Disasters happen when facts on the ground contradict our stubborn vision of how the world ought to work.

Yet, after we absorb the human pain and suffering they cause, calamities have their useful side. “Wake-up calls,” the glib would say.

The jaded would be more likely to side with George Orwell and describe disasters, including the one still unfolding in Houston, as part of the never-ending struggle “to see what is in front of one’s nose.”

Metro Atlanta had such a learning experience only a few months ago, when the fiery collapse of a bridge on I-85 demonstrated the fragility of a one-dimensional, gasoline-based transportation system. Some Republican minds were already changing, but at $12 million with no loss of life, the reinforcing lesson was a cheap one.

A month after the I-85 bridge was rebuilt, Speaker David Ralston told a special House transportation commission that he was open to regular state funding of mass transit in metro Atlanta and elsewhere.

Seeing the world as it is will be far more expensive on the coasts of Texas and Louisiana.

The death toll had reached 39 as I write this, and more bodies are sure to be found as the water retreats through the weekend. One in every 10 structures in Harris County, which includes Houston, is flooded. Some 44,000 homes have been destroyed or heavily damaged.

Some of Hurricane Harvey’s lessons are already forcing at least situational shifts in thinking. Just as there are no atheists in foxholes, “there are no conservatives in waist-deep water,” observed Rex Nutting in The Wall Street Journal.

In 2013, U.S. Sens. Ted Cruz, John Cornyn and all but one Republican member of Congress from Texas voted against a $50 billion aid package for victims of Hurricane Sandy up and down the East Coast. The Texans declared it to be larded with pork. (It wasn't.)

FEMA officials tell us that more than $57 million in individual assistance has already been paid out in the Houston area. A Hurricane Harvey aid package will be introduced when Congress reconvenes this week. We don’t know the dollar figure, and we don’t know what it will buy.

But we do know that Ted Cruz & Co. will refer to it as a lean slab of Angus beef and vote to approve it.

Likewise, Houston has drowned the voices, at least temporarily, of those who say a social net should be knitted solely by the local community, not the government.

As morale-boosting as it was to see the “Texas navy” at work, the small, private armada of jon boats had the heart, but not the muscle, to rescue Houston. As helicopter after helicopter showed.

Likewise, this Sunday will surely see pews filled with weary churchgoers exhausted from a hard week of volunteer work. But they were not enough. So perhaps we owe some thanks to prosperity evangelist Joel Osteen, whose Lakewood Church had to be shamed into opening its doors to flood evacuees. Osteen showed us that charity has finite limits.

There is a reason that Gov. Greg Abbott summoned 13,000 members of the Texas National Guard to the Houston area. Sometimes the government is the community.

The realities of Harvey could also force Texas to call a truce in its war against illegal immigration. According to a Pew Research Center report published earlier this year, Houston had 575,000 unauthorized immigrants — the third-largest population concentration in the nation.

Illegal immigrants make up between one-quarter and one-half of the construction workforce in the Houston area. “Who helped rebuild New Orleans? That was immigrant labor. What are they going to do in Houston when they want to pick up and deport everybody from that state?” asked Charles Kuck, an immigration attorney in Atlanta.

Then there is the topic of climate change.

This week, if you were a Houston flood evacuee stewing in a shelter, and in possession of a working smartphone, you might have taken the time to read an investigative report that The Texas Tribune and ProPublica published last year. It described Houston's vulnerability to a great flood in terrific detail, including the threats posed by compromised chemical and petroleum operations.

You could learn how one of Houston’s two top flood program officials dismissed warnings about disappearing marshland and overbuilding in flood plains. Scientists were “anti-development.“ And the claim that “these magic sponges out in the prairie would have absorbed all that water is absurd,” he said.

The investigation was based on a scenario in which Houston was hit by a saltwater surge made more severe by rising sea levels. Which was not the case in Houston last week. Harvey killed with fresh water, by dropping massive amounts of rain on a single area — another phenomenon with links to climate change.

“Unlike so many GOP leaders, many of the oil and gas firms operating in Houston at the very least publicly acknowledge the legitimacy of today’s climate science,” The Houston Chronicle reported as Harvey rolled in.

That kind of blind spot isn’t necessarily limited to Houston, or Republicans.

Back in April, Mathew Hauer, an applied demographer with the University of Georgia, published a paper on what high-ground U.S. cities are most likely to become destinations for coastal residents forced from their homes by rising sea levels.

Atlanta was No. 3 on his list, behind Austin, Texas (which is close by Houston), and Orlando, Fla.

Hauer said his paper has prompted interest from the National Oceanic and Atmospheric Administration and the Environmental Protection Agency, but — so far — not from federal or state emergency management officials.

His study is a fact in front of one’s nose. The question is whether we will choose to see it.