The titans of the tech industry like to think of themselves as solvers of big world problems, and, lately, they’re tripping over themselves to show that they are working to solve a problem for which they, too, are culpable: climate change.

Apple on Tuesday became the latest tech giant to promise to do more to reduce the emissions of planet-warming greenhouse gases, announcing in a statement that, by 2030, "every Apple device sold will have net-zero climate impact."

Apple said it aimed to reduce emissions by 75 percent in its manufacturing chain, including by recycling more of the components that go into each device and nudging its suppliers to use renewable energy. As for the remaining 25 percent of emissions, the company said it planned to balance them by funding reforestation projects. The company also said it planned to improve energy efficiency in its operations.

Forests absorb carbon dioxide, and reforestation has become a popular way for companies to offset the greenhouse gas emissions that they produce, including from factories.

Climate advocates describe these offset efforts as inadequate because they allow emissions to grow at a time when the scientific consensus demands that emissions be cut in half by 2030 in order to avoid the worst effects of climate change — and be reduced to zero by 2050.

Separately on Tuesday, Microsoft announced that it would require its suppliers to report their emissions, as a first step toward making reductions.

Like other corporate pledges, both are entirely voluntary.

"It feels like there’s a virtuous follow-the-leader thing happening here," said Simon Nicholson, co-director for the Institute for Carbon Removal Law and Policy at American University.

He noted the limitations of the pledge, though. "What Apple has signaled here is the beginning of a strategy on the carbon-removal side," Dr. Nicholson said. "Holding carbon in forests for a year or two isn’t going to cut it. It needs to be held in forests for the long term, which means centuries."

Big Tech’s role in global warming varies from company to company. Amazon, Facebook and Google all use enormous amounts of energy and water for their data centers. Amazon relies on gas-guzzling trucks and packages that themselves have a huge environmental footprint; even recycling uses a lot of energy. And makers of devices — like Amazon, Apple, Google and Microsoft — produce greenhouse gas emissions through their supply chains, which involve contractors that do the actual manufacturing in different parts of the world.

The pressure on companies to do something about their climate footprint comes both from within the ranks of their employees and from advocacy groups on the outside.

Not only are they under scrutiny for the emissions they produce. Internet companies, like Facebook, have been criticized for allowing the spread of disinformation about climate science. Greenpeace took aim at Google, Microsoft and Amazon for using their artificial intelligence and cloud computing services to help oil producers find and extract oil and gas deposits, which Greenpeace said is "significantly undermining" the tech companies’ other climate commitments.

One by one, the giants of Silicon Valley have been compelled to address their own role in the climate crisis.

Google said in May it would no longer build customized artificial intelligence technology or machine learning algorithms for the oil and gas sector. It has also pledged to include recycled material in its devices, including its popular Chromebook computers, by 2022.

Amazon announced last September its bid to be carbon-neutral by 2040, while its chief executive, Jeff Bezos, committed $10 billion to fund climate science and advocacy.

Amazon’s move came after sustained calls from its own employees to reduce emissions to zero by 2030, a full 10 years earlier than the company’s current target. Its employees also pressed Mr. Bezos to stop offering custom cloud-computing services to the oil and gas industry and to suspend campaign donations to politicians who deny climate science.

Amazon continues to do business with fossil fuel companies, but Mr. Bezos said the company would take a "hard look" at its political donations. Amazon said it would reduce its climate change impact by, among other things, buying a fleet of 100,000 electric delivery trucks. But, like Apple, Amazon’s pledge to be net-zero by 2040 relies on reforestation projects to offset its continuing emissions. The company has also said it plans to improve energy efficiency in its operations.

Microsoft this year said it would draw down more emissions than it adds and also somehow remove all the emissions the company has ever produced. It promised to invest $1 billion in what it called climate innovations, but it left untouched its partnerships with oil and gas companies.

Facebook announced that it would use 100 percent renewable energy in its facilities and reduce water use in its data centers, though it has said little about what it will do to stop the spread of climate disinformation on its platform.

Apple’s net-zero pledge is notable in that it seeks to address the main source of its greenhouse gas emissions: from the manufacturing of its phones, tablets and computers by its contractor companies.

Apple’s statement on Tuesday underscored the need for businesses like it to pivot away from fossil fuels for the sake of its own bottom line. "We have a generational opportunity," said Lisa Jackson, a company vice president responsible for environmental issue, "to help build a greener and more just economy, one where we develop whole new industries in the pursuit of giving the next generation a planet worth calling home."

Elizabeth Jardim, who works on corporate issues at Greenpeace USA, cautiously welcomed the pledge as a step up from the company’s previous commitments, noting in an email that "as with all ‘carbon neutral’ or ‘carbon negative’ goals, it is critical to see detailed plans for how the company will pursue deep decarbonization rather than a reliance on offsetting or weak nature-based carbon removal initiatives."

Ms. Jardim also urged large, profitable companies to throw their weight behind policies like the Green New Deal.

On Twitter, Edward Maibach, of the George Mason University Center for Climate Change Communication, called the Apple pledge "a big step in the right direction, if they make good on it. Next, they should lobby governments worldwide to increase their commitments to the Paris Climate Agreement."