Thursday I’m off to attend the UN climate change negotiations in Paris, primarily to highlight California’s effort to achieve a strong subnational agreement on greenhouse gas reductions. The “Under 2 MOU” is an impressive commitment by diverse subnational entities to keep warming to under two degrees Celsius by 2100. It already has 57 signatories, constituting the largest combined GDP in the world.

I’m looking forward to the trip, as I hope to learn a lot and meet people working on climate change all around the globe. But I have to confess, I’ve been a longtime skeptic of the UN process on climate change and am still unsure of what can be meaningfully gained there this time.

If we want to solve climate change, the world needs to do two things: put a meaningful price on carbon and reduce the cost of clean technologies, like solar panels and batteries. As I look to Paris, I wonder what authority the UN and the high-level attendees there have to actually make progress on those two fronts.

In terms of setting a price on carbon, it seems politically impossible that we’d ever have a UN-mandated carbon tax. That price will have to come from nations willing to impose it, and that means votes from members of parliaments and congresses across the globe (or party leaders, if we’re talking dictatorships here). Those decision-making bodies will be hardly represented in Paris, or bound by what comes out of it, as it seems most negotiators are agency heads and their deputies. In other words, President Obama and John Kerry do not have authority to impose a national carbon tax in the United States, they need congressional representatives to vote for it, and they won’t — at least in the current congress.

On the clean technology front, the UN may be better suited to develop a pot of money for rich nations to fund for clean tech. Already we’ve seen Bill Gates and other wealthy people step up for a “clean innovation” fund. So maybe we’ll see some progress there. But again, much of the support for clean technology will come from domestic programs, like the U.S. solar tax credit or California’s energy storage mandate. The people who make those decisions won’t be in attendance or negotiating and won’t have to abide by any resulting agreement.

So is Paris pointless? Well, sure, if we don’t get a good agreement. But if we do, what’s the upside?  For starters, it can’t hurt to have a strong, international political signal that countries everywhere are willing to do something on climate. Maybe that statement will embolden decision-makers in these various countries to follow through on the needed policies, described above. And at a minimum, it could be useful to have information-sharing among the countries and a framework for more aggressive action in future years.  So all of that is reason to support what’s happening in Paris.

I don’t mean to be a Debbie Downer, but I also don’t want the UN process to give everyone a false sense of progress, or distract from the real work that needs to be done. That work is happening now in places like California, Germany, Japan and other progressive states and nations. They need support and action to demonstrate to the world how to reduce emissions and grow the economy. Because ultimately those examples are what will motivate action in other places — not a voluntary international agreement.

I may return from Paris singing a different tune on the negotiations.  But before I go, perhaps in the spirit of Pope Francis, I feel compelled to confess this pessimism.