The world’s biggest greenhouse gas polluters are poised to adjourn a series of meetings in Italy without any significant breakthroughs between developed and developing nations. Though hardly surprising, the news certainly reaffirms fears that it could be a long slog to Copenhagen.

In this week’s issue of Nature, we take a look at some of the positions and ideas being put on the table by developing nations. The upshot is that many developing countries, recognizing the threats posed by climate change, are doing quite a bit to clean up their economies. Nonetheless, they remain understandably wary of binding requirements that might restrict their ability to lift themselves out of poverty.

Countries like India, China, Brazil and others are focusing on per-capita emissions within a historical context. From this perspective, industrialized nations have pumped far more than their fair share of pollution into the atmosphere, which provides a limited cushion for development powered by fossil fuels. The way China runs the numbers, industrialized nations would have had to stop emitting all together two years ago. Recognizing that it will be virtually impossible to achieve parity under such terms, Bolivia has proposed the concept of a “climate debt,” illustrated in this graph, which is basically the difference between what industrialized nations should be allowed to emit on a cumulative, per-capita basis and what they actually emit.

In other words, industrialized nations can use up more than their fair share of the allowable emissions, but they must pay for it. This transfer of wealth is likely to be the crux of any deal that might be struck this year; developed countries know they are going to have to write checks, but they want assurances that those checks will be put to good use. One solution is to start out with sectoral approaches that guarantee certain types of policy and technology changes, which can reliably be counted on to reduce emissions.

As it happens, a PNAS paper out this week takes a different approach to climate equity by targeting wealthy individuals rather than wealthy nations. Although the end result is similar, their proposal does not cover historic emissions, which are at the heart of the proposals outlined above.

One thing is sure: No agreement can be struck unless the gulf between developed and developing nations is bridged. Barack Obama’s ascension to the White House makes political progress possible in the United States, but politicians in the US and Europe know that slashing emissions in developed countries alone simply cannot solve the problem. Indeed, this is one of the principle arguments being raised against climate legislation that is poised to be taken up in the US Senate. And from this perspective, it’s possible that progress on the international front is just as critical for striking a deal within the US as US participation is at the international level.