Renewable energy - not so renewable?

An interesting article from the Bulletin of the Atomic Scientists pointing out that no energy source is entirely renewable - there is always a cost for extracting and utilising the energy, sometimes quite significant.

"Renewable energy sounds so much more natural and believable than a perpetual-motion machine, but there's one big problem: Unless you're planning to live without electricity and motorized transportation, you need more than just wind, water, sunlight, and plants for energy. You need raw materials, real estate, and other things that will run out one day. You need stuff that has to be mined, drilled, transported, and bulldozed -- not simply harvested or farmed."

As these costs change with new technologies, constant re-assessment and balancing of pro and cons needs to be standard procedure.

And, of course, reduced and more efficient energy use is always a wise option.

The Decline of Violence

According to a recent book our times are less violent than in historical times. The book is called “The Better Angels of Our Nature: Why Violence Has Declined” and is by a well-known professor of psychology, one Steven Pinker. A review of the book by Scientific American reports an interview as follows:

COOK: What would you say is the biggest misconception people have about violence?
PINKER: That we are living in a violent age. The statistics suggest that this may be the most peaceable time in our species’s existence.

His conclusions are not uncontroversial but he makes a convincing and very interesting case.

Global warming science 150 years ago

Back 150 years ago John Tyndall discovered the 'greenhouse effect' which is the basis of global warming. He also made other significant scientific discoveries. This BBC report describes this and mentions the Tyndall Conference taking place. This news item certainly highlights the importance of decision-makers understanding the implications of scientific discoveries.

3D printing

Have you heard of this? Most people have not but it is an exciting area of technology destined to have a major impact.
According to one definition it is "a form of additive manufacturing technology where a three dimensional object is created by laying down successive layers of material".
Basically you take a digital file (e.g. from an email), give it to the 3D printer and it recreates an object from scratch out of a polymer.
Here is an article on it from Wikipedia.

Technologies for reducing carbon emissions

An article at NextBigFuture lists "Ten Technologies that should have a big impact on Green house gas Emissions".
See PhysicsSubset blog for this.