Deep Dive: The Wet Bulb Problem

Wed., June 30: Why the PNW heatwave should scare the hell out of you + improving North Carolina democracy + landlords win and lose + budget cuts for urban DAs + Chapel Hill development wars


1. Deep Dive: The Wet Bulb, the Infrastructure Bill, and an Inhospitable Planet

On Monday, Salem, Ore., reached a record-shattering 117 degrees. In Portland, it was 115—the highest temperature ever recorded at the airport and more than 40 degrees above normal. Seattle hit 108, also a record. The heat dome over the Pacific Northwest baked a region unaccustomed to and ill-equipped for anything like this kind of weather. (I grew up in South Florida, where we air-condition everything, and those numbers terrify me.) Even the higher elevations didn’t escape the blast furnace, which meteorologists blamed on a stalled high-pressure ridge.

The real culprit, of course, is climate change.

The New York Times:

Last month the National Oceanic and Atmospheric Administration adjusted its “climate normals,” baseline data of temperature, rain, snow, and other weather variables collected over three decades at thousands of locations across the country.

“We’re really seeing the fingerprints of climate change in the new normals,” MichaelPalecki, who manages the project at NOAA’s National Centers for Environmental Information, said when the normals were updated.

Last year tied 2016 as the hottest year on record, as global temperatures continued their relentless rise brought on by the emission of heat-trapping greenhouse gases.


Karin Bumbaco, Washington’s assistant state climatologist, said that any definitive climate-change link could be demonstrated only by a type of analysis called an attribution study. “But it’s a safe assumption, in my view, to blame increasing greenhouse gases for at least some portion of this event,” she said.

On a global average, the world has warmed about 1.8 degrees Fahrenheit since 1900. “When you have that warmer baseline, when you do get these extreme events it's just going to get that much warmer,” she said.

Here’s what that increase looks like:

This heatwave is already dissipating, especially along the coast. The point, however, is that these freak events are less freakish than they were two decades ago. Two decades from now, they’ll be almost commonplace. America is getting hotter. The Southwest is getting drier. The eastern and central parts of the country are getting wetter.

What you’re looking at is, well, bad. It’s not just that California farms won’t get enough rain to survive while lowland Louisiana will flood. It’s that the additional heat and humidity you’re seeing in the eastern half of the country is showing up all over the globe, reaching a point beyond what the human body can tolerate.

This is already happening. It’s going to happen a lot more, and in a lot more places, in the very near future.

As Scientific American reported last year:

High temperatures prompt the human body to produce sweat, which cools the skin as it evaporates. But when sky-high humidity is also involved, evaporation slows down and eventually stops. That point comes when the so-called the wet-bulb temperature—a measure that combines air temperature and humidity—reaches 35 degrees Celsius (95 degrees Fahrenheit).

Previous analyses using climate models suggested that parts of the Persian Gulf region, the Indian subcontinent and eastern China would regularly see heat waves breaching this limit by later in the century. … [Colin] Raymond and his co-authors … found that extreme humid heat occurs twice as often now as it did four decades ago and that the severity of this heat is increasing. Many places have hit wet-bulb temperatures of 31 degrees C and higher. And several have recorded readings above the crucial 35-degree-C mark. …

These humid heat extremes have already emerged in the same places that earlier modeling studies had identified as future hotspots. Most are coastal areas that are both near warm bodies of water, which can supply abundant moisture, and subject to soaring overland temperatures. Others, particularly in the Indian subcontinent, are regions where monsoon winds usher in moisture-laden air.

The SA story was based on a study in Science Advances that was backed by NOAA.

NOAA reported:

The southeastern United States, especially along the Gulf of Mexico, had multiple incidences of wet-bulb temperatures at or above 88°F; specifically, in east Texas, Louisiana, Mississippi, Alabama, the Florida Panhandle, Arkansas, and North Carolina. …

“Wet-bulb temperatures above 86°F (30°C) are rare in the U.S. As wet bulb temperatures approach 95°F, even the healthiest people, relaxing in the shade without heavy clothing and with an endless supply of water, cannot prevent themselves from overheating,” [study co-author Radley] Horton said. “Even at lower wet-bulb temperatures, like 79°F (26°C), those with pre-existing health conditions (like respiratory, cardiovascular, and renal disease), the elderly, as well as those performing strenuous outdoor labor and athletic activities, are at a high risk.”

The authors note, for example, that the 2003 European heat wave caused over 50,000 deaths at wet-bulb temperatures close to 79°F. In the United States where air conditioning is more widespread, the 1995 Chicago heat wave reached wet-bulb temperatures of 85°F and killed over 700 people.   

Matthew Lewis, the communications director at the group California YIMBY, tweeted a long thread about the wet-bulb problem.

Some important highlights:

  • “We’re already seeing multiple wet-bulb temperatures per year in multiple locations. By mid-century, parts of the Southeastern U.S will see *weeks* of wet bulbs *every year.* This is quite bad. Thousands of people will die on each of those days.”

