Science

We Mapped Heat in 3 U.S. Cities. Some Sidewalks Were Over 130 Degrees.

Published

2 years ago

July 17, 2024

We Mapped Heat in 3 U.S. Cities. Some Sidewalks Were Over 130 Degrees.

We usually talk about summertime heat in terms of how hot the air is, but there’s another metric that matters: the temperatures of roads, sidewalks, buildings, parking lots and other outdoor surfaces. Hot surfaces can make the places people live and work more dangerous, and can increase the risk of contact burns.

Just consider this image, captured recently by satellite, of surface temperatures across Phoenix.

Sources: U.S.G.S. Landsat via Google Earth Engine; U.S. Census.

Note: Satellite image taken at 12:03 p.m. local time. Higher-uncertainty pixels removed.

Around noon on July 10, huge parts of the nation’s fastest-growing large city were 120 degrees Fahrenheit, about 49 Celsius, or hotter to the touch. Had you been unlucky or unwise enough to actually touch it with bare skin, it could have caused injury within minutes.

On the city’s desert fringes, in territory governed by Native American nations, the land was even hotter, 150 degrees or more.

So far this summer, the Arizona Burn Center, which serves Phoenix and the broader Southwest, has admitted 65 people for severe heat-related burns, according to Dr. Kevin Foster, the center’s director. Six of these people died from their injuries. Last summer, the center recorded 14 such deaths.

Yet even that figure is small compared with the 645 heat-related deaths that were identified last year in Maricopa County, which includes Phoenix. That was the highest number on record for the county. (This year, the county has so far reported 23 heat-related deaths and is investigating 322 more.)

Surface temperatures are just one of many factors that cities are thinking about as they try to protect residents from extreme heat, said Ladd Keith, an associate professor in the School of Landscape Architecture and Planning at the University of Arizona.

In an environment as complex as a city, heat can harm people, pets and wildlife in many different settings and circumstances, Dr. Keith said. For officials, it can be tricky to figure out which exact combination of policies and actions might prove most beneficial to public health.

Phoenix, for instance, is trying to plant more trees and increase shade. The city’s “Cool Pavement” program has treated 120 miles of asphalt to help it reflect more sunlight and stay cooler as a result. But from a cost-benefit perspective, might it make more sense to put those resources toward building more heat-tolerant homes or addressing homelessness instead? “It’s really hard to know what that mix is,” Dr. Keith said.

What’s clear, he said, is the need to figure it out quickly. “Heat deaths are climbing faster than any of our investments to prevent them,” he said. And human-caused global warming keeps increasing the frequency and intensity of dangerous heat waves. “We’re chasing a moving target very slowly,” he said.

Sources: U.S.G.S. Landsat via Google Earth Engine; U.S. Census.

Note: Satellite image taken at 11:45 a.m. local time. Higher-uncertainty pixels removed.

Sacramento is known, with pride, as the City of Trees. But tree cover isn’t distributed equally there, and neither is exposure to broiling heat. On the northern and southern sides of California’s capital, residents of low-income neighborhoods have long contended with a shortage of shade and green space on sweltering days like last week’s.

Victoria Vasquez is the grants and public policy manager for California ReLeaf, a coalition of nonprofit groups that protect and grow the state’s urban forests. Funding for such work is always tight, Ms. Vasquez said. That hasn’t changed very much even as the West suffers through more and more record temperatures. “I wish that it did,” she said.

Still, she sees signs of movement in the right direction. Sacramento is considering a plan to increase citywide tree cover to 35 percent from 19 percent by 2045. Under the Inflation Reduction Act, the United States Forest Service received $1.5 billion to support urban forest programs.

When neighborhood associations see how quickly they can reap the benefits of planting and maintaining trees, Ms. Vasquez said, “that is an infectious, positive change.”

Sources: U.S.G.S. Landsat via Google Earth Engine; U.S. Census.

Note: Satellite image taken at 11:55 a.m. local time. Higher-uncertainty pixels removed.

In Portland, Ore., tree-filled areas like Forest Park, on the city’s west side, provided oases of cool last week. Yet Vivek Shandas, a professor of urban planning at Portland State University, and his colleagues recently discovered that the city’s overall tree cover decreased somewhat between 2014 and 2020. One likely culprit? Trees are often removed when houses are sold and residential areas redeveloped.

The medical examiner’s office in Multnomah County, which includes Portland, said last week that it was investigating five deaths for links to the recent blistering heat.

