Two stories flagged by our Gristmill bloggers yesterday got me thinking. There’s this one, about San Francisco’s “managed retreat” from rising sea levels, and this one, about New York Gov. Andrew Cuomo (D) planning to allow some coastal communities to “return to nature.”

Both mean the same thing: Shit is getting real. Coastal cities are facing decisions about how to plan for higher seas and more frequent floods, about which lands to abandon and which to “up armor” with levies and seawalls. These are present-day decisions, not something for the distant future. Whether or not the particular plans in SF and NYC go through — they are expensive, and will face much local resistance — they are only the beginning. And it’s not just the coasts. Decisions of a similar spirit will face places like Las Vegas and Phoenix, which exist only by virtue of a steady supply of outside water. What will happen in 10, 20, 30 years, when there are more droughts and less rain? What can be sustained and what must be abandoned?

As I’ve said before, long-term adaptive planning is going to be a ubiquitous necessity in the coming century. There will be many more “managed retreats” — at least, if we’re lucky they’ll be managed.

So, when these decisions are made, who benefits? Who gets protected when the weather comes? Who gets made whole after the weather has done its damage? If a community needs to be abandoned to nature, how is it compensated and where are its people put?

Among other things, these decisions are going to involve some incredibly delicate class and racial politics. Poor and minority communities are generally hardest hit by environmental stresses and least able to adapt to them. They also tend to be poorly represented in state and federal politics. To put it bluntly, poor and minority communities tend to get screwed in politics, and there’s good reason to fear they’ll be screwed when urban adaptation decisions are made.

We saw this play out when Hurricane Katrina hit New Orleans, which was already unusually segregated and had already sorted poorer people into more vulnerable lowlands. The laggardly public response to Hurricane Katrina has been seen by blacks as inexorably bound up with race — though, interestingly, very few white people saw it that way. The recovery has been almost as uneven as the initial response. As of 2010, 100,000 residents still hadn’t returned, 80 percent of whom were black. Rebuilding efforts differ sharply depending on whether they are privately funded (by people with the resources to do so) or publicly funded. Today the cities’ neighborhoods are even more segregated than they were before the hurricane, with blacks even more concentrated in vulnerable areas.

In the wake of Katrina there was talk of abandoning some areas rather than continuing to subsidize them through public insurance. But in the stew of class and racial suspicion during and after the hurricane, such discussions had very little chance of unfolding rationally. Blacks quite reasonably suspected that such talk was code for screwing them even more, driving their communities from the city entirely.

Anyway, I don’t want to get into a whole thing about reconstruction in New Orleans. The point is just that the city, with its exaggerated class and racial divides, offers a kind of heightened case study for the sorts of class and racial stresses that are going to face urban areas preparing for climate chaos.

I wish I could offer some sort of Grand Idea about how these stresses can be anticipated and mitigated, probably something that uses the words “stakeholders,” “collaborative,” and “open” a lot. But honestly, I have no idea. The cynic in me thinks that poor and minority people getting screwed is a kind of axiom, a feature of public life as predictable as the rising sun. Climate will increasingly force big, rushed, fear-based decisions on us, and those are precisely the circumstances in which poor and minority folk are most likely to get screwed.

But y’all shouldn’t be cynics like me. You should work proactively to make sure that adaptation efforts are not only effective but equitable, that they respond rationally to the changing climate but also compassionately to the needs of those most likely to suffer from it. The alternative is an America that drifts even further from its founding ideals.