The politicians and diplomats have done what politicians and diplomats do, finding ways to compromise and using creative ambiguity to paper over their differences on climate change.

Granted, they did a better job of it than usual during the climate summit that ended Saturday in Paris. It’s a major achievement to forge a consensus of every government in the world on anything.

So where does the agreement leave the effort to limit the worst effects of climate change? Is the glass a bit more than half full? Or a whole lot worse than half empty?

Here is one lukewarm vote for the former.

It’s true that faced with the need for urgent action, elected representatives reacted in character — that is, much too late. And the compromises necessary to get everyone on board make it very difficult to meet the goal of keeping the increase in Earth’s temperature to 1.5 degrees C. It will be hard enough to keep it to 2 degrees, the threshold at which the worst effects of climate change are likely to kick in. Recall that the plans announced before the conference were estimated to result in a rise of about 2.7 degrees by the end of the century. 

So unless there is a technological miracle or a huge, nasty surprise (the prime candidate being a global economic bust – emissions of greenhouse gases are actually expected to fall slightly this year, probably because China’s economy has weakened), more people are going to get hurt by climate change. That’s a tragedy. Many will be members of groups who are already among the world’s most vulnerable.

The rest of us will muddle through.

Unfortunately, to expect the politicians to have accomplished more is to misunderstand what they really do.

There never was a realistic possibility that national governments would agree to a binding global agreement placing hard limits on their carbon emissions. That would mean ceding control over a vast array of domestic policies, most importantly the economy. And few governments, even those flush with cash, would want to be locked into an agreement requiring a contribution to a fund to help poorer countries develop clean energy and deal with the effects of climate change.

There are binding requirements in the agreement to regularly update national plans to limit emissions, and to report back to the rest of the world on progress. But no requirement to actually meet the targets set by those plans. So the success of the plan largely rests first on countries recognizing that limiting emissions of greenhouse gases is in their own best interest, and second on international peer pressure.

Still, there are some grounds for optimism – if only because the severity of the problem has become so clear to so many.

China and the United States, the world’s top emitters of greenhouse gases, made a major contribution to the Paris agreement with their own deal last year to work in concert on the problem. 

Under Xi Jinping, China appears to be going backward on issues like freedom of expression. But it does appear to have woken up to the danger posed by climate change.

Look at these interactive maps published last week by the New York Times, showing how much of three coastal cities — Shanghai included — probably would be under water if global temperatures continue to rise. China also plans to develop a cap-and-trade system for certain heavy industries. 

In the U.S., President Obama is intent on making progress on climate change a major part of his legacy. He is getting around staunch opposition from Republicans by crafting the deal in such a way that it doesn’t need congressional confirmation.

But there is a flip side. You could expect any of the Republican candidates running to replace Obama to be unenthusiastic, if not outright hostile, about sticking to a global agreement to limit emissions – binding targets or not. So international peer pressure might be the only way forward. (Wouldn’t it be interesting if it were the Chinese pressing the Americans to be a good citizen on a major global issue, rather than the other way around?)

While that’s hypothetical, what’s not hypothetical is that actions by governments set the framework in which businesses, civic institutions and individuals act. That’s true of business regulations, tax policy and interest rates. It’s also true of the Paris climate agreement. Despite its shortcomings, the accord establishes climate change as a global priority that needs to be taken into account in investment decisions, corporate strategy and research priorities. Even if the U.S., for domestic purposes, decided to ignore the agreement, businesses still would have to deal with it in the international realm. 

With government encouragement, the focus should increasingly shift to business investment and new technology. That could make a huge difference.

At the start of the Paris talks, Bill Gates and a group of billionaires committed themselves to working with governments to develop new technologies and bring them to market.

That also was the focus of the reaction from Al Gore, who already has been sounding like something of an optimist on climate change. 

The agreement, Gore said, “sends a clear signal to governments, businesses, and investors everywhere: the transformation of our global economy from one fueled by dirty energy to one fueled by sustainable economic growth is now firmly and inevitably underway.”