Sometimes the people who call the loudest for change and innovation are the least able to recognize it when it comes along. The Paris Agreement is a case in point. Over the last week, critics on both the left and right have lined up to condemn it as a fraud and a failure, when it is neither.Something new and important is unfolding around climate change and the critics are missing it. The pendulum of public opinion has been swinging; it is moving away from skepticism about the threat and toward belief and commitment. More and more people are coming around to the view that climate change is real and serious; and that governments need to take action to address it.Unfortunately, critics of the Agreement are so focused on the policy tools to fight climate change that they ignore the role of the political culture around it. They point to the Agreement's lack of enforcement mechanisms and the failure to set more rigorous targets for greenhouse gasses. These, they argue, are grounds to declare it a failure.I might agree if I thought Paris was our last best chance to get a full-fledged plan, but I do not. There will be further talks and there is reason to be hopeful about the outcome. To get the right result, however, what we really need now is public buy-in. A shift in public values could change everything. This is not wishful thinking. We've seen it happen before.When Prime Minister Paul Martin announced his intention to legalize same-sex marriage in 2005, the government braced for serious opposition. Yet when the new law passed, debate and resistance were minimal. People simply adjusted. Today, much of the population not only accepts same-sex marriage, but has rallied around it.This bit of social change might seem like an anomaly that came out of nowhere, but it isn't. There was a long incubation period during which Canadians were exposed to all kinds of discussions on gay rights. At the time, there were no obvious signs that all these ideas were percolating below the surface—people's views seemed pretty consistent—but then, suddenly, people were ready for change. All they needed was the opportunity and Martin provided it.Something similar appears to be happening with climate change. A long series of public discussions at both national and international levels has been inching its way through our public consciousness. While critics on the left warned of disaster, those on the right insisted the crisis was invented or exaggerated.For the most part, the public responded cautiously, making progress difficult and slow, especially at the international level. Unsurprisingly, governments followed suit. They are unlikely to push ahead with costly and disruptive measures when public support is lacking.That may be changing. The Paris Agreement raises the profile of climate change to a new level and, for the first time, successfully rallies the nations of the world around the idea that they must work together to neutralize the threat.This, in turn, could create a new dynamic in future global discussions, helping to draw the participants closer together, commit them more deeply to the process, and prepare them to make the concessions and compromises necessary for real progress.At the same time, the growing profile around climate change would draw even more people into the discussion, helping to build legitimacy and support for the talks. If so, a real agreement may not be far off.That being said, questions around urgency remain a stumbling block. According to James Hansen, the “father of climate change awareness,” the real problem with the Paris Agreement is that it is too little, too late. In his view, if we don't respond immediately with major GHG reductions, large parts of the planet will be uninhabitable within a couple of generations.Frankly, I don't know if this is true, but I do know the questions around urgency have not been settled. While people like Hansen insist we are already at the tipping point, others disagree and balk at the call for extraordinary measures. A huge new carbon tax is still a step too far for most citizens and their governments. Hence the lack of hard measures in the Paris Agreement.Whatever one makes of this debate, trashing the Agreement is hardly the answer. It is a big driver of the kind of social change needed to get a real plan. The Agreement has already helped focus climate change as a global issue. As a result, sustainable development is emerging as a core value of peoples everywhere and a central theme in the global public policy agenda. The Agreement is an important tool to raise awareness and keep the momentum going. These are not insignificant tasks.Finally, if Hansen is even partially right about the urgency of the situation, science will soon make this incontestably clear. With public opinion now coming onside and an international framework taking shape, governments will be far better positioned to respond.So, yes, the Agreement is far from perfect, but that does not make it a fraud or a failure. The Paris summit is not the final word on climate change and we shouldn't treat it as such. There is still a long way to go. Let's not throw in the towel yet.Dr. Don Lenihan is Senior Associate, Policy and Engagement, at Canada 2020, Canada's leading, independent progressive think-tank. Don is an internationally recognized expert on democracy and Open Government. He is currently the Government of Ontario's principal advisor on its Open Dialogue Initiative. The views expressed here are those of the columnist alone. Don can be reached at:[email protected] or follow him on Twitter at: @DonLenihan