proudly Philippine-made", unlike the other two writs that have roots in European and Latin American law.
Provision for the Writ of Kalikasan was written in 2010 by the Supreme Court of the Philippines under Rule 7 of the Rules of Procedure for Environmental Cases as a Special Civil Action. The Supreme Court under Chief Justice Reynato Puno took the initiative and issued Rules of Procedure for Environmental Case because Section 16, Article II of the Philippines' 1986 Constitution was not a self-executing provision.
The writ of Kalikasan may be sought to deal with environmental damage of such magnitude that it threatens life, health, or property of inhabitants in two or more cities or provinces.
In September 2014, the Philippine Supreme Court ruled unanimously against issuing a writ of kalikasan against the United States Government over the grounding of the USS Guardian on the Tubbataha Reef in 2013.