The chart compares a country’s social cost of carbon to its share of global emissions. The radiating lines show the ratios of a country’s share of global emissions to its share of the damages.

The United States is almost balanced, with its high social cost of carbon roughly proportional to how much carbon dioxide it emits. But India pumps out just 6 percent of global greenhouse gases and will bear more than 20 percent of the global economic burden from climate change. In other words, India faces almost quadruple the damages of global warming compared to its contribution to the problem. Zoom in further and you’ll notice that many of the wealthiest countries in the world stand to bear the lowest costs of climate change.

This is part of why the global social cost of carbon, $417 per ton, is so much higher than it is for any individual country. The costs of climate change are greater than the sum of their parts. Yet it also shows that many of the wealthiest countries, which contributed the most greenhouse gases, stand to be the best insulated from its costs.

That makes climate change a global justice concern. In limiting global warming, wealthy countries face a moral imperative to look beyond their borders and GDPs, pushing even harder to cut their own emissions. The social costs of carbon also show why climate change really has to be tackled as a global problem rather than by individual nations. But as long as countries like Russia, the United Kingdom, and Germany face little financial fallout, that policy case becomes much harder to make.

via Social cost of carbon: why climate change is a global injustice – Vox