On Tuesday, Make Sunsets announced it had completed three balloon launches near Reno, Nevada, each of which contained less than 10 grams of sulfur dioxide, which is the most commonly sited aerosol particle discussed in conversations about solar geoengineering. Two of the balloons launched also had location trackers, and one had a camera, too.
The idea of solar geoengineering has been around for decades and generally refers to spraying aerosol particles into the upper atmosphere in order to reflect the sun’s rays away from earth and back to space, cooling the earth and temporarily mitigating the effects of climate change.
Essentially, solar geoengineering is mimicking what happens when a volcano erupts, and it’s known to work. When Mount Pinatubo in the Philippines released thousands of tons of sulfur dioxide into the stratosphere in the 1991 eruption, the global temperature of the earth was lowered on average by about 1 degree Fahrenheit, according to the U.S. Geological Survey.
Solar geoengineering is not a solution to climate change, and nobody who studies it rigorously suggests it should be. It’s a temporary stopgap measure.
In addition, while releasing sulfur dioxide particles will cool the earth quickly and relatively inexpensively, it’s also dangerous. Injecting sulfur dioxide into the atmosphere could damage the ozone layer, cause respiratory illness and create acid rain.
But as the effects of climate change become more obvious, people are beginning to take the idea more seriously.
The White House is coordinating a five-year research plan into solar geoengineering, the quadrennial U.N.-backed Montreal Protocol assessment report included an entire chapter addressing stratospheric aerosol injection (more colloquially called solar geoengineering), and Dustin Moskovitz, a co-founder of Facebook, is funding solar geoengineering research via his philanthropic organization, Open Philanthropy.
While momentum is building, there isn’t any international governance rules about how to study and potentially regulate the idea.
Luke Iseman, a serial inventor and the former director of hardware at Y Combinator, launched Make Sunsets in October in an effort to push that envelope. San Mateo-headquartered venture capital firm BoostVC invested $500,000 in the startup and Iseman brought in a co-founder, Andrew Song.
The launches in Nevada earlier in February occurred at the Rancho San Rafael Regional Park in Reno, , where an annual hot-air balloon festival takes place, Iseman told CNBC.
They chose Nevada “because it’s in the U.S., we’re very confident we know and followed all applicable rules, know the terrain well from past adventures, and, we didn’t want to interfere with a friend’s efforts to get a marine cloud brightening project permitted in California,” Iseman told CNBC.
The Nevada launch was previously detailed by Time reporters, who were there. It was a shoe-string MacGyver-ed event orchestrated out of a hotel room, with a grill and weather balloon equipment. But, as evidenced by the images embedded below, shared with CNBC by Make Sunsets, the balloons lifted off.
Make Sunsets team is filling sulfur dioxide in a bag preparing for launch.
Photo courtesy Make Sunsets
Make Sunsets team is weighing the bag filled with sulfur dioxide gas in a bag preparing for launch.
Photo courtesy Make Sunsets
Make Sunsets is filling the balloon with helium here.
Photo courtesy Make Sunsets
Here, founder Luke Iseman is preparing to release the weather balloon filled with sulfur dioxide and helium into the atmosphere. Make Sunsets says this is the first deployment of SAI, or stratospheric aerosol injection, another and more specific name for solar geoengineering.
Photo courtesy Make Sunsets
Luke Iseman, the founder of Make Sunsets, is about to launch a weather balloon filled with sulfur dioxide and helium into the air in Nevada.
Photo courtesy Make Sunsets
Make Sunsets launching a weather balloon filled with sulfur dioxide and helium into the air in Nevada.
Photo courtesy Make Sunsets
A view from the Make Sunsets balloon launched in Nevada.
Photo courtesy Make Sunsets
A view from the Make Sunsets balloon launched in Nevada.
Photo courtesy Make Sunsets
Iseman has both idealistic and practical goals.
“Most importantly: We need to cool earth to save millions of lives, hundreds of thousands of species, and buy the time we need to decarbonize,” Iseman told CNBC.
To make the business sustainable, Make Sunsets is selling cooling credits, which gives companies and individuals a way to offset the effects of their carbon emissions. But the startup has yet to deliver.
