Earlier today, the United States and China announced that they would formally ratify the Paris Climate Agreement, a pivotal step toward reducing global greenhouse gas emissions. The announcement comes on the eve of the G20 summit in Hangzhou, China, after weeks of negotiations between the two countries.

In a statement, President Barack Obama noted that the entry of the two countries will "[continue] the momentum of Paris, and should give the rest of the world confidence — whether developed or developing countries — that a low-carbon future is where the world is heading." The move is a rare show of cooperation between the two nations, which have had their share of economic, cybersecurity, and trade disputes in recent years.

The move is a rare show of cooperation between the two nations

In ratifying the agreement, the US and China will work to reduce emissions and pollutants that are linked to rising global temperatures. Their inclusion will help turn the agreement's goals into reality by convincing other nations to ratify it.

In order to take affect, the Paris agreement must be ratified by at least 55 nations representing 55 percent of the world’s emissions, and the ratification by the US and China has been hailed as a breakthrough. Together, the two nations create nearly 38 percent of the world’s emissions. So far, 180 countries have signed the agreement, while 26 have ratified it, accounting for a total of 39.06 percent of the world's emissions.

The Obama administration has implemented a number of steps to help reduce US emissions in the coming years, which include tax breaks for renewable energy sources and a pause on new coal leases. However, US negotiators ensured that the individual targets for each country are not legally binding, which would require congressional approval, which has drawn criticism from European Union nations and environmentalists.