Multitasking, Climate Saving Measures

February 22, 2010 – Vol.14 No.49

MULTITASKING, CLIMATE SAVING MEASURES.
by Bruce Mulliken, Green Energy News

On a clear, hot summer’s day a barefoot walk on an asphalt road is a foot-burner: The black surface is absorbing sunlight and heat is radiating into the soles ones’s feet and everything else nearby.

A barefoot walk on a on light gray sidewalk is not so bad, hot perhaps but not burning. Sunlight is being reflected from the light-colored surface, not absorbed.

As a whole our planet is like the street and sidewalk. The dark oceans, which cover most of our home, absorb the Sun’s rays as do the land areas not covered by snow and ice. Those areas that are the glistening white, those cloud tops and snowy icy areas, reflect sunlight back into space where it can do us no harm.

Yet as glaciers and the ice caps shrink (mostly the Arctic cap for the time being) more dark sunlight-absorbing surfaces are being exposed adding warmth to the planet.

The ability to reflect sunlight is known as a change in Earth’s albedo, and it is changing.

But if man is responsible for warming the planet’s atmosphere with his emissions and causing white, reflecting areas to melt and disappear, man can also counteract the changing albedo by adding man-made reflectivity to his surroundings.

The Institute for Governance and Sustainable Development says this about a newly published research paper:

“Increasing the reflectivity or “albedo” of roofs and pavements in urban areas could offset greenhouse gas emissions by a significant amount, according to a paper published last month in Environmental Research Letters. The research performed by scientists at Lawrence Berkeley National Laboratory and NASA’s Goddard Space Flight Center shows that a 25% and 15% increase in the albedos of roofs and pavements, respectively, in urban areas, could lead to an offset of approximately 57 billion metric tons of carbon dioxide.

“Increasing urban albedo is something that should be done now to buy time for implementing other near-term and long-term climate mitigation strategies,” said Durwood Zaelke, President of the Institute for Governance & Sustainable Development.

"Surfaces with high albedo reflect more solar radiation, preventing the radiation from heating the surface and the atmosphere. Introducing “cool roofs” and more reflective paving materials could replace some of the albedo that has been lost through the melting of Arctic sea ice.

“Although it does not solve the root of the climate change problem – substantial reductions in CO2 and other climate forcers are essential for that – urban albedo can delay the onset of more severe climate impacts, and reduce the risk of passing the thresholds for abrupt and irreversible climate changes,” added Zaelke.”

Like a shiny snow cover that keeps a region cool on bright sunny days, adding sunlight reflective surfaces globally would help cool off the entire planet slowing the rise of temperatures, buying time for long term solutions for global warming.

The research paper itself notes in comment that there’s an indirect benefit of adding reflective roofs: The reduced energy demand for air conditioning in the summer is greater than the increase in energy needed to heat a building that is reflecting sunlight from its roof. That is, the cooling energy savings are greater than the heating energy penalties of the loss, through reflection, of sunlight that helps heat a building in winter. (The energy impact on buildings of reflective roofs is beyond the scope of the research paper.)

The Institute for Governance & Sustainable Development also has this to say about mitigating global warming in general:

"Because CO2 emissions can remain in the atmosphere for up to 1,000 years, there is an urgent need for complementary, fast mitigation measures that will result in significant near-term reductions to avoid passing the tipping points for abrupt climate change, which may only be decades away. In addition to increasing urban albedo, such strategies include reducing emissions of black carbon soot, methane, and tropospheric ozone, as well as using the Montreal Protocol ozone treaty to phase down hydrofluorocarbons, which could prevent the emissions of more than 100 billion metric tons of CO2-equivalent by 2050. Carbon-negative measures such as better forest management and production of biochar will also be necessary to bring atmospheric concentrations of CO2 back down to safe levels.”

Note the inclusion, above, of biochar as a carbon negative climate change mitigating measure.

Biochar is already being studied commercially as a soil enhancer or amendment. BlueLeaf and Dynamotive Energy Systems have announced results from two years of agricultural field trials of Dynamotive’s commercial biochar product known as CQuest(tm).

From a joint statement from BlueLeaf and Dynamotive:

“Key results include increases in biomass produced with biochar amended soils versus non-treated control areas. In the case of soybean in 2008, a 20% increase in grain yield was shown and for a forage mixture in 2009 a 100% increase in fresh biomass was obtained. Other parameters showing increases with CQuest Biochar included earthworm, nematode and mycorrhizal root colonization, supporting the hypothesis that biochar may serve as a refuge for soil microbes. Surface soil water infiltration was also greater in biochar amended soil.”

So, reflective man-made surfaces can increase the Earth’s albedo and offset the impact of carbon dioxide increases while those reflective roofs can cut energy consumption in air conditioning reliant zones.

Biochar, too, can multitask. It can store carbon that would ordinarily find it its way into the atmosphere while increasing crop yields as well as create a new source of energy, a type of bio-oil or bio-gas, in its production.

Dynamotive Energy Systems Corporation is an energy solutions provider headquartered in Vancouver, Canada.

BlueLeaf is a social purpose private corporation active in environment issues related to water and agriculture.

Links:

Institute for Governance and Sustainable Development
http://www.igsd.org

A news release at the site includes a link the paper “Radiative forcing and temperature response to changes in urban albedos and associated CO2 offsets by Surabi Menon, Hashem Akbari, Sarith Mahanama, Igor Sednev and Ronnen Levinson”
http://igsd.org/documents/PR_urbanalbedo_19Feb2010.pdf

Dynamotive Energy Systems
http://www.dynamotive.com

Blue Leaf
http://www.blue-leaf.ca

Full details of the Blue Leaf Report
http://www.dynamotive.com/assets/resources/BlueLeaf-Biochar-FT0809.pdf