More than 60 countries are aiming to reduce carbon emissions to net-zero by 2050 , according to the United Nations.

The United Nations announced this week that more than 60 countries have said they will try to reduce their net carbon emissions to zero by 2050. But those countries in 2017, accounted for only 11 percent of global emissions — in other words, not a lot.

That’s because the world’s biggest emitters are missing from the list, including the top three: China, the United States, and India. The sizeable emitters on the aspirational net-zero list include Britain, France and Germany. Most of the rest are small countries that have tiny carbon footprints yet are among the worst affected by the ravages of climate change, like the Bahamas, the Maldives, and the Marshall Islands.

How the net-zero goals will be accomplished is unclear. Some countries may bet on technological advances to capture carbon, which would allow them to continue drilling for oil and gas. Others could seek to offset their emissions by buying credits for green projects like tree-planting programs.

Britain is among the very few that have codified the net-zero goal into law. Chile is working on a law that would make its net zero goal mandatory. Finland has said it will aim for carbon neutrality by 2035, while Norway is aiming for neutrality by 2030.

The United Nations trumpeted the announcement, but the criteria for being included on the list are vague. Countries can either have “plans to achieve net zero CO2 emissions by 2050” or have it as “a long-term national goal.” Others can be on the list simply by talking about “a long-term strategy for climate-neutrality in line with the Paris Agreement,” which is the 2015 global accord designed to try to avoid the worst effects of climate change.

Not included in the chart above are the efforts of some state and local governments. Australia hasn’t signed on to a net-zero goal, but four of its states have. Within the United States, New York and California are racing to get to net zero by 2050.

California, whose economic output surpassed Britain last year, accounted for 1 percent of global emissions in 2017, according to an analysis by Climate Action Tracker, a group that evaluates global climate pledges.