Yes, it is due to global warming!

A glance through climate change news will show the growing gap between believers and deniers even today. Is the climate disruption we are witnessing linked to global warming, is still contested. New research released yesterday links human-caused climate change to six of 12 extreme weather events from 2012. Teams of scientists from around the world examined the causes behind extreme weather events on five continents and in the Arctic. Their results were published as a special report in the Bulletin of the American Meteorological Society.

One of the stronger linkages between global warming and severe weather was found in an analysis of last year's high July temperatures in the northeastern and north-central United States. The Stanford team found that climate change had made the likelihood of such a heat wave four times more likely than in a world without elevated levels of greenhouse gases. They were able to determine this by running models with current levels of greenhouse gases as well as ones that reflected preindustrial levels and examining the relative likelihood of the heat wave.

Others looked at 2012's hot spring temperatures over the eastern United States and also found that human influences contributed about 35 percent to late spring heat that year.

In some other parts of the world, climate change was linked, although in a small way, to extreme precipitation events. New Zealand experienced an extreme two-day rainfall in December 2011; researchers said 1 to 5 percent more moisture was available for that event due to climate change, which is increasing the amount of water vapor in the atmosphere.

Australia also experienced record rainfall in early 2012, and while La Niña, a natural variation, was behind much of that, researchers found that human-caused climate change increased the chance of the above-average rainfall by 5 to 15 percent.

This is the second time the Bulletin of the American Meteorological Society has collected information on the previous year's weather extremes and tried to tease out the role of climate change in those events. The researchers involved in the effort stressed that the science of attribution, or of linking specific events to climate change, is still young and evolving.

New AC technologies to cut power use

The U.S. expends roughly 185 billion kilowatt-hours of energy each year on home cooling, the most by any nation in the world. Air conditioner sales are growing globally by roughly 20 percent per year, with the newly affluent in China and India leading the way. How do we beat the heat without increasing that heat through global warming caused by burning fossil fuels to power the air-conditioner? The U.S. Advanced Research Projects Agency for Energy, ARPA–E, hopes to cut this hot forecast by reducing the energy required for air-conditioning.

Conventional air-conditioners employ refrigerants such as chlorofluorocarbons to absorb heat from the room to be cooled. That heat is then expelled outside, requiring electrically powered pumps and compressors. One idea to conserve energy is to replace coolant fluids and gases—which are often super-powered greenhouse gases capable of trapping more than 1,000 times more heat than CO2—with solid materials, such as bismuth telluride. 

A new device uses electricity to change a thermoelectric solid to absorb heat, and could lead to cheaper air-conditioners or refrigerators. Such refrigerators, which lack moving parts and are therefore less likely to break down, can be lifesavers in remote, rural areas for keeping medicines cool or food fresh.

Another approach is to employ specialty membranes to cool air by condensing water. These technologies are being developed by companies and now have acquired backing from the U.S. Navy, which requires efficient air-conditioners and dehumidifiers for both troops and equipment in hotspots such as Iraq and Afghanistan. "A 30 percent improvement in efficiency means 30 percent less fuel to drag to the front," Martin notes, adding that the Navy program aims for units that use 20 to 50 percent less fuel.

More efficient air-conditioners can provide cooling that could prove vital for people trying to adapt to more extreme heat waves in the future, whether in the U.S. or India. Meanwhile, a simple approach to cut down the HVAC bills would be to keep the knob a level higher than freezing temperatures - a practice in many places!

Storing RE not always sensible

Renewable energy holds the promise of reducing carbon dioxide emissions. But there are times when solar and wind farms generate more electricity than is needed by consumers. Storing that surplus energy in batteries for later use seems like an obvious solution, but a new study from Stanford University suggests that might not always be the case. The costs involved in terms of energy are too high.

Grid-scale batteries make sense for storing surplus solar energy, but not for wind they found. The study, which is supported by GCEP, is published in the online edition of the journal Energy and Environmental Science.

The Stanford team looked at several emerging technologies, including five battery types -- lead-acid, lithium-ion, sodium-sulfur, vanadium-redox and zinc-bromine. Batteries with high energetic cost consume more fossil fuels and therefore release more carbon dioxide over their lifetime. If a battery's energetic cost is too high, its overall contribution to global warming could negate the environmental benefits of the wind or solar farm it was supposed to support.

The researchers compared the energetic cost of curtailing solar and wind power, versus the energetic cost of grid-scale storage. Their calculations were based on a formula known as "energy return on investment" -- the amount of energy produced by a technology, divided by the amount of energy it takes to build and maintain it.