  • “This has ... implications. Human habitations get very difficult to manage when thousands and thousands of people are dying every day, for weeks, every year.”

To get a sense of how wet-bulb temperatures work, here’s a calculator.

  • For example: Today’s high is expected to be 92, with a relative humidity of 65%.

  • The wet-bulb temp: 82.14°F.

  • The Pacific Northwest’s saving grace is having a dry heat—which is, in fact, a real thing. When Portland hit 115°, its humidity was only 13%, so its wet-bulb temp was just 75°. All things being equal, it’s more dangerous here than there—except that all of our buildings have air conditioning, but cities in the PNW weren’t built with insane heatwaves in mind.

  • If the humidity rose to 85% or the air temperature hit 97°, the wet-bulb temp would exceed 86°.

  • Getting to a wet-bulb of 95°—the point at which even a healthy body can no longer function—isn’t that unthinkable: 103° and 75% humidity would do it.

Tl;dr: The near-future is people—quite likely poor people of color—dying en masse from heat. To say this will destabilize our culture doesn’t even begin to describe it.

Aggressive actions to curb carbon emissions can mitigate some—not all—of what’s on the horizon.

  • On Monday, dozens of climate activists were arrested in a White House protest of the bipartisan infrastructure deal, which has shed many of the climate-related provisions in President Biden’s original infrastructure proposal.

  • “The blockade at the White House and resulting arrests followed a march and rally of more than 500 activists and congressional Green New Deal champions—Reps. Alexandria Ocasio-Cortez (D-N.Y.), Jamaal Bowman (D-N.Y.), and Cori Bush (D-Mo.). It also comes after Biden and lawmakers announced a $579 billion bipartisan compromise on infrastructure last week.”

  • “In response to Monday's protest, White House Press Secretary Jen Psaki pushed back against progressive critiques of the deal, saying, ‘I would dispute the notion that it doesn’t do anything for climate, which some are arguing.’”

Anything is doing a lot of work there. There’s some money for public transit, rail, electric buses, and electric vehicle charging stations—woo—as well as $47 billion for climate resiliency, which is going to be very important very soon.

But it’s not what was pitched or what Biden campaigned on.

The NYT:

The president had hoped to use a sweeping infrastructure bill as a vehicle to enact a national “clean electricity standard” requiring power companies to gradually ratchet up the amount of electricity they generate from wind, solar and other sources until they’re no longer emitting carbon dioxide. That is not included in the bipartisan bill, nor are the hundreds of billions of dollars in spending on tax incentives for wind, solar, and other clean energy.

The line is that these things will get folded into the magic reconciliation bill that Democrats will pass on a party-line vote alongside the bipartisan infrastructure bill, which Republicans will support despite knowing Democrats are jamming through the other one anyway. And all of that hinges on keeping Joe Manchin on board—not just because he’s the most conservative Dem in the Senate, but because he comes from a coal state.

Some Democratic strategists are skeptical about the budget reconciliation route. Senator Joe Manchin III of West Virginia and Senator Kyrsten Sinema of Arizona, both Democrats, have balked at voting for a reconciliation bill that has no Republican support. Mr. Manchin, who represents a coal-rich state, is unlikely to support a plan designed to end demand for coal.

Democrats have to pass a budget, and they’ll end up doing it through reconciliation, with Manchin and Sinema on board.

  • Because enough Senate Dems have said they absolutely won’t support anything that doesn’t include climate provisions, something will be in there.

  • But thanks to Manchin and Sinema, it won’t be as much as we need to avert the disaster that is not only coming but already here.

In the meantime, cities and states need to plan seriously for major heat events, and that’s where climate resiliency comes in:

  • Plant trees—lots and lots and lots of them—to provide shade

  • Tall buildings in compact city centers also provide shade

  • Incorporate cool or green rooftops

  • Use cool pavements, meaning pavement that reflects solar energy

  • Establish community cooling centers

  • Modify infrastructure to withstand severe heat

  • Bolster the power grid. Severe heat will put a lot of pressure on Duke Energy. If there are widespread outages, people will die.

It’s too late to avert the crisis. The best we can do is mitigate it while we slow the planet’s heating. The longer we wait to start, the more impossible the task becomes.

2. Building a Better NC Democracy

Yesterday, the Institute for Southern Studies and N.C. Voters for Clean Elections, along with eight other good-government groups, released a 64-page report titled Blueprint for a Stronger Democracy, outlining ways for the state to improve its elections process.

Among the recommendations:

  • Implement automatic voter registration and allow same-day registration on Election Day as well as during early voting.

  • Don’t purge inactive voters, and be careful about purging voter rolls generally.

  • Restore voting rights to felons upon release from incarceration.

  • Provide adequate resources for local elections administration.

  • End gerrymandering and join the National Popular Vote Interstate Compact.

  • Strengthen laws restricting coordinated campaign committees that sidestep finance limits.

  • Return to nonpartisan judicial elections.

Most of these are smart, forward-thinking, even obvious—and sure to be ignored by the General Assembly.

