Can you be too clean to be healthy? Doctors are now saying the answer is yes -- and that some exposure to dirt and pets early in infancy can help prevent allergies, asthma and autoimmune diseases.

GERMANY HAS BEEN LAUDED as the leader in distributed, clean energy, its renewable energy strategy touted as one of the most innovative and successful worldwide. The claim certainly has validity—Germany has increased the share of its total electricity production from renewables from 6% to 30% over the past decade; it has the highest per capita installed solar power capacity in the world; and its feed-in tariff (FIT) policy establishes long-term, fixed fee contracts for renewable energy producers, encouraging households, cooperatives, and communities alike to produce clean distributed energy.

However, when examining the country’s total energy portfolio, the facts belie Germany’s reputation as “the world’s first major renewable energy economy.” In glaring contrast to its image as a leader in sustainability, Germany is a heavy user of coal and the largest importer of Russian natural gas (over 40 billion cubic meters in 2013).

Elon Musk is changing the world. The visionary South African-born entrepreneur has radically changed the transportation sector through his groundbreaking companies Tesla and SpaceEx. His solar leasing company, SolarCity, is delivering affordable solar solutions to homeowners across the country. Now, Musk is poised to deliver a sea change in the battery industry, opening the door to massive advancements in clean technology.

Every five years, China's Central Government issues a new Five-Year Plan (FYP), a detailed outline of the country’s economic goals for the upcoming ve-year period. The current FYP—the 12th—covers the period from 2011to 2015.

The 12th FYP, which has been hailed as the “greenest” ever, calls for an increase in non-fossil fuel use to satisfy 11.4 percent of electricity demand. It also singles out seven “Strategic Emerging Industries” for special support, three of which are based on emerging energy technologies: new energy, energy conservation and environmental protection, and clean-energy vehicles. The Chinese government plans to invest hundreds of billions of dollars in developing these industries over the period covered by the Plan.