Wealthy countries that have contributed the most to climate change tend to be most immune to its effects, according to new research, a finding that has implications for the question of who bears responsibility for addressing the crisis.

The study, published in the journal Nature Scientific Reports, shows that more than half of the highest-emitting countries rank among the least vulnerable to climate change and nearly two-thirds of the countries with low or moderate emissions are acutely vulnerable to the effects.

Researchers classified more than 10% of countries as “free riders,” ranking in the top fifth in terms of emissions and the bottom 20% in terms of vulnerability. These countries include the United States, much of Europe and Australia.

On the opposite end, six countries were classified as “forced riders” with relatively low emissions and high vulnerability. Some island countries with low emissions, like Kiribati, could be wiped off the face of the Earth thanks to rising sea levels.

The new study provides a new way for policymakers to quantify inequality when it comes to tackling climate change. Countries around the world have agreed on the principle of “common but differentiated responsibilities” since the early days of climate negotiations in the 1990s. That principle calls on wealthy emitters like the United States to do more to address global warming than poorer countries who emitted less historically.

The issue of differentiated responsibilities played a key role at climate negotiations in December that resulted in the Paris Agreement. Developing countries, many of which are especially vulnerable to rising sea levels, drought and a whole slew of other climate-related issues, demanded developed nations help pay for them to adapt to climate change. The U.S. and other countries committed billions to that effort with that concern in mind.

Another provision, known as loss and damage, calls on developed countries with historically high emissions to help pay for the loss and damage in poor countries caused by climate change (though the agreement falls short of making such payments a legal obligation).

The study, which makes reference to the principle of differentiated responsibilities, underscores the need to implement the Paris Agreement to address the disparity. “To ensure equitable outcomes from climate negotiations, there needs to be a meaningful mobilization of policies,” the study says. “Member states have both an exceptional opportunity and a moral impetus.”

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Write to Justin Worland at justin.worland@time.com.