Mexico passed the general law on climate change on 19 April 2012, establishing a new leading global legal best practice to address climate change and transition to a green economy. The new law was only the second climate change law in the world. This working brief by the International Development Law Organisation (IDLO) presents a legal analysis of Mexico's general law on climate change. The analysis confirms that Mexico has firmly established itself as a global leader in setting a strong regulatory framework to move to a low carbon emission economy and many lessons can be learned from Mexico's bold actions.