The big question about the Paris Agreement is whether it can act as a powerful catalyst for radical change in a range of complex social, economic and political systems. 

The legal status of the Paris Agreement is important here. Critics have pointed out that it does not have binding targets to limit greenhouse gas (GHG) emissions. The politics of achieving that were simply impossible.  

What is binding in Paris is a set of provisions that oblige countries to have a plan, to regularly update the plan to make it stronger, and to communicate with citizens about how it is doing. This process has to be underpinned by credible and consistent data, and both the Paris Agreement text and the COP decision text (which outlines the measures to be taken before 2020) deal carefully and extensively with this. 

All of this will provide a framework against which accountability dynamics can work through reputational incentives, peer pressure, policy advocacy and activist litigation. The example of the successful case brought to oblige the Dutch government to raise its game on climate change mitigation is surely a taste of things to come.  

Many of the most important things in Paris happened off-stage. One hundred giant, influential global companies committed to achieving 100 per cent renewable power, signalling massively increased corporate demand for renewable energy (though the time-frame for this is vague).

The Mission Innovation initiative announced at Paris commits 20 major economies (including China and the United States) to double public investment in clean energy innovation over five years. The hope that technological breakthroughs in renewable energy and storage could make fossil fuels uncompetitive on price alone is gathering momentum.