Anonymous gifts are common. But a climate group says a $10 million gift it got is an all-out mystery

abcnews.go.com:

A climate philanthropy organization, Giving Green, received a $10 million anonymous donation in April and thinks that the same donor may have given even more

On a Friday morning in April, Dan Stein, the founder of Giving Green, a climate philanthropy organization, found some big news in a surprising email. An anonymous donor had given his fund $10 million.

“I didn’t quite process the number of zeroes,” Stein said, adding he was “tickled, awestruck, surprised” by the gift.

Giving Green collects donations and disperses them to a handful of nonprofits that it believes have the potential to make a significant difference in preventing climate change and reducing the emissions of greenhouse gases. The $10 million donation is by far the largest single gift the nonprofit has ever received and it essentially fell out of the sky without warning.

The mystery gift went to Giving Green's fund, which is housed at Giving What We Can, an organization inspired by effective altruism that asks people from all over the world to pledge to give away a percentage of their income or their wealth each year. The donor is anonymous with the gift coming from a donor-advised fund at Fidelity Charitable.

“At first, they also were nervous that it was a mistake, and they went back to Fidelity to verify it before they told us,” Stein said of Giving What We Can.

Looking back at their records and speaking with organizations they recommend, Stein and his team think the same donor may actually have given as much as $17 million more directly to those organizations in the last two years. Because the gifts are anonymous, it's impossible to confirm, but Stein says the timing of the gifts, which came in two clusters, suggests they could have come from the