Negotiators heading to Lima for the annual U.N. climate summit face a certain paradox. There are encouraging signs of growing momentum toward a new global climate deal late next year in Paris. Yet over the next two weeks in Lima, the negotiators may make only modest progress at best.

There are good reasons to be hopeful.

First, recent events and announcements have strengthened confidence in prospects for Paris. These include the U.N. leaders summit in New York, nearly $10 billion in pledges to the new Green Climate Fund, Europe’s decision on a 2030 emissions goal, and the joint announcement by the U.S. and China of their post-2020 targets.

Second, the negotiations throughout this year have been notably civil and substantive. Wide gulfs remain, but rather than succumbing to procedural fights, parties have been putting forward and constructively debating concrete ideas for the Paris agreement.

Third, behind the scenes, there is a fair degree of convergence among key countries on the broad outlines of a Paris deal. This is reflected in a recent report from the co-chairs of Toward 2015, an informal dialogue among officials from 20+ key countries organized by C2ES.

All in all, with Paris still a year away, there is stronger alignment among major countries, both politically and substantively, than there was at any time leading up to the infamous Copenhagen summit five years ago.

With this sense of gathering momentum, one can certainly hope for good progress in Lima at COP 20 – the 20th Conference of the Parties to the UN Framework Convention on Climate Change (UNFCCC). Nevertheless, given the ingrained dynamics (see below) of the climate negotiations, we’re unlikely to see fundamental breakthroughs.

That’s probably OK. Lima is a stage-setting COP. Its job is to lay a smooth path for the final year of this four-year round of negotiations culminating in Paris. To do that, the COP needs to produce two outcomes.

The first is a formal COP decision spelling out how countries should present their “intended nationally determined contributions” to the Paris agreement (expected early next year) and the process parties will use to look over those numbers ahead of Paris. This will require some tough compromises, in particular on the scope of parties’ intended contributions (mitigation only, or adaptation and finance too). But it should be doable. (Read the draft decision floated by the talks’ co-chairs.)

The second important outcome is a document outlining the “elements for a draft negotiating text” of the Paris agreement.  (The actual draft, which will then become the basis for further negotiation, isn’t due until six months ahead of Paris.) This pre-draft, or very first rough cut, will indicate where parties are beginning to converge on the content, and possibly the form, of the Paris agreement, and where they remain far apart. (Read the “non-paper” from the co-chairs that will be the starting point in Lima.)

Apart from genuine substantive differences, the negotiating dynamics will likely limit the progress that can be made in sketching out the Paris agreement.

There’s a strong tendency in climate negotiations to hold onto issues until the final moment, and in this case, the final moment will be Paris. Parties will want their pet issues reflected in the text coming out of Lima, even if there’s virtually no chance of them making the final cut next year. And even if there is broad agreement in some areas, the UNFCCC typically operates by the principle that nothing is agreed until everything is agreed. So we may strain in Lima to discern signs of genuine progress, and can expect a very full negotiating agenda for the coming year.

Perhaps what’s most important is that Lima avoid the procedural showdowns that have gummed up past conferences, and that parties leave feeling confident about the negotiating process itself. If they are to make real substantive progress through the course of next year, and not leave absolutely everything to Paris, the parties need to feel that the process is fair, open and inclusive.

The signs are good heading into Lima. The road from Lima to Paris will not be an easy one. But if we continue seeing the kind of leadership among major countries that’s emerged in recent weeks, we’ll have a good shot at a good deal in Paris – a durable agreement that gets all the major players on board, provides strong accountability so we know if countries are fulfilling their commitments, and works to build ambition over time.