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.

The original version of this op-ed, by António Guterres, appeared in The New York Times.

For many people, Timbuktu has long represented the essence of remoteness: a mythical, faraway place located on the boundaries of our collective consciousness. But like many of the myths associated with colonialism, the reality is very different.

The number of urban slum dwellers worldwide is staggering. According to UN-Habitat, 827.6 million people live in slums around the world. Despite meeting a Millennium Development Goal to significantly improve the lives of at least 100 million slum dwellers by 2020, the total number of people living in these areas still increased by 55 million between 2000 and 2010. By 2020, the world slum population is projected to reach 889 million. With the majority of people now living in cities, urban priorities are synonymous with human security and environmental sustainability and must be accounted for in the global development agenda.

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.

Climate change “has been thought of in many quarters as something that affects folks ‘over there,’ and not as much domestically, and I think that’s a mistake,” said ECSP’s Geoff Dabelko in a recent podcast with the Zurich-based International Relations and Security Network. “I think folks are coming to a realization that there are very high economic, political, and ultimately security stakes for the United States.”