Green Daily

Today’s newsletter looks at the latest data from Bloomberg’s London Tube Heat Index, which was launched by our weather and climate reporter Joe Wertz at the start of summer. It shows a popular weekday journey from the financial center has stayed within heat wave conditions every day since he started recording. You can read and share this story with your friends and followers on Bloomberg.com.

The Underground heat wave

By Joe Wertz, Olivia Rudgard and Siobhan Wagner

A quiet threat to London’s position as a bustling world financial center is starting to show on the sweaty white collars of the city’s commuters.

The ride on the deepest lines in London’s Underground system, always something of a chore, is becoming closer to unbearable for travelers to the city’s main deal-making district. Financial workers this summer are being asked to return to the office up to five days a week at a time when soaring temperatures are making many un-airconditioned transport links in London feel woefully unprepared for climate change.

“It hurts the idea of going into the office, because you'll be sweating no matter what you’re wearing,” said Tom Mulinder, who works in construction finance and commutes to the City of London from the suburbs in Surrey, some 30 miles away.

After registering the hottest June on record, England experienced three heat waves before the end of July. Below ground, however, weekday commuters have been facing the equivalent of nonstop heat wave conditions all summer, data recorded by Bloomberg News show.

Temperatures inside the crowded carriages are several degrees hotter than the surface, according to Bloomberg’s London Tube Heat Index, which, since June 23, has been tracking temperatures on the Central line from Bank station in the financial district to Bond Street in the posh Mayfair neighborhood. The journey covers about 10 minutes a little before 4 p.m. each day.

Temperatures can climb quickly, routinely reaching 31C (88 F) for several days in a row, well above the UK Met Office’s heat wave threshold of three consecutive days of 28C or higher. Even when the weather shifts, London’s Underground is slow to cool. During a rain shower on Thursday when surface temperatures were 23.6C, the Central line commute averaged 29.3C, nearly 6 degrees warmer.

The heat is worsened by 40% humidity and poor air flow: On the Central line, the hottest afternoon commutes are also the stuffiest, according to the Bloomberg data, which also records CO2 levels to estimate ventilation.

“London was built by the Victorians for a Victorian climate, and now we have a different climate,” said Bob Ward, chair of the London Climate Ready Partnership, a network of experts and public authorities seeking to improve London’s climate resilience. That’s a problem for a city that lives or dies on its ability to draw workers. “If [London] becomes perceived as too risky, people won’t want to live and work here, and it will actually hit its ability to attract talented people.”

Want to know more about what makes the London Underground so hot? Read the full story on Bloomberg.com — and for unlimited access to climate and energy news, please subscribe.

Cool costs

£2.9 billion

This is how much is being spent on a program to upgrade London's Piccadilly line, one of the older, deep underground routes. Its new carriages will be fitted with air conditioning.

Staying home

"If this carries on and London settles at a new normal of office working below what is standard in other places, then it might lose its international competitive edge."

Rob Johnson

Analyst at the Centre for Cities, a London-based think tank

In the post-pandemic era, Londoners have been more reluctant to go back to the office than their counterparts in Paris, Singapore and New York, according to a study Johnson carried out last year. The heat only adds to the hassle, he said.

More from Green

The world’s oceans experienced a staggering amount of warming in 2023, as vast marine heat waves affected 96% of their surface, breaking records for intensity, longevity and scale, according to a new study.

That could mark a turning point in the way the oceans behave, potentially signaling a tipping point after which average sea temperatures will be reset higher and some ecosystems may not recover, say the authors of the study, which was published Thursday in the journal Science.

“The ocean going to a new normal — that controls everything,” said Zhenzhong Zeng, an Earth systems scientist at China’s Southern University of Science and Technology, who led the work. “Once we destroy it, then maybe it cannot go back.”

Australian utilities are turning to floating solar installations on lakes and reservoirs to reduce water loss through evaporation. Covering around 70% of a reservoir with floating panels can reduce evaporation by 55%, according to Canopy Power.

Chinese solar manufacturers are assembling equipment in Indonesia and exporting products to the US tariff-free, according to Bloomberg News analysis of trade and corporate records.

Companies canceled, closed or scaled back more than $22 billion worth of investments in clean-energy projects during the first half of this year ahead of President Trump’s signing of a tax bill that rolls back Biden-era green tax breaks.

Washington diary

A tally of recent events you may have missed on changes impacting climate policy and science under the Trump administration.

A new Trump executive order would aim to roll back regulations, including environmental standards, that slow artificial intelligence development. The mandate comes as the rush to build up AI infrastructure has raised climate concerns over data centers’ enormous requirements for energy, which may come from fossil fuel sources.

The AI Action Plan also recommends the federal government only award contracts to developers whose AI models are free of "ideological bias," and to strip climate change references from risk-management frameworks, along with misinformation, diversity and equity language. "[W]e will continue to reject radical climate dogma and bureaucratic red tape," the order says.

The US Environmental Protection Agency is considering scrapping a bedrock finding that greenhouse gas emissions are harmful to human health, the Washington Post reported, citing two sources familiar with the details.

Late last week, the EPA shuttered its Office of Research and Development, NPR reported. The office provided environmental health research needed to make regulations that keep people and ecosystems safe from pollutants. A new office will be created to prioritize research and science, the EPA said in a statement. --Danielle Bochove

What did we miss this week in Washington? Email dbochove1@bloomberg.net

Worth a listen

The One Big Beautiful Bill has cut an estimated $500 billion in green spending, but the Trump administration policy that worries venture capitalist Vinod Khosla more for climate tech in the US is immigration. “They will shut down the import of talent, which is the key to growth,” he told the Zero podcast on stage at the Bloomberg Green summit in Seattle, Washington last week.

Khosla said the “hostile environment” may even turn off those who are able to enter the US. “So we will reduce talented immigration of PhDs and people equipped to solve climate and other technology problems into this country, unfortunately,” he said.

In a wide-ranging interview, Khosla also explained whether he’s reconsidering investing in the US and when we can expect to see fusion. Listen now, and subscribe on Apple, Spotify, or YouTube to get new episodes of Zero every Thursday.