In many ways, Portland has become much more attuned to heat threats ever since a heat dome killed hundreds of people in Oregon and Washington in the summer of 2021, Dr. Shandas said. The city is communicating the risks more actively. It has provided portable cooling units to low-income residents. Still missing, Dr. Shandas said, are the changes to building codes and construction practices that would truly ready Portland for the hotter years and decades to come.

“The things that are low-hanging fruit right now, I think have pretty much been picked,” he said. “The longer-term, sustained, deep retrofit that the city needs in order to be prepared for the increasing intensity and frequency of these heat waves? I have yet to see any of that.”

Science

Shark attacks rose in 2025. Here’s why Californians should take note

Published

5 hours ago

February 19, 2026

Press Room

Shark attacks rose in 2025. Here’s why Californians should take note

Shark attacks returned to near-average levels in 2025 after a dip the previous year, according to the latest report from the Florida Museum of Natural History’s International Shark Attack File, published Wednesday.

Researchers recorded 65 unprovoked shark bites worldwide last year, slightly below the 10-year average of 72, but an increase from 2024. Nine of those bites were fatal, higher than the 10-year average of six fatalities.

The United States once again had the highest number of reported incidents, accounting for 38% of global unprovoked bites when assessed on a country by country basis. That said, it’s actually a decline from recent years, including 2024, when more than half of all reported bites worldwide occurred off the U.S. coast.

In 2025, Florida led all states with 11 recorded attacks. California, Hawaii, Texas and North Carolina accounted for the remaining U.S. incidents.

But California stood out in another way: It had the nation’s only unprovoked fatal shark attack in 2025.

A 55-year-old triathlete was attacked by a white shark after entering the water off the coast of Monterey Bay with members of the open-ocean swimming club she co-founded. It was the sole U.S. fatality among 25 reported shark bites nationwide.

It’s not surprising that the sole U.S. shark-related death occurred in California, said Steve Midway, an associate professor of fisheries at Louisiana State University. “In California, you tend to have year-to-year fewer attacks than other places in the U.S. and in the world,” Midway said. “But you tend to have more serious attacks, a higher proportion of fatal attacks.”

The difference lies in species and geography, Midway said. Along the East Coast, particularly in Florida, many bites involve smaller coastal sharks in shallow water, which are more likely to result in nonfatal injuries. California’s deeper and colder waters are home to larger species, such as the great white shark.

“Great whites just happen to be larger,” Midway said. “You’re less likely to be attacked, but if you are, the outcomes tend to be worse.”

Whether measured over 10, 20 or 30 years, average annual shark bite totals globally are actually very stable.

“The global patterns change only slightly from one year to the other,” said Gavin Naylor, director of the Florida Program for Shark Research.

Those annual fluctuations are influenced by a combination of shark biology, ocean conditions and the number of people in the water at any given time in any given place, researchers say.

At the same time, global shark populations remain far below historical levels. Naylor categorizes about 30% of shark species as endangered, largely due to overfishing. In some countries, including the United States and Australia, stronger protections have allowed certain shark populations to recover.

Nevertheless, the risk of being bitten by a shark remains extremely low. The report notes that drowning is a far more common cause of death worldwide — and, if it helps you sleep (or swim), the data show that you are much more likely to be killed by lightning than you are by a shark.

Science

What a Speech Reveals About Trump’s Plans for Nuclear Weapons

Published

5 days ago

February 14, 2026

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What a Speech Reveals About Trump’s Plans for Nuclear Weapons

Within hours of the expiration last week of the final arms control treaty between Moscow and Washington, the State Department sent its top arms diplomat, Thomas G. DiNanno, to Geneva to lay out Washington’s vision for the future. His public address envisioned a future filled with waves of nuclear arms buildups and test detonations.

The views of President Trump’s administration articulated in Mr. DiNanno’s speech represent a stark break with decades of federal policy. In particular, deep in the speech, he describes a U.S. rationale for going its own way on the global ban on nuclear test detonations, which had been meant to curb arms races that in the Cold War had raised the risk of miscalculation, and war.

This annotation of the text of his remarks aims to offer background information on some of the specialized language of nuclear policymaking that Mr. DiNanno used to make his points, while highlighting places where outside experts may disagree with his and the administration’s claims.

What remains unknown is the extent to which Mr. DiNanno’s presentation represents a fixed policy of unrestrained U.S. arms buildups, or more of an open threat meant to spur negotiations toward new global accords on ways to better manage the nuclear age.

Read the original speech.

New York Times Analysis

Established in 1979 as Cold War arsenals grew worldwide, the Conference on Disarmament is a United Nations arms reduction forum made up of 65 member states. It has helped the world negotiate and adopt major arms agreements.

