UN Secretary-General Ban Ki- moon on Friday encouraged women to take leadership roles in disaster risk reduction (DRR), calling them "the invisible force of resilience." In his message commemorating the International Day of Disaster Reduction (IDDR), which falls on October 13, Ban emphasized that women and girls are "powerful agents of change" and that "across the world, women and girls are using their roles within families and communities to strengthen risk reduction." The theme of this year's celebration, "Women and Girls: the [ in]Visible Force of Resilience," seeks to highlight the need for women and girls to be at the forefront of reducing risk and managing the world's response to natural hazards, said the UN chief. He stressed that "communities can benefit from encouraging women to take leadership roles in disaster risk reduction." According to Ban, extreme weather and disasters affect on average "more than 200 people annually" and people need to understand their personal and environmental risks and find ways to reduce them, like the women in Bangladesh highlighted by the secretary-general. The Bangladeshis women organized themselves to prepare for and respond to floods by teaching other women how to build portable clay ovens and elevate houses. This is an example among others pointed out by the UN chief of women at the forefront of "reducing risk" and helping their community respond to natural disasters. Women "will only become more valuable as climate change intensifies and as the world struggles to cope with extreme weather and disasters," he added. On 22 December, 1989, the UN General Assembly designated the second Wednesday of October International Day for Natural Disaster Reduction. The International Day was to be observed annually during the International Decade for Natural Disaster Reduction, 1990-1999. By a resolution of December 21, 2009, the General Assembly decided to designate October 13 as the date to commemorate the Day and to change the Day's name to International Day for Disaster Reduction. The objective of the observance is to raise awareness of how people are taking action to reduce their risk to disasters.