After two decades of fruitless UN climate gatherings, I finally attended my first one last week and clearly must have broken the stalemate.  Because international negotiators now have a voluntary global commitment [PDF] to keep world temperature rise to possibly less than two degrees centigrade by 2100.  It’s a big victory for the climate movement and for particular world leaders, like President Obama.

Why the agreement now?  It was a confluence of politics and economics.  On the political front, momentum had been building to this conference with everyone from the Pope to Obama to climate activists laying the foundation for broad public support and international cooperation.

On the economic front, the conversation has changed dramatically since 2009’s failure in Copenhagen with the decreasing costs of certain energy technologies.  Specifically, the rapid decline in the price of solar panels, the ongoing investment in and cost decreases of battery technologies (particularly for electric vehicles), and the glut of natural gas, which has helped make the transition away from coal easier.

So what does the agreement portend?  As mentioned, it’s a voluntary commitment without any penalties for countries that fail to comply.  Current business-as-usual policies place the world on about a 3-degree temperature rise by 2100.  So we’ll still need major advancements to meet the terms of the agreement going forward.

As I blogged previously, the decision-makers that really matter weren’t at the Paris conference.  After all, who decides if carbon is taxed or fossil fuel reserves stay in the ground?  It’s the legislators and party bosses in various nations around the globe, and in some cases, it’s subnationals, including local governments with land use authority.  Will they act?  We’ll have to wait and see.

But one promising provision in the agreement is the commitment to greater transparency, in terms of each country’s progress meeting the goals.  Peer pressure can be very effective, and in certain parts of the world, some countries won’t want to be seen as lagging by their neighbors on the climate fight.

So between that peer pressure, and the continued determination of leading climate countries and states like Germany, Norway, and California that is pushing the price declines of clean technology, we have some reason to hope.  Because as celebratory as the conversation has been around the Paris agreement, that is still the position the world is in.