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?

Big Ideas in Geoscience, a DVD created by AGI to bring the Nine Big Ideas from the Earth Science Literacy Principles to life, has just won three prestigious awards: Digital Video (DV) Winner in Education, DV Winner in Nature/Wildlife and Videographer Award of Excellence.

In celebration of Earth Science Week 2012, the American Geosciences Institute (AGI) is sponsoring three national contests honoring this year's theme "Discovering Careers in the Earth Sciences." This year's competitions will feature a photography contest, a visual arts contest, and an essay contest. "

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.

The American Geosciences Institute (AGI) is now accepting advance orders for the Earth Science Week 2012 Toolkit. The Earth Science Week 2012 Toolkit contains educational materials for all ages that correspond to this year's event theme, "Discovering Careers in the Earth Sciences."

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 continuation of the Geoscience Academic Provenance research series conducted by Houlton (Geoscience Currents 45-48, and 57-58), Geoscience Currents 59 presents quantitative data collected from participants through a Likert-based survey. Participants were asked to rate their feelings toward geoscience on a scale from 1 to 7. The aggregated responses illuminated the changes over time in the students' attitudes toward pursuing geoscience.

The American Geosciences Institute has released Geoscience Currents 60, which examines female enrollments and degrees in the geosciences over time. In 2011, the Current concludes, female participation in U.S. geoscience degree programs remained generally steady. After decades of steady growth in the rate of female participation, there has been little change since 2005. Several interesting trends are also noted, including declines in doctorates awarded following economic downturns, and that women appear to have slightly higher degree completion rates than men at the Bachelor's and Master's levels.

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.