There are three main ways to stop global warming and climate change from getting worse and that will, one hopes, enable us to manage our global temperature:-
Proposals such as whitening clouds, making clouds, covering large areas with white plastic, increasing the albedo of grasses and plants, reflective dust in the upper atmosphere and space shields of various sorts.
So far, the only use of albedo to be advocated by the UN's IPCC, is to increase the solar reflectivity of our cities based upon the work of Hashem Akbari et al., "The Heat Island Group", in 1998. They advocate doing so because of the energy savings and reduction in associated emissions.
The study, on Los Angeles in the United States of America, showed that for a 7.5% increase in albedo, or solar reflectivity, 50-60% reductions in electricity for cooling, as well as, 30+% reductions in peak loads for air-conditioners, fewer photochemical smog days with reduced health costs and a more pleasant environment around 5 degrees Farenheit cooler, 2.8 degrees Centigrade, could be achieved by strategically planting trees and increasing the albedo of roads, roofs and footpaths, as well as, the walls of many buildings.
Potential savings for Los Angeles are estimated to be half a billion dollars USD annually when health cost savings are included.
Buildings with high solar reflectivity (and low emissivity) use less energy for heating and also last longer than dark coloured structures that are subjected to greater daily extremes of expansion and contraction.
Chicago: Albedo Increase = Temperature Decrease
Chicago began increasing urban albedo and vegetation in 1995. The satellite results show that increasing urban albedo actually brought about an even greater decrease in local temperatures than expected. Visit Chris Mackay's website to view a satellite based comparison of urban cooling strategies.
Chris Mackay et al..
30Gt Emissions Reduction Required
The Heat Island Group's proposal to increase the albedo of our 100 largest cities would provide an estimated 40+ Gigatonne CO2e offset to our global emissions and save on emissions. This would delay catastrophic climate change, hopefully long enough for us to get on track with regards to reducing our emissions.
The graph above is from Art Rosenfeld's PALENC (Passive And Low Energy Cooling) presentation and shows Stern's "Business as Usual" A2 scenario and the required 30 Gt reduction in emissions necessary to keep global warming below 2 degrees Centigrade.
Using solar reflective, high albedo coatings, as well as, painting interior walls with low emissive, reflective paints and using heat reflective window coatings will save up to 60%, or more, on heating and cooling costs for an existing building, as well as, help to reduce a City's heat island. Utilising such materials in new buildings costs little or nothing in most cases.
If we need to "do something" about reducing global warming then choosing solar reflective materials and generally increasing our collective albedo will achieve immediate results. A minimum solar reflectivity requirement in building and road construction codes would be a good start. Australia's minimum 6 star building standard points to high albedo roofs and walls as a way to achieve this standard.
The main benefit of employing solar reflective materials in buildings comes from the large reduction in emissions for electricity and peak loads for heating and cooling, as well as, the enormous health savings and longer life expectancies from reduced photochemical smog in many cities.
Albedo - Global Warming Survival Information Video
Albedov72.zip 1.72 MB (1,805,449 bytes)
The program has no restrictions but "asks" for a donation
- Try the online local albedo offset calculator. It is limited to a maximum area of one square kilometer and outputs a global warming offset in kilowatts, tonnes of CO2 and a dollar value.
Potential CO2e Offsets of Australia's Roads - au_roads.pdf
Potential CO2e Offsets of New Zealand's Capitals - nzcities.pdf
Links to more albedo information:
Hashem Akbari's 100 Cities Presentation
UN's Special Report on Renewable Energy Sources and Climate Change Mitigation (SRREN)
Art Rosenfeld's September, 2007 PALENC Presentation
Plot of Melbourne's UHI "Urban Heat Island"
Painting the town white - and green
Heat Island Group Home Page