He said it was relevant as women and girls did some 12 billion hours of unpaid care work every day that simply did not figure in economic decision-making.

The secretary general in a statement issued in Accra and copied to the Ghana News Agency (GNA) in commemoration of the Women's Day celebration, said, it was a barrier to solving many of the challenges and threats countries faced.

It said gender inequality was the overwhelming injustice of age and the biggest human rights challenge faced.

But gender equality offers solutions to some of the most intractable problems of our age.

It said women in the world were worse off than men – simply because of their gender.

The reality for women from minorities, older women, those with disabilities and women migrants and refugees was even worse. 

"We have seen enormous progress on women's rights over recent decades, from the abolition of discriminatory laws to increased numbers of girls in school, we now face a powerful pushback.

"Legal protections against rape and domestic abuse are being diluted in some countries, while policies that penalize women, from austerity to coercive reproduction, are being introduced in others. Women sexual and reproductive rights are under threat from all sides.

All this is because gender equality is fundamentally a question of power. Centuries of discrimination and deep-rooted patriarchy have created a yawning gender power gap in our economies, our political systems and our corporations. The evidence is everywhere," it stated. 

Women are still excluded from the top table, from governments to corporate boards to prestigious award ceremonies.

Women in leaders and public figures face harassment, threats and abuse online and off. The gender pay gap is just a symptom of the gender power gap, it stated.

Even the supposedly neutral data that informs decision-making from urban planning to drug testing is often based on a "default male"; men are seen as standard, while women are an exception.

Women and girls also contend with centuries of misogyny and the erasure of their achievements.

They are ridiculed as hysterical or hormonal; they are routinely judged on their looks; they are subjected to endless myths and taboos about their natural bodily functions; they are confronted by everyday sexism, mansplaining and victim-blaming.

The latest research by the World Economic Forum says it would take 257 years to close the inequality gap.

It said the lack of gender balance in the universities, start-ups and Silicon Valleys of the world is deeply worrying.

These tech hubs are shaping the societies and economies of the future; we cannot allow them to entrench and exacerbate male dominance.

There is even a gender gap in our response to the climate crisis. Initiatives to reduce and recycle are overwhelmingly marketed at women, while men are more likely to put their faith in untested technological fixes. And women economists and parliamentarians are more likely than men to support pro-environmental policies, it said.

"Finally, political representation is the clearest evidence of the gender power gap. Women are outnumbered by an average of 3 to 1 in parliaments around the world, but their presence is strongly correlated with innovation and investment in health and education," it stated.

It is no coincidence that the governments that are re-defining economic success to include wellbeing and sustainability are led by women. 

"This is why one of my first priorities at the United Nations is to bring more women into our leadership. We have now achieved gender parity at the senior level, two years ahead of schedule, and we have a roadmap for parity at all levels in the years to come.

Our world is in trouble, and gender equality is an essential part of the answer. Man-made problems have human-led solutions.

"Gender equality is a means of re-defining and transforming power that will yield benefits for all. 

The 21st century must be the century of women's equality in peace negotiations and trade talks; in board rooms and classrooms; at the G20 and the United Nations.

It is time to stop trying to change women, and to start changing the systems that prevent them from achieving their potential, it said.