“We have 2,790 cooling credits ordered by 58 paying customers that we haven’t yet delivered,” Iseman told CNBC. “On one hand, we’re working hard on a controversial project to cool earth. On the other, we’re a startup with the same basic challenge as any other: get customers to pay more for what we’re selling than it costs to make it.”
Make Sunsets said it made the FAA aware that it was releasing a balloon.
The FAA provided the following statement: “The FAA has comprehensive regulations for safely operating unmanned free balloons. Among other things, the regulations require the balloon to be equipped so it can be tracked by radar, and the operator to notify the FAA prior to and at the time of launch, monitor and record the balloon’s course, make position reports to the FAA as requested, and notify the FAA when the balloon begins its descent and its expected trajectory.”
Correction: A previous version of this story misstated what the balloons contained. All three of them had sulfur dioxide.
Apple’s iPhone 16 at an Apple Store on Regent Street in London on Sept. 20, 2024.
Rasid Necati Aslim | Anadolu | Getty Images
Apple has made moves to diversify its supply chain beyond China to places like India and Vietnam, but tariffs announced by the White House are set to hit those countries too.
China will face a 34% tariff, but with the existing 20% rate, that brings the true tariff rate on Beijing under this Trump term to 54%, CNBC reported. India faces a 26% tariff, while Vietnam’s rate is 46%.
Apple was not immediately available for comment when contacted by CNBC.
Here’s a breakdown on Apple’s supply chain footprint that could be affected by tariffs.
China
The majority of Apple’s iPhones are still assembled in China by partner Foxconn.
China accounts for around 80% of Apple’s production capacity, according to estimates from Evercore ISI in a note last month.
Around 90% of iPhones are assembled in China, Evercore ISI said.
While the number of manufacturing sites in China dropped between Apple’s 2017 and 2020 fiscal year, it has since rebounded, Bernstein said in a note last month. Chinese suppliers account for around 40% of Apple’s total, Bernstein said.
Evercore ISI estimates that 55% of Apple’s Mac products and 80% of iPads are assembled in China.
India
Apple is targeting around 25% of all iPhones globally to be made in India, a government minister said in 2023.
India could reach about 15%-20% of overall iPhone production by the end of 2025, Bernstein analysts estimate. Evercore ISI said around 10% to 15% of iPhones are currently assembled in India.
Vietnam
Vietnam has emerged in the past few years as a popular manufacturing hub for consumer electronics. Apple has increased its production in Vietnam.
Around 20% of iPad production and 90% of Apple’s wearable product assembly like the Apple Watch takes place in Vietnam, according to Evercore ISI.
Other key countries
Malaysia is a growing manufacturing location for Apple for Macs and is facing a 25% tariff. Thailand is also a small hub for Mac production and will be hit with a 36% levy.
Apple also sources components from South Korea, Japan, Taiwan and the United States. Components may be shipped from one country to another before assembly takes place in China or elsewhere.
In February, Apple announced plans to open a new factory for artificial intelligence servers in Texas as part of a $500 billion investment in the U.S.
However, Apple does not have mass production in the United states. It produces only the Mac Pro in Texas.
A Xiaomi store in Shanghai, China, on March 16, 2025.
Qilai Shen/Bloomberg | Bloomberg | Getty Images
Chinese electric carmakers Xiaomi, Xpeng and Leapmotor each delivered nearly 30,000 or more cars in March, roughly twice several of their fellow startup competitors.
It’s a sign of how some automakers are pulling ahead, while BYD remains the market leader by far.
Xiaomi delivered a record number of electric vehicles in March, exceeding 29,000 units, the company announced on social media. That topped its prior run of delivering more than 20,000 vehicles in each of the past five months.
The SU7, Xiaomi’s flagship model, was involved in a crash on a highway on Tuesday that left three dead. The automaker on Tuesday afternoon released a statement on Chinese social media that the vehicle was in navigation on autopilot mode before the accident.
Based on preliminary information, the road was obstructed because of construction. The driver took control of the car but collided with construction infrastructure. Xiaomi added in the release that investigations were underway.
