Daily Archives: 07/06/2005

Ethanol Not So Green

My buddy who got his car stolen last month is looking into buying a Prius and I think that’s pretty damn cool. Gasoline prices are rising on Guam again; a gallon of regular unleaded is currently $2.609 at island pumps. I keep saying I’m going to start taking the bus, but it hasn’t happened yet. Probably because I’d need to walk two miles to the nearest bus stop.

Anyway, I found a little story about how ethanol and other alcohol based fuels are not so ecologically friendly after all. The main complaint is that growing corn or sugar cane for fuel contributes to soil erosion and monoculture crops reduce biodiversity. The article doesn’t bother to mention the vast amounts of petroleum based fertilizers used to grow these crops, which are certainly not sustainable. Still, I wouldn’t mind driving around with an 85% ethanol blend in my tank, if it was significantly cheaper than regular gasoline.

One If By Land, Two If By Sea

Scientists have identified the earliest human footprints ever found in the New World, a series of footprints laid down in volcanic ash over 40,000 years ago. Conventional anthropological theory states that humans arrived in the Americas during the last great glaciation, at the end of the Pleistocene around 12,000 years ago. Some sites in both North and South America challenged that claim, but none so spectacular as these Mexican footprints.

Dr. Sylvia Gonzalez and her team found the footprints in a quarry near the city of Puebla in 2003. They took their time dating the materials, knowing the results would be controversial:

The researchers used radiocarbon dating on shells and animal bones in the sequences and dated mammoth teeth by a technique called electron spin resonance. The sediments themselves were dated by optically stimulated luminescence.

“Some lake sediments were incorporated into the ash and were baked. They look like small fragments of brick and these were the ones we dated in the footprint layer. They gave us a result of 38,000 years,” Dr Gonzalez.

The article points out that Dr. Gonzalez proposes an island hopping sea voyage undertaken by these earliest Americans. This oceanic theory suggests that early hunters worked their way around the Pacific Rim, hopping from coastal island to coastal island to reach the New World, instead of walking across the Bering Land Bridge. Who knows? The land bridge was exposed several times during the Pleistocene, both before 35,000 years ago and 15,000 to 11,000 BPE. Any evidence of coastal migration is beneath 300 feet of chilly water, while the overland passage between the ice sheets was scoured clean in later glaciations.