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The White House is coordinating a five-year research plan to study ways of modifying the amount of sunlight that reaches the earth to temper the effects of global warming, a process sometimes called solar geoengineering or sunlight reflection.

The research plan will assess climate interventions, including spraying aerosols into the stratosphere to reflect sunlight back into space, and should include goals for research, what’s necessary to analyze the atmosphere, and what impact these kinds of climate interventions may have on the Earth, according to the White House‘s Office of Science and Technology Policy. Congress directed the research plan be produced in its spending plan for 2022, which President Joe Biden signed in March.

Some of the techniques, such as spraying sulfur dioxide into the atmosphere, are known to have harmful effects on the environment and human health. But scientists and climate leaders who are concerned humanity will overshoot its emissions targets say research is important to figure out how to balance these risks against a possibly catastrophic rise in the earth’s temperature.

Getting ready to research a topic is a very preliminary step, but it’s notable the White House is formally engaging with what has largely been seen as the stuff of dystopian fantasy. In Kim Stanley Robinson’s science fiction novel, “The Ministry for the Future,” a heatwave in India kills 20 million people and out of desperation, India decides to implement its own strategy of limiting the sunlight that gets to earth.

Chris Sacca, the founder of climate tech investment fund Lowercarbon Capital, says it’s prudent for the White House to be spearheading the research effort.

“Sunlight reflection has the potential to safeguard the livelihoods of billions of people, and it’s a sign of the White House’s leadership that they’re advancing the research so that any future decisions can be rooted in science not geopolitical brinkmanship,” Sacca told CNBC. (Sacca has donated to support research in the area, but has “zero financial interests beyond philanthropy” in the idea and does not think there should be private business models in the space, he told CNBC.)

Harvard professor David Keith first worked on the topic in 1989, and says it’s being taken much more seriously now. He points to a formal statement of support for research from a group he advises called the Overshoot Commission. The Environmental Defense Fund, the Union of Concerned Scientists, and the Natural Resources Defense Council have also indicated support for research into the topic.

To be clear, nobody is saying sunlight reflection modification is the solution to climate change. Reducing emissions remains the priority.

“You cannot judge what the country does on solar radiation modification without looking at what it is doing in emission reductions, because the priority is emission reductions,” said Janos Pasztor, the executive director of the Carnegie Climate Governance Initiative. “Solar radiation modification will never be a solution to the climate crisis.”

Three ways to reduce sunlight

The idea of sunlight reflection first appeared prominently in a 1965 report to President Lyndon B. Johnson entitled “Restoring the Quality of Our Environment,” Keith told CNBC. The report floated the idea of spreading particles over the ocean at a cost of $100 per square mile. A one percent change in the reflectivity of the earth would cost $500 million per year, which does “not seem excessive,” the report says, “considering the extraordinary economic and human importance of climate.”

The estimated price tag has gone up since then. The current estimate is that it would cost $10 billion per year to run a program that cools the earth by one degree Celsius, said Edward A. Parson, a professor of environmental law at UCLA’s law school. But that is remarkably cheap compared to other climate change mitigation efforts.

A landmark report released in March 2021 from the National Academies of Sciences, Engineering, and Medicine addressed three kinds of solar geoengineering: stratospheric aerosol injection, marine cloud brightening, and cirrus cloud thinning.

Stratospheric aerosol injection would involve flying aircraft into the stratosphere, which is between 10 and 30 miles up, and spraying a fine mist that would hang in the air, reflecting some of the sun’s radiation back into space.

“The stratosphere is calm, and things stay up there for a long time,” Parson told CNBC. “The atmospheric life of stuff that’s injected in the stratosphere is between six months and two years.”

Stratospheric aerosol injection “would immediately take the high end off hot extremes,” Parson said. And also it would “pretty much immediately” slow extreme precipitation events too, he said.