That came two weeks after the automaker announced on March 18 its goal to deliver 350,000 vehicles this year. There are also talks of the automaker expanding its second EV factory in Beijing to meet demand, Bloomberg reported on March 18. Xiaomi did not immediately respond to CNBC’s request for comment.
Its competitor Xpeng in March delivered 33,205 vehicles, the fifth consecutive month it has delivered over 30,000 units per month and reflecting a 268% surge in deliveries from the same month last year. March is also the fifth consecutive month the company has delivered over 15,000 units of the Mona M03.
Li Autodelivered 36,674 vehicles in March, a 26.5% year-over-year increase, but fewer than every month in the second half of 2024. The company’s cars had gained early traction with Chinese consumers since most come with a fuel tank for charging the vehicle’s battery, reducing anxiety about driving range.
BYD sold 371,419 passenger vehicles in March, reflecting a year-over-year growth of 57.9%. Its overseas sales volume also hit a record high of 72,723 units in March.
Across the board, major companies across China’s electric car industry reported deliveries rose last month, indicating a pick-up in demand from the seasonally soft first two months of the year.
U.S. automaker Tesla sold 78,828 electric vehicles in China in March, marking a 11.5% year-over-year decline in growth.
Other Chinese carmakers saw growth in deliveries but some still struggled to break through the 20,000-unit mark.
Niodelivered 15,039 vehicles, a 26.7% year-over-year growth, but well below the number of cars delivered in the months of May to December last year. Nio-owned Onvo, which markets its electric vehicles as family-oriented, in March recorded 15,039 units in deliveries.
Aito, as of April 2, has not published its delivery numbers for March. The automaker, which uses Huawei tech in its vehicles, on social media had reported monthly deliveries of 34,987 and 21,517 in January and February, respectively.
Quarterly performance
On a first-quarter basis, BYD remained in the lead with 986,098 vehicles sold. The automaker, which overtook Tesla in annual sales last year, surpassed the U.S. EV giant in battery electric vehicles sales this quarter.
Tesla sold 172,754 vehicles in China in the first quarter this year, according to monthly delivery numbers published by the China Passenger Car Association.
Xpeng also reported strong growth, with a total of 94,008 vehicles delivered in the quarter ending in March, reflecting a 331% year-over-year growth.
Leapmotor saw quarterly deliveries more than double to 87,552 units from 33,410 units the same period in 2024, according to publicly available numbers the company published.
However, Li Auto and Nio reported weaker growth than their competitors in the first quarter of the year.
Nio saw 42,094 vehicles delivered in the three months ended March 2025, an increase of 40.1% year over year. Li Auto saw a slower year-over-year growth of 15.5%, with a total of 92,864 vehicles delivered.
Wednesday’s announcement, which came alongside a set of sweeping new tariffs, gives customs officials, retailers and logistics companies more time to prepare. Goods that qualify under the de minimis exemption will be subject to a duty of either 30% of their value, or $25 per item. That rate will increase to $50 per item on June 1, the White House said.
Use of the de minimis provision has exploded in recent years as shoppers flock to Chinese e-commerce companies Temu and Shein, which offer ultra-low cost apparel, electronics and other items. The U.S. Customs and Border Protection has said it processed more than 1.3 billion de minimis shipments in 2024, up from over 1 billion shipments in 2023.
Critics of the provision say it provides an unfair advantage to Chinese e-commerce companies and creates an influx of packages that are “subject to minimal documentation and inspection,” raising concerns around counterfeit and unsafe goods.
The Trump administration has sought to close the loophole over concerns that it facilitates shipments of fentanyl and other illicit substances on the claims that the packages are less likely to be inspected by customs agents.
Temu and Shein have taken steps to grow their operations in the U.S. as the de minimis loophole has come under greater scrutiny. After onboarding sellers with inventory in U.S. warehouses, Temu recently began steering shoppers to those items on its website, allowing it to speed up deliveries. Shein opened distribution centers in states including Illinois and California in 2022, and a supply chain hub in Seattle last year.