Using that formula, the researchers found that the amount of energy required to create a solar farm is comparable to the energy used to build each of the five battery technologies. The results were quite different for wind farms. The scientists found that curtailing wind power reduces the energy return on investment by 10 percent. But storing surplus wind-generated electricity in batteries results in even greater reductions -- from about 20 percent for lithium-ion batteries to more than 50 percent for lead-acid.

As the team notes, it is important for society to be energy-smart about implementing new technologies.  When plunging into new technologies, policymakers and investors need to consider the energetic cost as well as the financial cost of new technologies.

Productivity to go down as the globe warms

A new NOAA study projects that heat-stress related labor capacity losses will double globally by 2050 with a warming climate. Recent studies project a collapse in labor productivity from business-as-usual carbon emissions and warming — with a cost to society that may well exceed that of all other costs of climate change combined.  A 2 percent drop in productivity per degree rise is how the US study sees it. How about in hotter climes then??

Is it possible to reduce emissions 50 percent globally by 2050s? Only one country, France, has ever reduced greenhouse emissions at the pace we’d have to keep up between now and 2050. Over a remarkable period of 30 years, France went from getting less than 1 percent of its power from nuclear power plants (which emit no carbon dioxide directly) to getting about 80 percent from them. During the period of the fastest nuclear build-out, France managed to reduce emissions at a rate of 2 percent per year, says David Victor, co-director of the Laboratory on International Law and Regulation at the University of California, San Diego. But the transition was tough.

This kind of transition for the rest of the world could be tough to almost improbable. Look at what’s happened in the United States. A major recession slowed energy consumption, and at the same time technological advances unlocked huge amounts of natural gas, leading utilities to shut down coal plants in favor of natural-gas plants that emit half as much carbon dioxide. In just one year, 2009, emissions dropped by an impressive 6.7 percent. But that was only across one year. If you look back to 2000, the average reduction was less than 1 percent a year, less than half of what’s needed to meet emissions goals! Looks like the human race better get set for tough times ahead.

Random wins over order!

The US electrical grid is in danger of breaking down, thanks to orderly networks!

A mathematical study of spatial networks by physicists in Israel and the U.S. says that the research builds on earlier work by incorporating a more explicit analysis of how the spatial nature of physical networks affects their fundamental stability. The upshot, published August 25 in Nature Physics, is that spatial networks are necessarily dependent on any number of critical nodes whose failure can lead to abrupt—and unpredictable—collapse. The electric grid, which operates as a series of networks that are defined by geography, is a prime example. Whenever you have such dependencies in the system, failure in one place leads to failure in another place, which cascades into collapse.

Focussing on idealized scenarios, the team found that randomly structured networks—such as social networks—degrade slowly as nodes are removed, which in the real world might mean there is time to diagnose and address a problem before a system collapses. By contrast, the connections of orderly lattice structures have more critical nodes, which increase the instability. The problem is that such orderly networks are always operating near an indefinable edge. To reduce that risk, they recommends adding a small number of longer transmission lines that provide short cuts to different parts of the grid.

The 2003 blackout stemmed from a combination of bad vegetation management—the first three lines tripped after sagging into trees but were all within their load rating—and a series of monitoring and communications breakdowns. Vegetation requirements have since been standardized, and a new generation of sensors is providing grid operators with more information about what is happening across the grid at any given moment.

Abundant and cheap source

University of Alberta researchers have found that abundant materials in Earth's crust can be used to make inexpensive and easily manufactured nanoparticle-based solar cells. At the university’s National Institute for Nanotechnology, the team has designed nanoparticles that absorb light and conduct electricity from two very common elements: phosphorus and zinc. Both materials are more plentiful than scarce materials such as cadmium and are free from manufacturing restrictions imposed on lead-based nanoparticles.

The research supports a promising approach of making solar cells cheaply using mass manufacturing methods like roll-to-roll printing (as with newspaper presses) or spray-coating (similar to automotive painting). Nanoparticle-based 'inks' could be used to literally paint or print solar cells or precise compositions, the scientist said. The team was able to develop a synthetic method to make zinc phosphide nanoparticles, and demonstrated that the particles can be dissolved to form an ink and processed to make thin films that are responsive to light.

The team is now experimenting with the nanoparticles, spray-coating them onto large solar cells to test their efficiency. The research in this field is tremendous as can be seen with the studies being published. The day is not far off when the planet will be truly living off its star!