This may be remembered as the COP of hard realities—the moment when the world was confronted like never before with both the harsh evidence of an impending climate emergency and the stubborn political realities standing in the way of an emergency response.

One of the core challenges on display here at COP 24 in Katowice, Poland, is the tendency of some to fixate on some realities while ignoring—or denying—others.

That was nowhere more evident than in the absurd spat Saturday over whether countries should “welcome” or merely “take note of” the latest scientific findings of the Intergovernmental Panel on Climate Change: essentially, that we have just a decade to take the steps needed to avert calamitous climate change.

A handful of countries, including the United States and Saudi Arabia, blocked agreement by insisting on the weaker language—but the issue is certain to surface again before this COP is done.

Whatever words parties settle on, they are only of fleeting symbolic significance. The IPCC’s report stands on its own. Its science is irrefutable. Its warnings ring true not only to virtually everyone here, but to countless others around the world—not least because so many are already experiencing our cruel new climate realities firsthand.

The other realities presenting themselves in Katowice are of a more political nature. They speak to why—even where citizens and governments fully appreciate the evidence laid out by the IPCC—it is so difficult to mount an effective response.

Science and economics clearly demonstrate that over the long term, the benefits of strong climate action far outweigh the costs (see, for instance, the report released here by the World Health Organization on the health impacts of climate change). The problem is that the near-term costs of climate action are unevenly distributed—and unless carefully managed, fall disproportionately on those least able to afford them.

The most immediate illustration came just ahead of the COP, when the “yellow vests” took to the streets of France to protest a fuel tax increase intended to curb carbon emissions. President Emmanuel Macron, who has tried to position himself as a climate champion, was forced to rescind the modest tax hike.

German Chancellor Angela Merkel—over the years, one of the world’s staunchest climate leaders—faces a similar challenge. A commission charged with developing a strategy to manage Germany’s coal “exit,” which was to wrap up its work by the end of 2018, has now extended its deadline in the face of strong resistance from both industry and labor.

Meanwhile, Poland, the host of COP 24, has not been shy about highlighting the continuing importance of coal to its economy, to the point of featuring jewelry and soap fashioned from coal at its country pavilion.

To highlight the economic challenges facing many countries, Poland is urging governments to join a declaration that a “just transition of the workforce and the creation of decent work and quality jobs are crucial to ensure an effective and inclusive transition to low greenhouse gas emission and climate resilient development.”

Then there is, of course, the United States.

Apart from distancing itself from the IPCC report, the United States has focused its high-level messaging on the role of fossil fuels and nuclear power in addressing energy and climate needs. Broadly speaking, that’s actually a message to which C2ES subscribes (assuming the fossil fuels are accompanied by carbon capture). But the U.S. projects it in a way that tends to encourage more confrontation than conversation.

In a U.S. side event that, predictably, drew rowdy protests, Wells Griffith of the White House, put it this way: “Alarmism should not silence realism.”

There, in five words, is the problem: trumpeting some realities while trashing others. Yes, nuclear and carbon capture are part of the answer. But “realism” also includes recognizing that our climate situation is, indeed, alarming.

In the end, certain realities are an immutable matter of physics: Human activity is overheating the planet. Other realities are a matter of political will: with enough will, we can transform them.

As President Macron discovered, it will be difficult to build—let alone sustain—public support for effective climate action without dealing with the inequitable distribution of costs. We can’t expect the most vulnerable to bear the brunt of a transition that benefits us all.

From a policy perspective, we know how to do that: Several of the carbon pricing bills introduced in Congress, for instance, would provide assistance to low-income households and to workers and communities disadvantaged in the low-carbon transition.

But first—and urgently— we have to get past denial on all sides and face the full set of realities before us.