“The top line slogan about stratospheric aerosol injection, which I wrote in a paper more than 10 years ago — but it’s still apt — is fast, cheap, and imperfect. Fast is crucial. Nothing else that we do for climate change is fast. Cheap, it’s so cheap,” Parson told CNBC.

“And it’s not imperfect because we haven’t got it right yet. It’s imperfect because the imperfection is embedded in the way it works. The same reason it’s fast is the reason that it’s imperfect, and there’s no way to get around that.”

One option for an aerosol is sulfur dioxide, the cooling effects of which are well known from volcanic eruptions. The 1991 eruption of Mount Pinatubo, for instance, spewed thousands of tons of sulfur dioxide into the stratosphere, causing global temperatures to drop temporarily by about 1 degree Fahrenheit, according to the U.S. Geological Survey.

A giant volcanic mushroom cloud explodes some 20 kilometers high from Mount Pinatubo above almost deserted US Clark Air Base, on June 12, 1991 followed by another more powerful explosion. The eruption of Mount Pinatubo on June 15, 1991 was the second largest volcanic eruption of the twentieth century.

Arlan Naeg | Afp | Getty Images

There’s also a precedent in factories that burn fossil fuels, especially coal. Coal has some sulfur that oxidizes when burns, creating sulfur dioxide. That sulfur dioxide goes through other chemical reactions and eventually falls to the earth as sulfuric acid in rain. But, during the time that the sulfur pollution sits in the air, it does serve as a kind of insulation from the heat of the sun.

Ironically, as the world reduces coal burning to curb the carbon dioxide emissions that cause global warming, we’ll also be eliminating the sulfur dioxide emissions that mask some of that warming.

“Sulfur pollution that’s coming out of smokestacks right now is masking between a third and a half of the heating signal from the greenhouse gases humans have already emitted into the atmosphere,” Parson said.

In other words, we’ve been doing one form of sunlight reflection for decades already, but in an uncontrolled fashion with terrible warming effects, explains Kelly Wanser, the executive director of SilverLining, an organization promoting research and governance of climate interventions.

“This isn’t something totally new and Frankenstein — we’re already doing it; we’re doing it in the most dirty, unplanned way you could possibly do it, and we don’t understand what we’re doing,” Wanser told CNBC. 

Spraying sulfur in the stratosphere is not the only way of manipulating the amount of sunlight that gets to the earth, and some say it’s not the best option.

“Sulfur dioxide is likely not the best aerosol and is by no means the only technique for this. Cloud brightening is a very promising technique as well, for example,” Sacca told CNBC.

Marine cloud brightening involves increasing the reflectivity of clouds that are relatively close to the surface of the ocean with techniques like spraying sea salt crystals into the air. Marine cloud brightening generally gets less attention than stratospheric aerosol injection because it affects a half dozen to a few dozen miles and would potentially only last hours to days, Parson told CNBC.

Cirrus cloud thinning, the third category addressed in the 2021 report from the National Academies, involves thinning mid-level clouds, between 3.7 and 8.1 miles high, to allow heat to escape from the surface of the earth. It is not technically part of the “solar geoengineering” umbrella category because it does not involve reflecting sunlight, but instead involves increasing the release of thermal radiation.

Known risks to people and the environment

There are significant and well-known risks to some of these techniques — sulfur dioxide aerosol injection in particular.

First, spraying sulfur into the atmosphere will “mess with the ozone chemistry in a way that might delay the recovery of the ozone layer,” Parson told CNBC.

The Montreal Protocol adopted on September 16, 1987, regulates and phases out the use of ozone depleting substances, such as hydrochlorofluorocarbons (HCFCs) which were commonly used in refrigeration and air conditioners, but that healing process is still ongoing.

Also, sulfates injected into the atmosphere eventually come down as acid rain, which affects soil, water reservoirs, and local ecosystems.

Thirdly, the sulfur in the atmosphere forms very fine particulates that cause respiratory illness.

The question, then, is whether these known effects are more or less harmful than the warming they would offset.

