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Well, for each gallon of gas you burn in your engine, there's the climate equivalent of another quarter-gallon or so embedded in your consumption.

Remember when you were a kid and your parents made a big fuss about turning off the light when you left a room? Who knew that, besides adding to the monthly electric bill, keeping a single 60-watt lightbulb lit for 12 hours uses as much as 60 liters of water? According to researchers at the Virginia Water Resources Research Center, in Blacksburg, Va., fossil-fuel-fired thermoelectric power plants consume more than 500 billion L of fresh water per day in the United States alone.

Biofuels, once seen as a useful way of combating climate change, could actually increase greenhouse gas emissions, say two major new studies. And it may take tens or hundreds of years to pay back the "carbon debt" accrued by growing biofuels in the first place, say researchers. The calculations join a growing list of studies questioning whether switching to biofuels really will help combat climate change.

Take a good look at panels that have been installed for several years and you will notice discontinuities and shiny areas where the components have been damaged and where the power production is reduced.

Though there are no visibly moving parts in a solar PV panel, there are many parts of the system where continuous chemical and physical reactions take place that can eventually lead to system degradation and failure.

Leaves and snow are particular nuisances for rooftop solar panels, but sand and bird droppings can be important in some areas as well.

A new life-cycle assessment study from the Brookhaven National Laboratory in New York examined the four most common types of photovoltaic (PV) solar power cells - multicrystalline silicon, monocrystalline silicon, ribbon silicon and thin-film, if you were wondering - to find out how much energy and waste was involved in their creation.

True or false: taking the commuter train across Boston results in lower greenhouse gas emissions than travelling the same distance in a jumbo jet. Perhaps surprisingly, the answer is false. A new study compares the "full life-cycle" emissions generated by 11 different modes of transportation in the US. Unlike previous studies on transport emissions, Mikhail Chester and Arpad Horvath of the University of California, Berkeley, looked beyond what is emitted by different types of car, train, bus or plane while their engines are running and includes emissions from building and maintaining the vehicles and their infrastructure, as well as generating the fuel to run them.

According to the NREL report referenced above, converting biomass into cellulosic ethanol can be done at about a 45% efficiency (i.e. 45% of the energy of the biomass makes it into the fuel.) In contrast, biomass can be converted at 33-37% efficiency [pdf] when cofired. Combining this with the 5x improvement of drivetrain efficiency that comes with electric propulsion, and the same amount of biomass converted to what I'll call "cellulosic electricity" will take a vehicle 3.8x as far as it would in the form of cellulosic ethanol.

Photovoltaic (PV) technologies have shown remarkable progress recently in terms of annual production capacity and life cycle environmental performances, which necessitate timely updates of environmental indicators. Based on PV production data of 2004–2006, this study presents the life-cycle greenhouse gas emissions, criteria pollutant emissions, and heavy metal emissions from four types of major commercial PV systems: multicrystalline silicon, monocrystalline silicon, ribbon silicon, and thin-film cadmium telluride. Life-cycle emissions were determined by employing average electricity mixtures in Europe and the United States during the materials and module production for each PV system. Among the current vintage of PV technologies, thin-film cadmium telluride (CdTe) PV emits the least amount of harmful air emissions as it requires the least amount of energy during the module production. However, the differences in the emissions between different PV technologies are very small in comparison to the emissions from conventional energy technologies that PV could displace. As a part of prospective analysis, the effect of PV breeder was investigated. Overall, all PV technologies generate far less life-cycle air emissions per GWh than conventional fossil-fuel-based electricity generation technologies. At least 89% of air emissions associated with electricity generation could be prevented if electricity from photovoltaics displaces electricity from the grid.

n aluminum can costs about a cent. Almost worthless, so it’s easy to toss it in the trash. It's like a magic trick, if you think about it. The thousands of stages in the manufacturing process, the material costs and the human stories, disappear into the air when we only have to spend a cent.   It’s how environmental catastrophes happen. We can’t see how unsustainable some products really are - because when they come in packs of 10 for a buck, who would be crazy enough to sell our planet off so cheaply? Separating price and value requires a shift in perspective. Things are often cheap because companies have figured out ways to externalize their true costs. Here's a look at what it really takes to make 10 everyday items we all use.