His observations of the recent changes in climate match forecasts for the region: In East Africa, climate change is expected to reduce the productivity of maize – Malawi’s main subsistence crop – by more than 20 percent by 2030, according to a recent analysis by Oxfam International I looked out the window at dusty fields and tried to imagine what Malawi might look like in 2030. For one thing, it will be more crowded. A lot more crowded. According to UN population projections , by 2030, Malawi’s population will have grown from about 15 million today to somewhere between 26.9 and 28.4 million. With climate change dampening agricultural productivity and population growth increasing food demand, how will Malawians – many of whom don’t have enough to eat– have enough to eat in the future?It gets quiet in the taxi as the driver and I both ponder this question. Malawi is not alone in being a climate-vulnerable country with a rapidly growing population dependent on rain-fed agriculture. Population Action International’s Mapping Population and Climate Change tool shows us that many “hotspot” countries – scattered across Latin America, Africa, and Asia – face the triple challenge of low climate change resilience, projected decline in agricultural productivity, and rapid population growth.Agricultural trade, government safety net programs, and foreign assistance will no doubt continue to play an important role in the quest for food security in Malawi and other “hotspot” countries in the future. And climate change adaptation projects will, hopefully, reshape agricultural practices and technologies in ways that can boost yields and enable crops to better withstand temperature and precipitation fluctuations.These interventions will be critical in addressing the supply side of future food security challenges. But what about growing demand?Juxtaposing population growth with food production does, of course, bring us back to Thomas Robert Malthus’ original (and by now somewhat infamous) dire warning: that population growth would eventually outrun food supply. But seeing the scale of the challenges in Malawi firsthand, I must admit that my inner Malthus sat up and took notice.It is true that technological advances have enabled astounding growth in agricultural yields that have enabled us to feed the world in ways the doom-filled Malthus could never have imagined in the early 19th century. But it is also true that the agricultural productivity gains that helped us keep pace with population growth for so long are beginning to slow: According to the U.S. Department of Agriculture , aggregate agricultural yields averaged 2.0 percent growth annually between 1970 and 1990, but that growth in yields declined to 1.1 percent between 1990 and 2007, and is projected to decline to less than 1.0 percent in the years to come.This comes at a time when the Food and Agriculture Organization reports that food production will need to increase by 70 percent by 2050 in order to adequately feed a larger, wealthier, and more urbanized population.To dismiss any talk of population growth as outmoded Malthusian hand-wringing misses an opportunity to embrace interventions that can contribute significantly to prospects for future food security – namely, empowering women with information and services that enable them to determine the timing and spacing of their children.In Malawi and many of the “hotspot” countries around the world, high proportions of women remain disempowered in this regard. Meaningful access to family planning and reproductive health services results in smaller, healthier families that will be better equipped to cope with the food security challenges that are headed their way.Not only does a smaller family mean that limited household resources go further, but access to family planning and reproductive health services is connected to other important education and economic outcomes.A new Population Reference Bureau policy brief , for example, highlights how improving women’s reproductive health will not only lead to declining fertility and slower population growth in sub-Saharan Africa, but can also contribute to balancing a woman’s many roles (agricultural producer, worker, mother, caregiver, etc.) in ways that support greater food security for her family. And research by the International Food Policy Research Institute shows that in developing countries, women’s education and per capita food availability are the most important underlying determinants of child malnutrition – with women’s education having the strongest beneficial impact. Access to family planning paves the way for these outcomes – and by slowing population growth, can help to slow the growth in food demand.The scale of potential benefits of meeting women’s family planning needs is significant when thinking about future food demand, both globally and especially in food insecure, climate-vulnerable countries. As we have seen in Malawi, there is a range of possible future population sizes and that range grows even wider when the projections are extended to 2050: According to the UN, Malawi’s 15 million today will grow to somewhere between 45 million and 55 million by 2050 That span of 10 million people embodies assumptions about declining fertility in Malawi. To reach 55 million, the average number of children per woman would need to drop from 5.7 today to 4.5 by 2050. If fertility drops further, to 3.5 children per woman, Malawi’s population would grow to (only) 45 million. Where Malawi ends up in that 10-million-person population spread will have deep implications for per capita food availability, not to mention other important development outcomes.Fertility declines of this kind do not require coercion or “population control.” As we have seen time and again , when women are empowered with information and services that enable them to determine the timing and spacing of their children, smaller, healthier families are the inevitable result.Meeting women’s needs for reproductive health and family planning services is not – and never should be – about reducing population size. Universal access to reproductive health is recognized as a basic human right and central development goal (embodied in Millennium Development Goal 5 ) because of its vital connections to women’s and children’s health, education and employment opportunities, and poverty alleviation. And yet, too many women remain without the ability to effectively plan their families. In Malawi, one in four married women would like to delay their next birth or end child-bearing all together but aren’t using contraception; globally, 215 million have this unmet need As global efforts ramp up to address interlinked challenges of food security and climate change adaptation, assessing the role of population growth is more important than ever. And in designing strategies to address these challenges – strategies like the U.S. Government’s Feed the Future Initiative and UN-supported National Adaptation Plans – we should not pass over opportunities to incorporate interventions to close the remaining gap in universal access to family planning, especially in places like Malawi and other “hotspot” countries (such as Haiti, Nigeria, and Nepal), where women’s unmet family planning needs are high and population growth is rapid.