In his State Department role, working under Secretary of State Marco Rubio, Mr. DiNanno is Washington’s top diplomat for the negotiation and verification of international arms accords. Past holders of that office include John Bolton during the first term of the George W. Bush administration and Rose Gottemoeller during Barack Obama’s two terms.

This appears to be referring to China, which has 600 nuclear weapons today. By 2030, U.S. intelligence estimates say it will have more than 1,000.

Here he means Russia, which is conducting tests to put a nuclear weapon into space as well as to develop an underwater drone meant to cross oceans.

New York Times Analysis

« Previous Next »

In this year’s federal budget, the Trump administration is to spend roughly $90 billion on nuclear arms, including basic upgrades of the nation’s arsenal and the replacement of aging missiles, bombers and submarines that can deliver warheads halfway around the globe.

A chief concern of many American policymakers is that Washington will soon face not just a single peer adversary, as in the Cold War, but two superpower rivals, China and Russia.

New York Times Analysis

« Previous Next »

The 1987 Intermediate-Range Nuclear Forces Treaty or I.N.F. banned all weapons capable of traveling between 500 and 5,500 kilometers, or 310 and 3,420 miles, whether armed with nuclear or conventional warheads. The Trump administration is now deploying a number of conventionally armed weapons in that range, including a cruise missile and a hypersonic weapon.

The destructive force of the relatively small Russian arms can be just fractions of the Hiroshima bomb’s power, perhaps making their use more likely. The lesser warheads are known as tactical or nonstrategic nuclear arms, and President Vladimir V. Putin of Russia has repeatedly threatened to use them in Ukraine.

Negotiators of arms control treaties have mostly focused on long-range weapons because the delivery vehicles and their deadly warheads are considered planet shakers that could end civilization.

New York Times Analysis

« Previous Next »

This underwater Russian craft is meant to cross an ocean, detonate a thermonuclear warhead and raise a radioactive tsunami powerful enough to shatter a coastal city.

The nuclear power source of this Russian weapon can in theory keep the cruise missile airborne far longer than other nuclear-armed missiles.

Russia has conducted test launches for placing a nuclear weapon into orbit, which the Biden administration quietly warned Congress about two years ago.

The term refers to the five permanent members of the United Nations Security Council—China, France, Russia, the United Kingdom and the United States.

New York Times Analysis

« Previous Next »

A top concern of American officials is that Beijing and Moscow might form an alliance to coordinate their nuclear forces. Their joint program to develop fuel for atom bombs is seen as an indication of this emerging threat.

This Trump administration plan is dated November but was made public in December.

Released last year, this Chinese government document sought to portray Beijing as a leader in reducing the global threat of nuclear weapons.

Typically, arms control treaties have not required countries to destroy warheads so their keepers put them into storage for possible reuse. The United States retains something on the order of 20,000 small atom bombs meant to ignite the larger blasts of hydrogen bombs.

An imminent surge centers on the nation’s Ohio-class submarines. The Trump administration has called for the reopening of submarine missile tubes that were closed to comply with the New START limits. That will add as many 56 long-range missiles to the fleet. Because each missile can hold multiple arms, the additional force adds up to hundreds more warheads.

This refers to weapons meant for use on a battlefield or within a particular geographic region rather than for aiming at distant targets. It is often seen as synonymous with intermediate-range weapons.

Here, the talk turns to the explosive testing of nuclear weapons for safety, reliability and devising new types of arms. The United States last conducted such a test in 1992 and afterwards adopted a policy of using such nonexplosive means like supercomputer simulations to evaluate its arsenal. In 1996, the world’s nuclear powers signed a global ban on explosive testing. A number of nations, including the United States and China, never ratified the treaty, and it never officially went into force.

In new detail, the talk addresses what Mr. Trump meant last fall when he declared that he had instructed the Pentagon “to start testing our Nuclear Weapons on an equal basis” in response to the technical advances of unnamed foreign states.

Outside experts say the central issue is not whether China and Russia are cheating on the global test ban treaty but whether they are adhering to the U.S. definition. From the treaty’s start in 1996, Washington interpreted “zero” explosive force as the compliance standard but the treaty itself gives no definition for what constitutes a nuclear explosion. Over decades, that ambiguity led to technical disputes that helped block the treaty’s ratification.

By definition, all nuclear explosions are supercritical, which means they split atoms in chain reactions that become self-sustaining in sufficient amounts of nuclear fuel. The reports Mr. DiNanno refers to told of intelligence data suggesting that Russia was conducting a lesser class of supercritical tests that were too small to be detected easily. Russian scientists have openly discussed such small experiments, which are seen as useful for assessing weapon safety but not for developing new types of weapons.

