Near the corner of Broadwick and Lexington in London’s Soho neighborhood, a single spot on the ground has influenced more than 150 years of urban development. It’s the location of a water pump that in 1854 physician John Snow pinpointed as the source of contamination leading to a widespread outbreak of cholera in the neighborhood that killed more than 600 people.

Times are good for Fey Wei Dong. A genial, middle-aged businessman based in Hangzhou, Fey says he is raking in the equivalent of $225,000 a year from trading in the humblest of commodities: sand.

One of the findings of the Worldwatch Institute’s Family Planning and Environmental Sustainability Assessment (FPESA) suggests it’s not accurate to claim that climate change is at the root of growing water scarcity around the world. Based on the best recent scientific evidence we could find, another major global trend – the ongoing growth of human population – has a greater impact on water availability than climate change does.

In the late 1990s, world leaders came together to create the Millennium Development Goals – time-bound, quantified targets for addressing extreme poverty and human health and well-being. Notable among them was to “halve, by 2015, the proportion of the population without sustainable access to water and sanitation.”

At USAID we recognize the threat poor sanitation combined with rapid urbanization presents to human health, dignity, and prosperity. This is why we have made urban sanitation a global priority for the Agency. During a recent visit to India, I was able to see some of the work being done to bring sanitation services to urban areas, and had the good fortune to meet some inspiring women who are advancing these efforts in their communities.

Last month, the world came to Copenhagen to focus on how to achieve the Sustainable Development Goals (SDGs) for girls and women. The Women Deliver Conference, the largest gathering on girls’ and women’s health and rights in the last decade, was a huge success. Convening over 5,700 likeminded people from 169 countries was important to reenergize the movement and inspire action. Preaching to the converted is sometimes important. But now it’s time to focus on those who are not yet converted.

Climate change is expected to affect rural to urban migration and Omar O. Chisari and Sebastian Miller, in a recently released working paper by the Inter-American Development Bank, analyze the various policy options available in two cases: domestic migration to São Paulo, and international migration from Bolivia and Paraguay to Argentina. Migration into cities will impact climate change mitigation strategies.

Anyone visiting Singapore, as I did recently, quickly realizes it is exceptional. A tiny, rich, stable city-state of nearly 6 million people perched uneasily in a region of sprawling mega-countries full of poverty and instability, it also a thriving free market trading and financial center that is meticulously planned and where 80 percent of people live in public housing.