Who pays the price of loss of biodiversity, climate change and desertification? According to the 'Rio Conventions' - the United Nations (UN) Convention on Biodiversity, the UN Framework Convention on Climate Change (UNFCCC), and the UN Convention to Combat Desertification (UNCCD) - it is rural populations in poor countries. In fact, gender-related patterns of vulnerability mean that the impact of climate change is different on women compared to men. Through an examination of each convention, this paper asserts that it is essential for a gender perspective to be applied to these conventions for two key reasons. Firstly, the successful implementation of each convention requires a solid understanding of the different ways in which women and men use and respond to environmental resources (such as water and land), as well as an understanding of the gender-specific impacts of environmental degradation. For example the majority of women farmers do not have secure land rights and their productive assets are generally of a lesser value than men's. Both of these factors limit women's potential to adapt their activities in the face of shocks such as sudden shortages in food supplies, drops in income, crop failure and natural disasters. Secondly the successful implementation of each convention will depend on the participation of affected populations, both women and men - equal participation of women cannot be taken for granted. The paper reviews gender mainstreaming in international agreements on sustainable development before ending with reflections on the policy challenges in convention implementation. Enhancing the gender-responsiveness of the Rio conventions depends ultimately on political will - both in governments and institutions.