Is it time for action on climate change?

Wildfires are raging across a drought-stricken West. Cities up and down the East Coast are living with poor air quality. Vast swaths of Belgium, Germany, the Netherlands and Switzerland are covered in muck from massive floods.

Torrential rain has stricken central China, inundating subway tunnels in Henan province. The toll in death and misery continues to rise.

Yes, it is too early to say for sure that climate change is behind each of these latest instances of alarming weather, but that does not mean humanity can ignore the distinct possibility that they are related. Certainly, these calamities foreshadow life as climate-change-induced disasters become more frequent.

Human society is unprepared.

The Pacific Northwest, one of the most developed areas on the planet, melted in last month’s high temperatures because the region is unaccustomed to hot conditions. Germany’s Rhineland, another of the world’s richest regions, did not have the infrastructure to cope with supposedly once-in-a-millennium floods.

People might think of global warming as just hotter days, but it is far more: It means that massive wildfires induce asthma attacks in cities a continent away, an experience that metropolises such as New York and Washington understand viscerally after this week.

Meanwhile, in the Chinese city of Zhengzhou, a year’s worth of rain has fallen in less than a week, surpassing historical records.

Some 200,000 people have been evacuated from their homes, and some 500 people had to be rescued from swamped subway tunnels. Survivors described standing on seats to keep their heads above water.

To be clear: Heat waves, droughts, wildfires, torrential rains and floods all occurred before humans began warming the planet.

Scientists cannot say how much climate change factored into a particular natural disaster until they conduct an attribution study that calculates the extent to which global warming contributed. But now, all the same natural forces that previously conspired to produce such events are doing so within a system that human beings have primed with more energy.

A common analogy is to a basketball court: Some good players could always dunk, given the right circumstances, but dunking would occur more often if the floor were raised.

The ongoing misery in the United States, Germany and China reflects exactly the sorts of calamities that boosting global temperatures promises to make more common, more extreme and more deadly. Unsurprisingly, attribution studies have shown again and again that lots of recent unusual weather had a climate change component.

There are two lessons.

First, we must reduce the greenhouse gas emissions that are driving global warming. Second, even as we do so, we must prepare for the temperature rise that is unavoidable, the result of the gases industrial nations have already pumped into the atmosphere. That means hardening infrastructure to withstand not just the climate under which human society developed, but also the one with which human beings will have to cope.