The Greenpeace Cool IT Leaderboard assesses the external impacts and internal efforts of 21 global IT companies to mitigate climate change. While the list has grown, several major companies like Apple and Facebook are absent. The Leaderboard originally took the unique approach of identifying by name each company's chief executive in its listings, but backed off in April 2010. Several years of improvements vanished in 2012, largely due to weak scores for political advocacy. Scores continue to be low in 2012, although most companies did improve.

Specialty metals recycler Umicore uses grams per tonne of gold to illustrate the potential for urban mining of e-waste.

Most ICT gear - core facilities, communications infrastructures, and edge devices - runs on DC power. Converting AC to DC within a building is inefficient, on-site renewable power generation is usually DC to begin with, and super-efficient LED lighting is also DC. So DC power distribution has been a attractive option, but there have been vigorous arguments for and against. Recent events suggest the tide is turning in favor of DC distribution, although skeptics continue to press their case. The growing use of solar-generated electricity might be providing the latest boost DC.

Image courtesy IEEE Spectrum

"Were America's Millions of Analog TVs Recycled?" That's the question we began asking five years ago as the United States converted from analog to digital television (DTV), obsoleting the traditional CRT-based sets. The answer now appears to be "no" due to consumer behavior and a declining market for CRT by-products.

GreenTouch published in May 2013 its Green Meter research study. "The analysis indicates that net energy consumption in networks can be reduced significantly—up to 90 percent—by 2020. The study takes into account new technologies, architectures and protocols, as well as the dramatic increases anticipated in communications traffic over the next decade."

I've noted that research labs are examples of ICT faculties that consume considerable energy. I've also noted communications gear giant Cisco's work on Green ICT. These two topics have come together as Cisco turns its attention to energy use in its own labs.

The NCAR-Wyoming Supercomputing Center (NWSC) in Wyoming "provides advanced computing services to scientists studying a broad range of disciplines, including weather, climate, oceanography, air pollution, space weather, computational science, energy production, and carbon sequestration. It also houses a landmark data storage and archival facility that will hold, among other scientific data, unique historical climate records." It has also become of the focus our largest Twitter discussion of the 2013.

We've been tracking the growth in mega-datacenters since 2009. These faculties feature technical and operational innovation that has overturned previous notions of limits on energy efficiency. But does the focus on efficiency obscure an acceleration in ICT energy and water consumption and in CO2e production? While mega-data center operators are claiming exceptional power usage effectiveness (PUE) ratios, we're still talking about facilities that consume 20-200 MW apiece and emit a considerable carbon footprint unless powered by renewable energy. Here's our most recent look at their reported PUE and the technology behind them, including the addition of a government supercomputer center that highlights subtle issues of efficiency versus sustainability.

How much gear is attached to the edges of our global ICT infrastructure? Our estimate has now reached 17 billion items, driven by mobile and broadcast devices. The World Bank tells us that the western hemisphere now has more mobile phones than people. This is an average number; 30% of Latin America's population lack access to mobile services.

City governments can show Green ICT leadership. Here is what Paul Kronberger is CIO of Madison (WI-USA), a city of 270,000 residents, tells me the municipality has done to improve the sustainability of its own operations.