3. Council of State Rejects Eviction Moratorium

Governor Cooper asked the Council of State yesterday to back a one-month extension of the eviction moratorium, which has been in place statewide since October.

Following the CDC’s decision to extend its national evictions moratorium [through July 31], Governor Cooper on Monday asked for the necessary concurrence from the Council of State to extend the evictions moratorium order.

Council of State members have until 5pm on Tuesday, June 29 to consider extending the state evictions moratorium or revoke the protections extended to residential tenants.

I had questions:

  • Why did Cooper feel the need to ask for a “necessary” concurrence now, when he hasn’t before?

  • If the CDC has a moratorium in place, what’s the point of a state moratorium?

  • What happens if a majority of the Council says no?

The Council said no, and according to a late-afternoon press release, Cooper will oblige:

The state evictions moratorium will end July 1 after Republican members of the Council of State rejected a one-month extension, which would have aligned with the national CDC evictions moratorium through July 31. …

Some North Carolina renters retain protection against evictions based upon the CDC moratorium. Renters who:

  • Received a federal stimulus check in 2020 or 2021, or 

  • Were not required to report income to the IRS in 2020, or 

  • Earn less than $99,000 ($198,000 filing jointly) per year, and 

  • Cannot make rent payments due to lost income, 

may provide a signed declaration to their landlord that protects them from eviction while the federal moratorium remains in effect. The declaration form may be found here.

The fate of the CDC moratorium had itself been an open question after a federal judge had ruled it unconstitutional. But in a 5-4 ruling, the Supreme Court settled that issue yesterday, with Chief Justice Roberts and Justice Kavanaugh siding with the liberals to keep it in place.

The decision is a blow for the National Association of Realtors, the powerful lobbying group that funded the challenge to the pandemic-related moratorium on behalf of two of its chapters.

The association had asked the court to act on an emergency basis to vacate a stay on a lower-court decision overturning the ban, saying the “stay will prolong the severe financial burdens borne by landlords under the moratorium for the past nine months.”

The Centers for Disease Control and Prevention's moratorium is currently set to expire July 31 after the Biden administration extended it last week, with the CDC saying it intended the move as the final extension. Some six million renter households are behind on rent, according to a recent Census survey.

Kavanaugh wrote in Tuesday’s decision that he agreed with the lower-court ruling that the CDC had exceeded its authority but that its pending expiration swayed his thinking. (Politico)

4. NC Senate Budget Cuts Prosecutors, Public Defenders in Urban Counties

I mentioned yesterday that earmarks in the N.C. Senate’s budget proposal disproportionately favored rural Republican counties. It seems funding for prosecutors and public defenders went the same route.

Republican senators say these aren’t partisan moves.

Per the Charlotte Observer:

State Sen. Danny Britt, a Republican who represents rural Columbus and Robeson counties, said the Senate’s choice involved the haves vs. the have-nots.

Mecklenburg County, he said, had the money to hire additional prosecutors beyond the 58 that the state provides. That’s a luxury many rural counties can’t afford, he said.

“I think the larger context here is that Mecklenburg County is one of the wealthiest in the entire state,” Britt said in a statement to the Observer on Monday.

The rationale for the PD moves is roughly the same.

  • While slashing income taxes, Republicans expect local governments to make up the difference by raising taxes on their residents.

5. In Chapel Hill, Every Development Is Controversial

Most places, a mixed-use apartment/townhouse development that includes a decent chunk of affordable-ish housing (80% and 65% of AMI), three acres of green space, a park, a nature area, and a fenced-in playground, all along a bus rapid transit line, wouldn’t generate a deluge of hate mail.

But most places are not Chapel Hill. On Monday, the Town Council approved the Aura Chapel Hill development on a 5–3 vote, concluding a 10-year (!) fight over the property.

Some council members have received “threatening and hateful emails” ahead of the vote, Mayor Pam Hemminger said.

Hemminger was joined by council members Hongbin Gu and Allen Buansi in voting against the development. …

“It’s also been frustrating to see the misinformation provided about both the process and the project in an effort to alarm the public and garner support for a particular position,” she said. “These types of behaviors don’t help us, and they don’t get to better decisions.” (N&O)

The development will have 361 apartments and 58 townhouses. It will also contain 650 parking spaces and add some 1,500 cars to local traffic.

RELATED: Council member Allen Buansi has announced that he won’t seek reelection. Of the other incumbents whose terms are up, Karen Stegman has already filed, as has challenger—and amazing restauranteur—Vimala Rajendran.


  • In a press release, GoTriangle announced that it—along with GoRaleigh, GoDurham, and GoCary—will continue to suspend bus fares for another year, through June 30, 2022. Chapel Hill Transit remains free, as it always is.

The transit agencies suspended fares in March 2020 due to the COVID-19 pandemic as they asked riders to use the rear door to board buses to help maintain social distancing. They also sought to ease financial burdens for the frontline workers and community members who were relying on transit to get to critical jobs or food and health care.