It’s time to discuss institutional racism again. Yeah, I know many of you think it’s bullshit.   That doesn’t make your thinking right.  So, humor me- and read what I am going to discuss today with an open mind.  (Breathe in, breathe out… breathe in, breathe out.)

Let’s go back to the 1930’s.  When a well-thinking government decided to fund the Home Owner’s Loan Corporation (HOLC).  Yes, this was part of FDR’s New Deal.  But, it was really a new deal for white folks; not so much for Black folks.

What did the HOLC do?  It helped folks keep their homes by offering low-interest mortgage loans.  Not all folks- folks in white neighborhoods- yes.  Folks in minority neighborhoods- hell, no.

The HOLC allocated regions of 240 US cities into zones.  A were the best investments. D were the hazardous ones. Of course, these zones were color-coded.  And, D was outlined in Red.  Oh- that’s where the term ‘redlining’ came from, is it?  (You can bet that working class Black and immigrant neighborhoods comprised the redlined zones.)

This codification existed up until 1968, when we finally passed the Fair Housing Act- which officially terminated redlining.  (You can bet the banks found other ways to continue discrimination, but I will limit my discussion today to these historic biases that exist to this day.)

To this day, redlined districts all manifest disinvestments, lower property values, lower home ownership rates, and reduced credit access. (So much for the Fair Housing Act’s positive effects.)

Oh, wait there’s more.  Like more pollution, like folks at greater health risks (cardiovascular disease, diabetes, etc.)  And, as I’ve intimated before (in a more technological sense), these neighborhoods all form urban heat zones.

As I outlined last July (Super Cool), there are ways we can now address these urban hot zones.  Not that anyone has really acted upon my suggestions.  But, maybe as you read the rest of this post, you will request your Senators and Congresspersons to redress this federally-created discrimination.

I should say that this research is not mine. Drs.  Jeremy Hoffman (Science Museum of Richmond), Vivek Shandas (VCU, also in Richmond), and Nicholas Pendleton (Portland State University) detailed these effects in the article “The Effects of Historical Housing Policies on Resident Exposure to Intra-Urban Heat:  A Study of 108 US Urban Areas” (published in Climate).

The research demonstrated that within each city, it was simple to discern the surface temperature anomalies. (How the summertime surface temperature of each HOLC tier compared to the overall surface temperature of the city.)  The data also included the average percentage of impervious land surface cover (heat-absorbing materials like asphalt) and tree cover for each tier.

The heat island effect is related to all the urban building materials (bricks, asphalt) that absorb solar energy during the day only to release the heat back out in the afternoon and evening.   We feel these effects ourselves all the time- walking across a parking lot on a hot day.  We immediately recognize the sweltering heat radiating up from the asphalt, the rush of warm air as a car passes us by.   It doesn’t help that there are tall buildings nearby that obstruct wind flow to cool down or attenuate the effects.  This is exactly why cities can be 4 C hotter than less built-up areas nearby.

Sure, trees and parkland mitigate these effects- but those mitigants are typically found in the wealthier neighborhoods- you know, the white neighborhoods. With climate change, these differences will only become even more pronounced.

Given these facts, we should not be surprised that 94% of those 108 cities studied had stepwise gradients in summertime temperature anomalies- from A to B to C to D. The D rated (redlined) neighborhoods were 2.6 C hotter than the A regions, but that difference approached 7 C in some cities.  These were associated with less tree cover, more asphalt cover.

It’s absolutely clear- some 80 years down the road- that these historic discrimination zones continue to exist today.  A zones are still shady and leafy, D zones are built-up and smelly, replete with freeways, factories, and strip malls.

It’s long past time to reverse this discrimination.