“Yes, damaging the ozone is bad, acid deposition is bad, respiratory illness is bad, absolutely. And spraying sulfur in the stratosphere would contribute in the bad direction to all of those effects,” Parson told CNBC. “But you also have to ask, how much and relative to what?”

The sulfur already being emitted from the burning of fossil fuels is already causing environmental damage and is already killing between 10 and 20 million people a year due to respiratory illness, said Parson. “So that’s the way we live already,” he said.

Meanwhile, “the world is getting hotter, and there will be catastrophic impacts for many people in the world,” said Pasztor.

“There’s already too much carbon out there. And even if you stop all emissions today, the global temperature will still be high and will remain high for hundreds of years. So that’s why scientists are saying maybe we need something else, in addition — not instead of — but maybe in addition to everything else that is being done,” he said. “The current action/non action of countries collectively — we are committing millions of people to death. That’s what we’re doing.”

For sunlight reflection technology to become a tool in the climate change mitigation toolbox, awareness among the public and lawmakers has to grow slowly and steadily, according to Tyler Felgenhauer, a researcher at Duke University who studies public policy and risk.

“If it is to rise onto the agenda, it’ll be kind of an evolutionary development where more and more environmental groups are willing to state publicly that they’re for research,” Felgenhauer told CNBC. “We’re arguing it’s not going to be some sort of one big, bad climate event that makes us all suddenly adopt or be open to solar geoengineering — there will be more of a gradual process.”

A man waits for customers displaying fans at his store amid rising temperatures in New Delhi on May 27, 2020. – India is wilting under a heatwave, with the temperature in places reaching 50 degrees Celsius (122 degrees Fahrenheit) and the capital enduring its hottest May day in nearly two decades.

Jewel Samad | Afp | Getty Images

Research it now or be caught off guard later?

Some environmentalists consider sunlight relfection a “moral hazard,” because it offers a relatively easy and inexpensive alternative to doing the work of reducing emissions.

One experiment to study stratospheric aerosols by the Keutsch Group at Harvard was called off in 2021 due to opposition. The experiment would have “threaten the reputation and credibility of the climate leadership Sweden wants and must pursue as the only way to deal effectively with the climate crisis: powerful measures for a rapid and just transition to zero emission societies, 100% renewable energy and shutdown of the fossil fuel industry,” an open letter from opponents said.

But proponents insist that researching sunlight modification technologies should not preclude emissions reduction work.

“Even the people like me who think it’s very important to do research on these things and to develop the capabilities all agree that the urgent top priority for managing climate change is cutting emissions,” Parson told CNBC.

Keith of Harvard agrees. His goal is “simply that we learn more and develop better mechanism[s] for governance,” he told CNBC.

Doing research is also important because many onlookers expect that some country, facing an unprecedented climate disaster, will act unilaterally to will try some version of sunlight modification anyway — even if it hasn’t been carefully studied.

“In my opinion, it’s more than 90 percent likely that within the next 20 years, some major nation wants to do this,” Parson said.

Sacca put the odds even higher.

“The odds are 100 percent that some country pursues sunlight reflection, particularly in the wake of seeing millions of their citizens die from extreme weather,” Sacca told CNBC. “The world will not stand idly by and leaders will feel compelled to take action. Our only hope is that by doing the research now, and in public, the world can collaboratively understand the upsides and best methods for any future project.”  

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Nvidia CEO downplays U.S. fears that China’s military will use his firm’s chips

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Nvidia CEO downplays U.S. fears that China's military will use his firm's chips

Co-founder and chief executive officer of Nvidia Corp., Jensen Huang attends the 9th edition of the VivaTech trade show in Paris on June 11, 2025.

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Nvidia CEO Jensen Huang has downplayed U.S. fears that his firm’s chips will aid the Chinese military, days ahead of another trip to the country as he attempts to walk a tightrope between Washington and Beijing. 

