The original version of this article, by Michael D. Lemonick, appeared on Climate Central.

 In May, a team of British scientists abruptly canceled an experiment they had been planning for nearly two years. The Stratospheric Particle Experiment for Climate Engineering, or SPICE, was intended to test ways of injecting tiny particles of sulfur dioxide into the upper atmosphere, with the eventual goal of filtering out sunlight to cool the Earth in the face of global warming. The main reason given for the cancellation was a potential patent dispute over some of the technology involved.

Twenty-five years have passed since the Brundtland Commission first brought sustainable development to international prominence. Today, the United Nations appears on track to replace the soon-to-expire Millennium Development Goals with “Sustainable Development Goals,” marking the extent to which the international community has embraced the concept. And yet, in spite of its prominence, a specific and measureable definition of sustainability remains lacking.

It’s not often that a change in accounting rules could reduce the probability of war. But that’s exactly what happened at the U.S. Securities and Exchange Commission (SEC) last month.

In 1979, Egyptian President Anwar Sadat famously said that “the only matter that could take Egypt to war again is water.” Sadat’s message was clear: the Nile is a matter of national security for Egypt.

Indeed, Egypt relies on the Nile for 95 percent of its water. But it is not the only state with an interest in the world’s longest river. There are 11 states in the Nile River basin, which stretches from Africa’s Great Lakes region – Tanzania, Uganda, Kenya, Rwanda, Burundi, and the Democratic Republic of the Congo – to the Ethiopian and Eritrean highlands through South Sudan, Sudan, and Egypt to the Mediterranean Sea.

“Population-health-environment [PHE] connections have really been a focus of ours here at the Wilson Center for the last 15 years,” said outgoing ECSP Director Geoff Dabelko in an interview at the Wilson Center. The goal of ECSP’s project – HELPS (health, environment, livelihoods, population, and security) – is “really trying to understand these issues together.”

Over the next two decades, as many as three billion people will join the middle class, even as billions more live without electricity, modern cooking fuel, and safe and reliable access to food and water. Resources are becoming more scarce and more difficult to extract, and combined with environmental factors ranging from climate change to soil erosion, those changes will make meeting middle class demand all the more difficult while leaving the world’s poorest more vulnerable to price shocks and resource shortages. In a recent report, the McKinsey Global Institute concludes that nothing less than a “step change” in how resources are managed will be required if individuals, businesses, and governments are to overcome these trends and pave the way for a more sustainable and equitable future.

Specifically attributing a particular weather event to climate change has been difficult – as one famous analogy goes, it’s like determining which of Mark McGwire’s home runs were because of steroids and which weren’t. But climate attribution science is slowly becoming more accurate and accepted. In “Explaining Extreme Events of 2011 From a Climate Perspective,” a new study appearing in July’s Bulletin of the American Meteorological Society, editors Thomas C. Peterson, Peter A. Stott, and Stephanie Herring provide a review of six extreme weather events from last year and offer “some illustrations of a range of possible methodological approaches” to the process of attribution. Among their conclusions, the editors note that, due to climate change, the extreme heat and drought that suffocated Texas in 2011 was 20 times more likely to occur than 40 years earlier. However, the devastating floods that swept across Thailand last year are blamed on a number of other non-climatic factors.

The original version of this article, by Christina Larson, appeared on Yale Environment 360.

Bouncing along bad roads in a jeep through central Mongolia, with bright blue skies and high clouds overhead, we drive for miles through a treeless landscape, passing only dry grasslands dotted with cattle and white yurts. But as we head north – myself, two U.S. scientists, and one Mongolian forestry expert – we begin to notice Siberian pine and larch growing on the northern slopes of rolling hills, but not the southern slopes, and at some elevations, but not others. In water-scarce Mongolia, as my travel companion Neil Pederson of Columbia University’s Lamont-Doherty Earth Observatory explained, the precarious growth of trees is limited by temperature and moisture availability; small variations – northern slopes are slightly cooler and wetter – can make all the difference.