Precedents and Goals on Climate Change In accordance with Mexican legal precedents, climate change is the "[v]ariation of the climate directly or indirectly attributed to human activity, which alters the composition of the global atmosphere and adds to the natural variability of the climate observed during comparable periods." In response to climate change, Mexico has implemented and adopted several mitigation and adaptation policies under the precaution, sustainability, co-responsibility and progressivity principles established in the Mexican Constitution, international treaties and environm...