Without question American CO2 emissions have plummeted, even after being driven into more coal usage due to political concerns about nuclear energy. Cleaner natural gas made the difference but environmental critics say the energy emissions burden simply shifted to developing nations - poor people can't have air conditioning. 

Yet a new study in Nature Climate Change shows that environmentalists don't need to be criticizing the world's poor.  Improving household electricity access in India over the last 30 years contributed only marginally to the nation's total carbon emissions growth.   

Natural gas finally fulfilled its environmental promise this century. Long touted by environmentalists for being much cleaner than coal, hydraulic fracturing - fracking - made it economically viable as well.

The resulting boom also offset the lingering economic malaise in America for states, like Pennsylvania, that embraced it. Poor people could still afford energy but CO2 emissions went back to early 1990s levels, while coal, which had skyrocketed in use when nuclear energy was banned in America, was suddenly back at 1980s levels.

A new device invented at The Ohio State University is the world's first hybrid solar generator and battery - it solves the problem of finicky solar power generation by having the storage built in.

The key is a mesh solar panel, which allows air to enter the battery, and a special process for transferring electrons between the solar panel and the battery electrode. Inside the device, light and oxygen enable different parts of the chemical reactions that charge the battery.

BedZED in Hackbridge, London. Credit: Tom Chance, CC BY-SA

By Melissa C. Lott, University College London

The primary goal of home energy efficiency initiatives might be to reduce total energy consumption, but these projects could have a negative impact on public health if we do not take care.

There is nothing inherently superior about natural gas from hydraulic fracturing - fracking - it has the same emissions as regular natural gas. But it is a lot lower than coal and does not have the political baggage of nuclear energy and that is why environmentalists lobbied for it over the last 40 years.

We live in a battery world - just visit any airport and see people huddled around a wall outlet to witness our battery culture. Yet batteries haven't made any real improvements in decades and that holds back electric cars and solar energy and laptop computers.

An old technology may finally have come of age that can help us enter the world of 21st century portable electricity - betavoltaics, a battery technology that generates power from radiation, has bee created using a water-based solution, and it might be the longer-lasting and more efficient nuclear battery we need.

"Nobody understands the cloud," shouts a character in a recent comedy about a couple trying to remove a private video from the Internet. 

In reality, the cloud is completely understandable, and it's one of few areas in climate where the emissions costs are also. And because it is quantifiable it can benefit from combinatorial optimization. the famous rucksack problem where a traveler has to try and fit everything in without leaving anything behind.

A strange thing happened during climate change policy debates: Advances in hydraulic fracturing - fracking - put trillions of dollars' worth of previously unreachable oil and natural gas within humanity's grasp, and using it led to reductions in CO2 in the United States.

There are numerous methods for maintaining electricity supply when renewables are in the grid. Credit: Johan Douma/Flickr, CC BY-NC-SA

By Anthony Vassallo, University of Sydney

The recent review of the Australian Renewable Energy Target has once again raised the issue of the “unreliability” of some renewable power sources such as wind and solar power.

Image credit:  FeeBeeDee via flickr Rights information: By: Laurel Hamers, Inside Science

(Inside Science) -- Today, ethanol is routinely made from the kernels of corn. Eventually, though, it may be made from the husks.

Starches like corn provide quick energy because they readily break down into simple sugars such as glucose. This structure also makes them easy to convert into bioethanol, an alternative to fossil fuels.