Here are some noteworthy science and environmental links folks are Digging today:

Daily Mail: "Forests in the sky could be built to clean air of pollution"

— Architects have designed a climate-change-fighting skyscraper that holds up to 400 trees hundreds of feet in the air, absorbing carbon dioxide emissions from nearby factories. The CO2 Scraper uses a wind-powered pump system to supply the trees with water and nutrients, and would reportedly improve local air quality and temperatures on top of reducing greenhouse gas emissions.

• Green Car Reports: "Islamic Scholar Suggests Using Ethanol-Powered Vehicles May Be a Sin"

— Islamic law forbids dealing with alcohol in any form, including buying, selling, making, transporting or drinking it — and according to a scholar with Saudi Arabia's Islamic Jurisprudence Academy, your car can't taste the sauce either. Sheikh Mohamed al-Najimi has publicly questioned whether using clean-burning ethanol as a biofuel violates this law, adding further baggage to a renewable energy source already weighed down by a variety of secular concerns.

TIME: "Top 10 Google Earth Finds"

TIME magazine has rounded up 10 amusing or interesting satellite photos discovered via Google Earth. Among the finds are a face-shaped Canadian valley, a shipwreck off the Sudanese coast, a blood-red lake in Iraq and and a possible cruise missile photographed mid-flight.

• LiveScience: "The Shoe Fits! 1.5 Million-Year-Old Human Footprints Found"

— Scientists have found unusually well-preserved, ancient human footprints in Kenya that represent the earliest evidence of modern-human foot anatomy. Belonging to a member of Homo ergaster, the impressions represent a key era in human evolution, as early people's apelike toes uncurled and they began striding the way we do now. The findings are published in today's edition of the journal Science, and have been big news, appearing in outlets such as the AP, New York Times, CNN and BBC

• NASA [photo]: "Moon, Mercury, Jupiter, Mars"

— This photo taken across Tuggerah Lake on the Central Coast of New South Wales, Australia, captures a celestial perfect storm: three planets hanging in the predawn sky next to a crescent moon catching Earthshine, or light from Earth reflected by the moon's night tide.

Russell McLendon

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.