Some of the world's wealthiest business titans just promised to use their fortunes to do good.

An additional 14 individuals and couples from seven different countries joined the Giving Pledge, an initiative launched by Warren Buffett and the Bill & Melinda Gates Foundation in 2010. The pledge's goal is to encourage billionaires and their families to dedicate the majority of their wealth—at least half—to philanthropic causes, either during their lifetimes or after their deaths.

The new signatories announced Tuesday include Australian gaming tycoon Leonard H. Ainsworth, easyJet airline founder Stelios Haji-Ioannou, and investor Robert F. Smith. Past signers include Facebook CEO Mark Zuckerberg, Chobani yogurt founder Hamdi Ulukaya, and former New York City Mayor Michael Bloomberg.

Tuesday's additions, whose causes range from climate change and environmental protection to poverty alleviation and medical research, show the growing international scope of the initiative. There are now 168 signatories from 21 countries.

"Philanthropy is different around the world, but almost every culture has a long-standing tradition of giving back," Melinda Gates, co-chair of the Bill & Melinda Gates Foundation, said in a statement. "Bill and Warren and I are excited to welcome the new, very international group of philanthropists joining the Giving Pledge, and we look forward to learning from their diverse experiences."

"Philanthropy is different around the world, but almost every culture has a long-standing tradition of giving back."

In 2010, Bill Gates told Fortune that giving away half of one's fortune was a "low bar." The Giving Pledge, however, is a moral pledge, not a legal one. There's no enforcement mechanism involved in signing, which means that signatories technically aren't obligated to give anything away. And because some billionaires may choose the option to leave sizable donations in their wills, the overall effects of the pledge might be considered long-term at best.

To give the pledge's impressive roster of billionaires the benefit of the doubt, they likely do have the planet's best interests at heart, in one way or another. Millions of dollars from people like Zuckerberg and his wife Priscilla Chan, Microsoft cofounder Paul Allen, and Virgin Group founder Richard Branson have certainly gone to good causes over the years, with or without the pledge. But signing, of course, comes with positive press and accolades. And there's definitely PR incentive to add your name to a list of the world's most elite do-gooders.

"It's like joining a club, that's all it is," Leonard Tow, the CEO of New Century Holdings who joined the pledge five years ago, told Bloomberg in 2015. "There wasn't any thinking about it."

The Giving Pledge also hints at the perils of "philanthrocapitalism." Simply throwing money at big, systemic problems without addressing the causes of inequality affects just how impactful large donations can be. This kind of practice reveals how a lack of accountability and a lack of questioning of the economic and societal factors that led to their extreme wealth is frequently at odds with their causes.

A slightly more optimistic view of the Giving Pledge, perhaps, is that these billionaires are still adding to the larger global philanthropy conversation. Those with the power—and pockets—to make a difference can and should do so. They're setting an example for other wealthy business leaders, who have a staggering amount of influence on policy and social change because of their dollars.

When business leaders speak up and economic interests are at stake, policymakers listen.

Look, for example, at the companies that signed the American Business Act on Climate Pledge ahead of the Paris Climate Agreement in 2015, or, more recently, the U.S. tech giants urging President Trump not to back out of said agreement. And just this week, more than a dozen tech leaders from companies like Apple, Facebook, and Google condemned the Texas bill that, if passed, would prevent trans people from using bathrooms that match their gender identities. This mirrors what happened in North Carolina and Georgia last year, with dozens of companies condemning similar, infamous "bathroom bills" in those states. People like Salesforce CEO Marc Benioff and PayPal Dan Schulman also publicly warned of the economic damage their business decisions could do in response to these bills.

Regardless of outcome, when business leaders speak up and economic interests are at stake, policymakers listen. Businesses with a social conscience have quickly become the norm, not an exception, and research shows that's what most consumers want—when it's genuine and impactful.

To a certain extent, the Giving Pledge can also offer a model to all people regardless of income level. It sends the message that donating what you're able to, and using any privilege you've been afforded to help vulnerable and marginalized communities, can spur real change.

Effective or not, the Giving Pledge adds momentum to a discussion we need to be having about philanthropy, tangible action, and the relationship between the two.

Here's the full list of the new billionaire signatories announced Tuesday. You can learn more about them, and read their "Giving Pledge letters," here.