One man's trash is quickly becoming society's new treasure. In the August issue of EARTH Magazine, we explore how materials that were once considered garbage are now being recognized for their true potential as valuable energy resources capable of solving multiple problems at once. If successful, these waste-to-energy" options could serve as a silver bullet - displacing fossil fuels, reducing greenhouse gas emissions, and decreasing the amount of trash that winds up in already teeming landfills. "

Resting in the Karakoram Range between northern Pakistan and western China, the Karakoram glaciers are stumping scientists. Unlike most mountain glaciers, the Karakoram glaciers, which account for 3 percent of the total ice-covered area in the world, excluding Greenland and Antarctica, are not shrinking. On the contrary, a team of French glaciologists has recently confirmed that these glaciers on average have remained stable or may have even grown slightly in recent years.

What are today's biggest unanswered questions in earth science? In the July issue of EARTH Magazine, experts from a variety of disciplines weigh in on what they consider to be the biggest unsolved mysteries across the geosciences and how they think we may solve them.

In the 1980s, acid rain was a big topic of conversation. Everyone knew about it. Today, just a couple of decades later, it's all but been forgotten. Why and how did this happen?

In the Late Quaternary, Australia was home to an array of megafauna. The half-ton Palorchestes azael, the rhinoceros-sized Diprotodon, and even the giant koala, Phascolarctos stirtoni, roamed Australia's interior. However, between 50,000 and 45,000 years ago, they all vanished. Although recent studies indicate human colonization as a potential cause of their extinction, the exact mechanism has never been resolved. Now, geologist Gifford Miller from the University of Colorado at Boulder and his colleagues believe they have uncovered the answer.

Global seismic hazard maps exist to help societies and decision-makers anticipate and prepare for earthquakes. These maps are supposed to depict the maximum level of ground shaking likely to be produced by an earthquake in a given area. In the past decade, however, ground motions and death tolls in areas struck by earthquakes have far exceeded these maps' projections. Thus, scientists are calling into question the standard methods used to estimate seismic risk, and accepted assumptions and calculations have come under fire.

In 2010, the world reached a milestone: The number of people living in urban areas reached 50 percent. This monumental shift from rural to urban living comes with consequences. Growing urban populations will have to learn to efficiently deal with increased demands for energy, transportation, sanitation, food and water while balancing the environmental impacts of such densely populated regions.

Volcanism is often implicated in periods of abrupt cooling. After the 1991 eruption of Mount Pinatubo in the Philippines, for instance, global temperatures dropped by half a degree Celsius due to airborne particulate matter blocking solar radiation. However, these effects don't normally last more than a few years. Yet, a recent study blames volcanism for a 500-year cold period referred to as the Little Ice Age.

The North Star, the Pole Star, the Guiding Star, Polaris: Its many names reflect the many centuries humans have gazed northward to it for guidance. However, recent studies have shown that the North Star is losing mass at a significant rate. Will Polaris, steadfast beacon for early sailors and adventurers alike, vanish from the night sky?

A new generation of lidar, or Light Detection and Ranging technology, is bringing the laser-based survey method down to Earth. The new technology involves mounting instruments atop cars, boats and even backpacks. These new mobile mapping systems will give geoscientists a whole new way to map and study the world.