Greenpeace Mexico v. Secretary of the Environment of the Government of the State of Mexico

In 2019, Greenpeace Mexico filed an Amparo lawsuit against the Program for Attention to Atmospheric Environmental Contingencies in the Metropolitan Zone of the Toluca Valley and the Metropolitan Zone of Santiago Tianguistenco (“Program”), issued by the Secretary of the Environment of the Government of the State of Mexico, arguing that it violates the human right to a healthy environment by failing to comply with Mexican Official Standards NOM-020-SSA1-2014 “Environmental Health. Permissible limit value for the concentration of ozone (O3) in ambient air and criteria for its evaluation”, and NOM-025-SSA1-2014 ”Environmental health. Permissible limit values for the concentration of PM10 and PM2.5 particles in ambient air and criteria for its evaluation”, and with the guidelines of the World Health Organization (WHO) since it establishes more lenient values of ozone and PM10 and PM2.5, to declare the preventive phase and the environmental contingency phase due to pollution in the area. The District Court granted the requested ordering the Secretary to issue an opinion tending to compare the values contained in the Program in contrast to NOM-020-SSA1-2014 and NOM-025-SSA1-2014, as well as the WHO guidelines. The purpose of this opinion would be “to establish whether or not such values comply with the parameters to decide whether the air quality is good or bad, as well as to establish preventive measures to control and reduce pollutants”. Furthermore, the Court determined that in the event that the Program did not comply with the referred standards, the Secretary should “send the opinion to the competent authority so that the adequacy of the claimed agreement to preserve the environment may be assessed”. The plaintiff appealed the judgment, and the Appellate Collegiate Court modified the District Court’s judgment, ordering the Secretary to issue a new Program, or modifies the values established in the Program, complying with the NOM-020-SSA1-2014 and NOM-025-SSA1-2014 standards and in compliance with the Paris Agreement targets.