In an interview with CNN aired Sunday, Huang said “we don’t have to worry about” China’s military using U.S.-made technology because “they simply can’t rely on it.”

“It could be limited at any time; not to mention, there’s plenty of computing capacity in China already,” Huang said. “They don’t need Nvidia’s chips, certainly, or American tech stacks in order to build their military,” he added.

The comments were made in reference to years of bipartisan U.S. policy that placed restrictions on semiconductor companies, prohibiting them from selling their most advanced artificial intelligence chips to clients in China. 

Huang also repeated past criticisms of the policies, arguing that the tactic of export controls has been counterproductive to the ultimate goal of U.S. tech leadership. 

“We want the American tech stack to be the global standard … in order for us to do that, we have to be in search of all the AI developers in the world,” Huang said, adding that half of the world’s AI developers are in China. 

‘The Nvidia Way’ author Tae Kim: Jensen Huang always positions Nvidia ahead of the next big trend

That means for America to be an AI leader, U.S. technology has to be available to all markets, including China, he added.

Washington’s latest restrictions on Nvidia’s sales to China were implemented in April and are expected to result in billions in losses for the company. In May, Huang said chip restrictions had already cut Nvidia’s China market share nearly in half.

Huang’s CNN interview came just days before he travels to China for his second trip to the country this year, and as Nvidia is reportedly working on another chip that is compliant with the latest export controls.

Last week, the Nvidia CEO met with U.S. President Donald Trump, and was warned by U.S. lawmakers not to meet with companies connected to China’s military or intelligence bodies, or entities named on America’s restricted export list.

According to Daniel Newman, CEO of tech advisory firm The Futurum Group, Huang’s CNN interview exemplifies how Huang has been threading a needle between Washington and Beijing as it tries to maintain maximum market access.

“He needs to walk a proverbial tightrope to make sure that he doesn’t rattle the Trump administration,” Newman said, adding that he also wants to be in a position for China to invest in Nvidia technology if and when the policy provides a better climate to do so.

But that’s not to say that his downplaying of Washington’s concerns is valid, according to Newman. “I think it’s hard to completely accept the idea that China couldn’t use Nvidia’s most advanced technologies for military use.”

He added that he would expect Nvidia’s technology to be at the core of any country’s AI training, including for use in the development of advanced weaponry. 

A U.S. official told Reuters last month that China’s large language model startup DeepSeek — which says it used Nvidia chips to train its models — was supporting China’s military and intelligence operations. 

On Sunday, Huang acknowledged there were concerns about DeepSeek’s open-source R1 reasoning model being trained in China but said that there was no evidence that it presents dangers for that reason alone.

Huang complimented the R1 reasoning model, calling it “revolutionary,” and said its open-source nature has empowered startup companies, new industries, and countries to be able to engage in AI. 

“The fact of the matter is, [China and the U.S.] are competitors, but we are highly interdependent, and to the extent that we can compete and both aspire to win, it is fine to respect our competitors,” he concluded. 

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Google hires Windsurf CEO Varun Mohan, others in latest AI talent deal

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Google hires Windsurf CEO Varun Mohan, others in latest AI talent deal

Chief executive officer of Google Sundar Pichai.

Marek Antoni Iwanczuk | Sopa Images | Lightrocket | Getty Images

Google on Friday made the latest a splash in the AI talent wars, announcing an agreement to bring in Varun Mohan, co-founder and CEO of artificial intelligence coding startup Windsurf.

As part of the deal, Google will also hire other senior Windsurf research and development employees. Google is not investing in Windsurf, but the search giant will take a nonexclusive license to certain Windsurf technology, according to a person familiar with the matter. Windsurf remains free to license its technology to others.

“We’re excited to welcome some top AI coding talent from Windsurf’s team to Google DeepMind to advance our work in agentic coding,” a Google spokesperson wrote in an email. “We’re excited to continue bringing the benefits of Gemini to software developers everywhere.”

