Climate change is full of impenetrable acronyms. And here’s another. INDCs, or Intended Nationally Determined Contributions. It’s a less-than-catchy name, but key to understanding the next stage of the global deal on climate change.

Simply put, INDCs are the pledges countries will put forward early next year saying what they plan to do about climate change. We expect to see the bulk of them by the end of March, with a few more possibly following before May, and they will form the basis for the Paris talks in December 2015.

Each INDC will outline the steps countries plan to make to reduce emissions. They might also address adaptation plans, and the support they need from—or will provide—other countries. The World Resources Institute stress that a good INDC should be ambitious, leading to a fair degree of transformation in carbon-intensive sectors and industry. They also call for transparency — so that the level of ambition can be reviewed — and a sense of equity.

All this reflects a shift towards a more bottom-up approach to global climate policy. Rather than attempt to impose an apparently more top-down agreement based on scientific reports, the idea is to allow the countries themselves to state what they are currently willing to offer.

If you think that sounds like a bit of a scary cop-out, where countries can just say they won’t do much, that’d be understandable. But it is still routed in some sense of collective agreement to keep global warming to a globally agreed idea of “safe” (the infamous idea of a two degrees limit). There’s a lot, potentially, to review in the INDCs, both formally and informally. Policy-makers and activists will want to ensure everyone’s doing their fair share, and there are various fights to be had to keep collective ambition high enough to avoid too much catastrophe.

Supporters of the approach see it as realistic and pragmatic. Climate negotiations are a complex business. Environmental leaders at the various big climate talks can offer lofty rhetoric, even make strong demands, but any country signing up to a global agreement will need buy-in from a wide range of domestic actors, and be limited by a range of local economic, geographic, political and cultural factors. If we start from those, so the argument goes, we can gradually build the global system we need.

Still, there are valid reasons to be sceptical about INDCs. The word ‘pragmatism’ can be a euphemism for simple conservatism, and the idea of ‘bottom-up’ can be applied to a range of rhetorical ends (often the particular bottoms in question are quite privileged ones). Keeping countries pledges as ambitious as WRI and others want to see will take some work.

We can expect the bulk of NDCs submissions by the end of March, with some possibly coming later, by the end of May. Following this, there will be an assessment phase to review and possibly adjust them before the COP 21 Paris Climate Summit. As a result, it may be that the Paris deal looks a bit weak but it is hoped an INDC-based system will be one we can constructively build on, avoiding the sense of failure that followed COP 15 in Copenhagen in 2009.