MacKenzie Scott, the ex-wife of Amazon founder and CEO Jeff Bezos, announced on Tuesday that she has donated roughly $1.7 billion to nonprofit groups dedicated to causes including racial justice, LGBT rights and public health.

Scott, who said she changed her surname following her divorce from the world’s richest man, wrote in a post shared on Medium that the donations are part of an effort to make good on her pledge from last year to donate the majority of her wealth “back to the society that helped generate it.” Scott’s net worth is currently $60.4 billion, making her the 13th-wealthiest person on the Bloomberg Billionaires Index.

“Like many, I watched the first half of 2020 with a mixture of heartbreak and horror,” Scott wrote. “Life will never stop finding fresh ways to expose inequities in our systems; or waking us up to the fact that a civilization this imbalanced is not only unjust, but also unstable. What fills me with hope is the thought of what will come if each of us reflects on what we can offer.”

Following up on the commitment I made last year to give away the majority of my wealth in my lifetime: https://t.co/Ocb8eU5UR1. (Note my Medium account is under my new last name — changed back to middle name I grew up with, after my grandfather Scott.)

— MacKenzie Bezos (@mackenziebezos) July 28, 2020

“Opportunities that flowed from the mere chance of skin color, sexual orientation, gender, or zip code may have yielded resources that can be powerful levers for change,” she added, noting that last fall she asked a team of nonprofit advisers to identify “organizations having major impact on a variety of causes.”

Her Medium post included a rundown of where the money has been allocated so far, with more than $586 million being dedicated to racial equity and $125 million focused on climate change. The groups that have received donations include the NAACP Legal Defense and Educational Fund, the George W. Bush Presidential Center, Advancement Project and Educate Girls.

The divorce between Scott and Bezos reportedly gave her 25 percent of Bezos’s Amazon holdings, which in turn made her one of the wealthiest women in the world.

In May 2019, Scott signed the Giving Pledge, a commitment to donate the majority of one’s wealth to charity that was launched by Microsoft co-founder Bill Gates and his wife, Melinda Gates, in 2010. More than 200 of the wealthiest people in the world have signed the pledge.

Bezos, who has not, earlier this year announced the launch of the Bezos Earth Fund, a new global initiative that will commit $10 billion to combating climate change.