The deal between Google and Windsurf comes after the AI coding startup had been in talks with OpenAI for a $3 billion acquisition deal, CNBC reported in April. OpenAI did not immediately respond to a request for comment.

The move ratchets up the talent war in AI particularly among prominent companies. Meta has made lucrative job offers to several employees at OpenAI in recent weeks. Most notably, the Facebook parent added Scale AI founder Alexandr Wang to lead its AI strategy as part of a $14.3 billion investment into his startup. 

Douglas Chen, another Windsurf co-founder, will be among those joining Google in the deal, Jeff Wang, the startup’s new interim CEO and its head of business for the past two years, wrote in a post on X.

“Most of Windsurf’s world-class team will continue to build the Windsurf product with the goal of maximizing its impact in the enterprise,” Wang wrote.

Windsurf has become more popular this year as an option for so-called vibe coding, which is the process of using new age AI tools to write code. Developers and non-developers have embraced the concept, leading to more revenue for Windsurf and competitors, such as Cursor, which OpenAI also looked at buying. All the interest has led investors to assign higher valuations to the startups.

This isn’t the first time Google has hired select people out of a startup. It did the same with Character.AI last summer. Amazon and Microsoft have also absorbed AI talent in this fashion, with the Adept and Inflection deals, respectively.

Microsoft is pushing an agent mode in its Visual Studio Code editor for vibe coding. In April, Microsoft CEO Satya Nadella said AI is composing as much of 30% of his company’s code.

The Verge reported the Google-Windsurf deal earlier on Friday.

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Google pushes "AI Mode" on homepage

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Nvidia’s Jensen Huang sells more than $36 million in stock, catches Warren Buffett in net worth

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Nvidia's Jensen Huang sells more than  million in stock, catches Warren Buffett in net worth

Jensen Huang, CEO of Nvidia, holds a motherboard as he speaks during the Viva Technology conference dedicated to innovation and startups at Porte de Versailles exhibition center in Paris, France, on June 11, 2025.

Gonzalo Fuentes | Reuters

Nvidia CEO Jensen Huang unloaded roughly $36.4 million worth of stock in the leading artificial intelligence chipmaker, according to a U.S. Securities and Exchange Commission filing.

The sale, which totals 225,000 shares, comes as part of Huang’s previously adopted plan in March to unload up to 6 million shares of Nvidia through the end of the year. He sold his first batch of stock from the agreement in June, equaling about $15 million.

Last year, the tech executive sold about $700 million worth of shares as part of a prearranged plan. Nvidia stock climbed about 1% Friday.

Huang’s net worth has skyrocketed as investors bet on Nvidia’s AI dominance and graphics processing units powering large language models.

The 62-year-old’s wealth has grown by more than a quarter, or about $29 billion, since the start of 2025 alone, based on Bloomberg’s Billionaires Index. His net worth last stood at $143 billion in the index, putting him neck-and-neck with Berkshire Hathaway‘s Warren Buffett at $144 billion.

Shortly after the market opened Friday, Fortune‘s analysis of net worth had Huang ahead of Buffett, with the Nvidia CEO at $143.7 billion and the Oracle of Omaha at $142.1 billion.

Read more CNBC tech news

The company has also achieved its own notable milestones this year, as it prospers off the AI boom.

On Wednesday, the Santa Clara, California-based chipmaker became the first company to top a $4 trillion market capitalization, beating out both Microsoft and Apple. The chipmaker closed above that milestone Thursday as CNBC reported that the technology titan met with President Donald Trump.

Brooke Seawell, venture partner at New Enterprise Associates, sold about $24 million worth of Nvidia shares, according to an SEC filing. Seawell has been on the company’s board since 1997, according to the company.

Huang still holds more than 858 million shares of Nvidia, both directly and indirectly, in different partnerships and trusts.

WATCH: Nvidia hits $4 trillion in market cap milestone despite curbs on chip exports

Nvidia hits $4 trillion in market cap milestone despite curbs on chip exports

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