This sounds alarming but experts note that the text provides no evidence and goes on to speak of preparations, not detonations, except in one specific case.

New York Times Analysis

« Previous

The talk gave no clear indication of how the claims about Russian and Chinese nuclear testing might influence U.S. arms policy. But it repeated Mr. Trump’s call for testing “on an equal basis,” suggesting the United States might be headed in that direction, too.

The talk, however, ended on an upbeat but ambiguous note, giving no indication of what Mr. DiNanno meant by “responsible.” Even so, the remark came in the context of bilateral and multilateral actions to reduce the number of nuclear arms in the world, suggesting that perhaps the administration’s aim is to build up political leverage and spur new negotiations with Russia, China or both on testing restraints.

Science

Notoriously hazardous South L.A. oil wells finally plugged after decades of community pressure

Published

5 days ago

February 14, 2026

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Notoriously hazardous South L.A. oil wells finally plugged after decades of community pressure

California Gov. Gavin Newsom announced this week that state oil and gas regulators have permanently closed one of the most infamous drill sites in Los Angeles, bringing an end to a decades-long community campaign to prevent dangerous gas leaks and spills from rundown extraction equipment.

A state contractor plugged all 21 oil wells at the AllenCo Energy drill site in University Park, preventing the release of noxious gases and chemical vapors into the densely populated South Los Angeles neighborhood. The two-acre site, owned by the Archdiocese of Los Angeles, is located across the street from several multifamily apartment buildings and less than 1,000 feet from St. Vincent School.

For years, residents and students had repeatedly complained about acrid odors from the site, with many suffering chronic headaches and nosebleeds. The health concerns prompted a community-driven campaign to shut down the site, with some residents even pleading (unsuccessfully) with the late Pope Francis to intervene.

AllenCo, the site’s operator since 2009, repeatedly flouted environmental regulations and defied state orders to permanently seal its wells.

This month, the California Department of Conservation’s Geologic Energy Management Division (CalGEM) finished capping the remaining unplugged wells with help from Biden-era federal funding.

“This is a monumental achievement for the community who have endured an array of health issues and corporate stalling tactics for far too long,” Newsom said in a statement Wednesday. “I applaud the tireless work of community activists who partnered with local and state agencies to finish the job and improve the health and safety of this community. This is a win for all Californians.”

The land was donated to the Catholic Archdiocese of Los Angeles in the 1950s by descendants of one of the city’s early oil barons. Over the decades, the archdiocese leased the land to several oil companies including Standard Oil of California.

Much of the community outcry over the site’s management occurred after AllenCo took over the site in 2009. The company drastically boosted oil production, but failed to properly maintain its equipment, resulting in oil spills and gas leaks.

In 2013, U.S. Environmental Protection Agency officials became sick while inspecting the site. The federal investigators encountered puddles of crude oil on the facility grounds, as well as caustic fumes emanating from the facility, resulting in violations for air quality and other environmental infractions.

In 2020, CalGEM ordered AllenCo to plug the wells after if determined the company had essentially deserted the site, leaving the wells unplugged and in an unsafe condition. AllenCo ignored the order.

In perhaps the most remarkable events in the site’s history, CalGEM officials in 2022 arrived on the site with a court order and used bolt cutters to enter the site to depressurize the poorly maintained oil wells.

The AllenCo wells were prioritized and plugged this week as part of a CalGEM program to identify and permanently cap high-risk oil and gas wells. Tens of thousands of unproductive and unplugged oil wells have been abandoned across California — many of which continue to leak potentially explosive methane or toxic benzene.

Environmental advocates have long fought for regulators to require oil and gas companies to plug these wells to protect nearby communities and the environment.

However, as oil production declines and fossil fuel companies increasingly become insolvent, California regulators worry taxpayers may have to assume the costs to plug these wells. Federal and state officials have put aside funding to deal with some of these so-called “orphaned” wells, but environmental advocates say it’s not enough. They say oil and gas companies still need to be held to account, so that the same communities that were subjected to decades of pollution won’t have to foot the bill for expensive cleanups.

“This is welcome news that the surrounding community deserves, but there is much more work to be done at a much faster pace,” said Cooper Kass, attorney at the Center for Biological Diversity’s Climate Law Institute. “There are still thousands of unplugged and hazardous idle wells threatening communities across the state, and our legislators and regulators should force polluters, not taxpayers, to pay to clean up these dangerous sites.”