( CNN ) -- The United Nations is holding a summit this week in Rio de Janeiro on global sustainable development , but , incredibly , family planning is not on the agenda . How can the summit ignore this elephant in the room ? When the world 's population hit 7 billion in October , experts warned that if nothing is done , the global population could grow by another 3.5 billion by 2050 . Still , many of the world 's women are without the resources to plan their families ' growth effectively -- a major factor in stemming the tide of global population expansion . Clearly , the world 's growing population and the significant challenges it poses must be central to any discussion of sustainable development at the U.N. Earth Summit , also called Rio+20 , taking place Wednesday , Thursday and Friday . Negotiators hammering out the terms for discussion in Rio failed to link the summit 's sustainable development goals to the concerns , needs and desires of women worldwide -- particularly to the role that family planning could play in easing the burdens posed by population growth . We know that when women have access to voluntary family planning services , supplies and information , society sees enormous gains in each of the three pillars of sustainable development -- human development , economic growth and environmental sustainability . Without it , families , communities and natural resources are extraordinarily burdened . Experts estimate that more than 215 million women around the world want to delay or space childbirth but are not using modern contraception . In fact , meeting this need would cost $ 3.6 billion per year , a small amount when you consider the enormous benefits . Providing modern contraception also has the potential to stem population growth and relieve human pressure on the environment and natural resources . We urge governments and global agencies at Rio to make this a priority . We are at a moment in history where we still have time to make a difference . It is essential that the global discussion in Rio not be blind to the potential solutions that access to voluntary family planning could offer to many of the world 's problems . Our goal is not to control the population : It is to empower women and families , giving them a say over when they will bring another child into this world . We know that when a woman can plan the size of her family , she is healthier , more likely to finish her education , join the labor force , become more economically productive and engage in politics , thus more effectively shaping the future of her family and her country . We also know that when governments invest simultaneously in voluntary family planning , public health and education , countries can benefit from the `` demographic dividend '' seen in the Asian Tiger countries . Frustratingly , instead of recognizing these links , Rio negotiators so far have sidelined them . Every second , every day , every year we fail to address demand for reproductive health and family planning services . Lives are lost and girls ' opportunities to thrive and contribute to their country 's development shrink . These are real people . We know that universal access to voluntary family planning services would prevent 150,000 maternal deaths and 25 million abortions every year . This is an issue all governments and negotiators should agree upon if we are serious about sustainable development . Today , opposition to voluntary family planning can only be attributed at best to outdated thinking , and at worst to a desire to undermine women 's rights . If the motto of the Rio conference is to be realized , that is , to build `` the future we want , '' leaders must step up and call for universal access to reproductive health and voluntary family planning for women everywhere who are denied this right . Consider the wider benefits to our planet . Providing women with the desired cost-effective , low-tech family planning services would not only dramatically reduce pressure on natural resources , increase supplies of food and water , decrease the risk of conflict over other scarce resources and improve ecological health , but scientists estimate such services would cut carbon emissions by up to one-quarter of what 's needed to slow climate change -- an outcome equal to ending deforestation around the world , or increasing 40-fold our reliance on wind power . My 15 colleagues and I on the Global Leaders Council for Reproductive Health , most of us former national leaders , call on our fellow leaders and negotiators not to ignore the elephant in the room . They must find the political will to make reproductive health fundamental to implementing sustainable development as a major outcome at Rio . At stake are the very goals the conference is meant to embrace . The opinions expressed in this commentary are solely those of Jenny Shipley .
Jenny Shipley : Rio summit on sustainable development must address population growth . Shipley : Family planning is essential to summit 's goal , yet it 's not on agenda . Shipley says 215 million women who want to plan families have no access to birth control . Shipley : Family planning enormously benefits women 's lives , the planet , economies .