Melinda Gates, the most powerful woman in philanthropy, has written a book about hope and female empowerment, at a time when women’s rights are coming under increasing threat in developed countries.

She and her husband, Bill Gates, the Microsoft founder, head a charitable foundation with the largest endowment in the world: US$50.7 billion.

This makes The Moment of Lift a major publishing event. The press kit comes with a printout of advance praise from the likes of Julie Bishop, Trevor Noah and Malala Yousafzai.

It also makes the author pretty handy at summarising her life for Australian interviewers: as she told Hack, she grew up in Dallas, Texas, and her dad was an engineer on the Apollo program. He’d take them to see the big rockets blasting off. She fell in love with computers in high school, did her MBA, and then took a job at Microsoft straight out of university. There she met Bill.

In 2000, the couple launched the Bill and Melinda Gates Foundation. Six years later Warren Buffett, then the world’s richest person, pledged US$37bn.

“I remember the moment when we learned about it and we both had tears,” Melinda told Hack.

“Bill and I went for a very long walk which is often where we work things through and just said oh my gosh what does this mean?”

By 2017, it meant the foundation was spending US$5 billion a year.

The enormously wealthy organisation, controlled entirely by trustees Bill, Melinda and Warren, ploughed money into reproductive health, agricultural research, family planning, and the control of malaria, tuberculosis, and STDs and other infectious disease.

The Moment of Lift is Melinda’s attempt to articulate what she’s learned from this frenzy of United States-led humanitarian aid and development.

Over the years, she’s had a insight: “It was like a slow-rising sun, gradually dawning on me – part of an awakening shared and accelerated by others”.

She describes this as her “huge missed idea”.

Humanity, she says, is at a defining moment where women are finally breaking free of centuries of oppression, and lifting up the whole of society: “As women gain rights, families flourish, and so do societies … Gender equity lifts everyone.”

“The engines are igniting; the earth is shaking; we are rising,” she writes.

“More than at any time in the past, we have the knowledge and energy and moral insight to crack the patterns of history. We need the help of every advocate now. Women and men. No one should be left out. Everyone should be brought in.

‘A wrestle with my faith’

In the book, Melinda names what she says is the greatest life-saving poverty-ending women-empowering innovation ever: birth control.

“If you look at what has allowed women in any economy to go into the workforce in droves it’s because they could plan and space the births of their children,” she told Hack.

“Women all over the world who don’t have access to contraceptives but know about them or had access in the past and now don’t they will tell you this is often a matter of life and death.

“They’ll say I can’t have another child, I cannot feed another child or even if I can feed the ones I have I can’t educate all of them.

“When you make sure that a woman has access to a contraceptive tool … she can then plan and space those births, and if she chooses she can go out and get a job and it literally lifts her out of poverty.

Having been raised a Catholic (the Vatican is opposed to birth control), it took Melinda a while to come to this impious realisation: “I was travelling more and more and more for the foundation. I was in and out of countries like Malawi and Senegal and Kenya.

“I would be there to talk to them about vaccines.

“They would bring the conversation around to ‘what about my contraceptive?’.

“As I heard those cries among women just yelling at me I thought gosh why aren’t we doing something about this? It took me a few years honestly to wrestle with my faith.”

Teaching equality to Bill Gates

While learning about the structural causes of mass poverty, Melinda was also managing the challenges that came with being married to one of the richest men in the world.

“I mean he was running Microsoft,” she told Hack.

“He was in the position of power so he wasn’t used to sharing power, or he wasn’t used to even understanding that when he walks in the room or sits down at a table everybody assumes he’s the smartest person in the room.”

If he spoke over her at a dinner party she’d pull him up on the drive home: “He had to learn to make room for me, which he absolutely does now.”

This may seem a long way from access to birth control, but Melinda says she tells this story to connect equality within a marriage with the broader issue of gender relations in society.

“Until we have these conversations in our home we don’t then fully live them out in our communities and our workplaces,” she says.

She says she and Bill and have removed hierarchy in their relationship, except for flexible and alternating hierarchies based on talent, interest or experience: “It is a little bit tricky but it works for us, and I think it can work for other people.”

Again, she connects this with the broader issue of women being expected to perform unpaid labour in the home – something that adds up to years of missed opportunity.

“In the US over the course of a lifetime it’s actually seven years of unpaid labour in the home,” she told Hack.

“I don’t know about you but with seven years I could get a couple of degrees, I’d go back to school – so we need to rethink those assumptions.”

Bill and Melinda go to the White House

In March 2017, Bill and Melinda met Donald Trump in the White House after the President had announced plans to systematically roll back healthcare for women – including limiting access to birth control and abortion and bolstering abstinence-only sex education.

“I thought it was important for me to speak out,” Melinda said.

The conversation, she says, didn’t go well: the President simply didn’t seem to be taking on any of what she was saying.

“I don’t think I got very far – I wish I’d gotten farther but I just didn’t.

The Moment of Lift has been published during a dark and uncertain period for women’s rights in the United States, and potentially in other developed countries.

Politicians with hyper-masculine identities and ideologies are on the rise everywhere – often in response to the forces of women’s liberation that Melinda champions.

Her message for young Australians: “You can change somebody’s life – one small act has ripples in the pond that sometimes you don’t even know are there.

“Go out and learn about the needs of somebody else in your community.

“If you’re lucky enough to travel outside of Australia, learn about the needs of someone else in the world because if you help lift up someone else and particularly if you help lift up a girl or woman she lifts up everyone else.”