| Today, just one in three scientific researchers is a woman. However, addressing the complex global challenges we face - such as climate change, biodiversity loss, extreme poverty, and the need for ethical approaches to artificial intelligence – requires gender equality in science. As science thrives on multiple voices and skills, every girl and woman with the potential to make contributions to science should be supported and encouraged in realizing her aspirations. That is why on this year’s International Day of Women and Girls in Science (11 February), UNESCO is emphasizing the critical need to accelerate action to close the gender gap in science. Women Scientists Across Borders and Disciplines Over the past decade, the average ratio of female researchers (1 in 3) has merely not varied. As we climb the professional ladder, women’s representation drops, with, for instance, only 12% of women holding members’ positions in national academies of science. The number of women scientists varies among countries, suggesting that a country’s wealth does not necessarily correlate with success in achieving gender parity in science. However, not all countries possess reliable data, which limits reporting on the extent of gender gap in science. The gender gap also differs across scientific disciplines. Fields like physics tend to attract more men than women, whereas life sciences and health disciplines often show a more balanced gender distribution. Globally, women comprised only 28% of engineering graduates and 40% of computer science graduates in 2018.  Understanding Gender Inequality in Science Contrary to misconceptions, the observed differences in women’s participation in science in various countries and scientific disciplines indicate that the gender gap in science is not a result of innate differences between men and women or a country's economic status. Instead, they reflect a complex interplay of societal factors and systemic barriers that hinder girls and women's access to scientific careers. These barriers include social, cultural and gender norms that guide expectations and roles, low levels of self-efficacy, a lack of visible role models, underrepresentation in leadership roles, poorly qualified teachers and unsupportive learning environments, and inadequate professional structures and work cultures.  UNESCO’s Call to Action: Closing the Gender Gap in Science In response to these challenges, UNESCO published the Call to Action “Closing the Gender Gap in Science” last Friday. This initiative aims to ensure that girls are never discouraged from pursuing their aspirations to become scientists and to convey to them that such goals are indeed attainable. The Call to Action also suggests actions to dismantle the barriers that hinder women from realizing their full potential in science, in order to break the glass ceiling that prevents them from attaining scientific excellence and leadership positions in scientific systems across the world. The actions recommended in the document cover a wide spectrum, ranging from innovative learning strategies and appropriate career counselling to more visibility of role models, from enhancing inclusive and fair workplace environments to promoting women in leadership positions. On Friday, 9 February, UNESCO organized an event at its Headquarters in Paris to celebrate this International Day and to launch the Call to Action mentioned above. The event mobilized Member States, accomplished and emerging scientists, stakeholders from the public and private sectors, UNESCO scientific networks and Chairs, as well as students. The recordings and reports of this event will be soon available on the following website: International Day of Women and Girls in Science | UNESCO. | 
