PARIS, France — The Paris Agreement to address climate change, adopted on Saturday, will be remembered as a big step forward and at the same time a frustrating set of compromises and omissions.

The COP21 conference brought every country to the table, they all accepted the science of climate change, and they agreed to work together to do something about it. But some proved more ambitious than others, and the rich countries didn’t come up with enough money to get the best deal possible.

The bottom line is that the agreement gets us far closer to containing climate change than we were two weeks ago, but still far short of where we need to go. In fact, we won’t even know for years what it will accomplish. How much the agreement reduces greenhouse gas emissions, and through that reduces warming, will depend on whether countries meet their targets for curbing emissions and deploying renewable energy and whether they ramp up their ambition in the years ahead. In terms of climate justice, there is even less to cheer. Rich countries like the U.S., Canada, and the European Union upped their pledges for climate finance slightly, but nowhere near enough to compensate for the hugely outsized share of the global carbon budget they have devoured.