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How Soon Will the Paris Climate Agreement Become Law?

Figure it out yourself with a fun, clickable map.

By Francie Diep


(Illustration: David Vogin)

At a landmark summit in Paris last year, nearly 200 countries adopted an agreement to cut their greenhouse gas emissions with the goal of dramatically reducing the severest effects of global warming. The agreement took weeks (some would say years) of negotiation, but it was just a first step. Now, each country must sign, and later ratify, the Paris Agreement. The signing begins next week in New York.

At every stage, there’s the danger of countries dropping out. If the signing and ratifying isn’t finished before the next United States president takes office and a Republican is elected, for example, the U.S. may never ratify. After all, the two leading Republican presidential candidates, Donald Trump and Ted Cruz, both deny the reality of man-made climate change.

For the Paris Agreement to go into effect, at least 55 countries, representing at least 55 percent of the world’s carbon emissions, must ratify it.

Without enough signees, the Paris Agreement doesn’t go into effect at all. So what will it take for the Paris Agreement to enter into force?

The World Resources Institute has created an interactive tool to answer this question. For the Paris Agreement to go into effect, at least 55 countries, representing at least 55 percent of the world’s carbon emissions, must ratify it. These requirements mean the final mix must include at least one top emitter, plus numerous lesser ones. Let’s look at the breakdown.

If the Paris Agreement hinged only on emissions—requiring only that 55 percent of global greenhouse gas emissions be represented—it wouldn’t need many signees. In fact, it would take just seven of the top emitters, including some of the world’s most powerful countries, to hit the 55 percent mark, even if everyone else reneged on their pledges. See the map here:


(Map: World Resources Institute)

At the same time, top emitters can’t bow out: Even if all 191 other pledged countries ratified the Paris Agreement, excluding the top four emitters — China; the U.S.; the European Union, which will ratify as a bloc; and Russia — the combined signatories wouldn’t add up to 55 percent of global emissions. See the map here:


(Map: World Resources Institute)

Thus, the Paris Agreement depends on a diversity of nations, from the industrialized and developing worlds alike.

For now, Switzerland and four island nations — Fiji, Palau, the Marshall Islands, and the Maldives, all four among the most vulnerable to climate change — have already ratified the Paris Agreement domestically, WRI reports. Once representatives from these countries attend the signing ceremony in New York, they’ll be signed and ratified.

Should other climate-vulnerable nations join them, we may easily reach the 55-country mark. The challenge, then, could be pushing industrialized nations to make good on the promises they celebrated in Paris.