Unfortunately, history suggests that top-down, bureaucratic efforts in the face of long term threats are likely to fail.

Yet a simple ”trim tab” adjustment may alone buy humanity sufficient time to discover and implement an affordable solution.

Most approaches focus on reducing the cause of added warmth- greenhouse gases- which trap infrared light in the atmosphere. For example, one mitigation strategy promotes solar photovoltaics as they do not emit CO₂, and thus function as clean energy substitutes for fossil fuel. Unfortunately, in 2007 only about 2 GW of solar will be installed worldwide, while China alone builds 2 GW of coal plants every week. Wind, bio-fuels etc. all face similar challenges of inadequate scale, while suffering from long payback cycles and installation times.

Alternatively, one can focus on the source- that is, by reducing solar fluence hitting the earth’s surface. Of the 1380 watts per m² impinging on the atmosphere, only to be absorbed and reflected by various layers of air, clouds, land and water- greenhouse gases retain an additional 1.8 Watts/m² over pre-industrial levels. If, somehow the earth’s average albedo could be increased by the same fraction- say 0.3%, it could provide temporary relief while long term, affordable solutions are found to satisfy our growing appetite for energy, without producing excess methane and CO₂[*].

We propose a simple, inexpensive, low technology, distributed solution. Enroll all 6 billion people on earth to help make their world a little brighter. By reflecting a bit more sunlight into outer space, the earth will cool.

As an extreme example of what is possible- imagine a property owner converting a flat black warehouse roof top to mirrors. While 90% of visible light would reflect back into the air (and thus could in principle pass through the atmosphere back into space), only about 60% would make it past clouds, water vapor, dust, etc. More realistically, on average every day 200 W/m² of visible light hits the surface of the earth, and only 30 W/m² is reflected. But after painting the roof white, an additional 90 W/m² might leave the atmosphere, or about 50x (e.g. [90w/m²]/[1.8w/m²]) more than the excess heating from global warming in that same square meter.

By this simple illustration, one square meter of high reflectance eliminates the effect of 90 m² of atmospheric CO₂. At 100 ppm of excess CO₂, this is equivalent to about 100 pounds of CO₂. More precise models and calculations by the team at the University of Perugia suggest 10-20 m² of white painted surfaces compensates for one ton of CO₂ (depending on latitude and other factors).

Our approach is also affordable. A square meter of solar panels costs $500- white paint, perhaps $1. Other mitigation techniques cost even less- simply choosing to install a white roof instead of gray in new-home construction.

If one billion people could each convert 10 m² of black or gray surfaces to white, they could offset ONE BILLION METRIC TONS of CO₂. Repeated over a decade, it’s just possible to imagine completely offsetting humanity’s carbon footprint, at least in the short term. No other approach can be as effective, as inexpensive, as widely implemented, as quickly.

The list of EarthLight Project ideas ranges from the simple to the sublime:

• White roofs replacing black or gray. (The average US home has 60 m² of south-facing roof).
• White patio umbrellas, instead of brown.
• White playground sand, instead of brown.
• White cars, offsetting some of their own CO₂ emissions.
• Using white concrete aggregate instead of bluestone in asphalt paving. There are 8 million lane-miles (200 m² per capita) in the US alone.
• Planting lighter grasses for dark green, in parks and homes.
• Painting asphalt parking lots white.
• Snow-blow, instead of plow, to encourage deeper snow cover on roadsides.
• Reducing air pollution, which darkens snow and soil.

Advantages:

• Every person on the planet can contribute locally in an appropriate and affordable way.
• The ubiquity and visibility of local solutions provide a constant reminder of the global warming problem, as well as a source of diverse ideas that can be imitated, modified and improved.
• Easy for individuals, community groups, NGOs and governments to sponsor local challenges and provide support and perhaps subsidies.
• Global, rather than local, albedo change is less likely to create unintended environmental damage.
• Easily reversed if necessary.
Potential disadvantages:
• Negative weather events may be blamed on the EarthLight Project, and in worse case could cause rioting or other disruptions.

The Plan. It is presumptious to assume we know the best way to implement our suggestion, especially given the wide range of cultures and economies involved. But we can suggest a path that will lead to wisdom:

• Within 6 months hold an international EarthLight Project conference with broad organizational participation.
• Embrace the power of communications networks, particularly the internet and community groups, to open conference to input from all citizens.
• Share, improve and disseminate the best solutions.
• Design a world-wide measurement system to determine the extent of albedo increase.
• Work to have albedo increases qualify for carbon credits.
• Publicize progress.
• Evolve as we learn.

Profiles:

Greg Blonder is an inventor, scientist and a Partner at Morgenthaler Ventures. Even in high school Greg was advocating more efficient forms of energy generation- building a two-axis parabolic concentrator and heater a year before the first energy crisis (the heater was housed in a clear Plexiglas geodesic dome, built by following the teaching of Buckminster Fuller’s original patent). Today, he has invested in a number of clean tech companies, and continues to write and lobby on behalf of greater energy efficiency and lower human impact on nature.

Greg attended the Massachusetts Institute of Technology (M.I.T.) where his undergraduate thesis was on phase transitions in liquid crystals. In 1982 he received his MS and Ph.D. in Physics from Harvard University.

In 1982 he joined AT&T Bell Labs, eventually leading the Photonics and the Materials Science divisions. Much of this research resulted in practical applications and he holds over 80 patents in the areas of optical disk recording, solid state lighting, displays, toys, computer systems and improved user interfaces.

In 1992 he assumed the additional responsibility of Chief Technical Advisor for Corporate Strategy and Development, where he was involved in selecting technical and business strategies for AT&T. In 1995, recognizing the need to focus Bell Labs research activities closer to consumer markets, he started the Customer Expectations Research Lab. This lab tries to understand human behavior through a variety of statistical and cognitive techniques- and then relate those needs to future products and services. They also pioneered a quantitative approach to scenario planning, which has been adopted by a number of companies, and broadly provides a framework behind this proposal’s thinking.

Franco Cotana is full professor of Applied Physics at the University of Perugia and director of CRB (Biomass Research Center). He is author of over 150 scientific publications in research journals and congress proceedings on environmental and energy subjects (energy saving, environmental comfort, heat transmission, applied thermodynamics, heating and air conditioning of buildings, etc.).

Current research activity is focused on low environmental impact transport systems and Earth’s energy balance. In this connection a company has been created, called Pipe§net SRL, which purpose is to study, develop, patent and manufacture both innovative freight transport systems (Pipe§net exactly) and solutions for global warming control. In 2006 an original relation has been patented by Pipe§net SRL (patent n. PG 2006 A 0086) that correlates reflecting surfaces extension and corresponding average atmosphere temperature decrease; furthermore in the patent a ratio between greenhouse gases emission, in terms of equivalent carbon dioxide, and reflecting surfaces extension is also introduced.

[*Note on calculations: Global warming predictions continue to improve, but are still model dependent. For example, water vapor is the largest single global warming gas, but it's hard to predict the effect of temperature, agriculture, etc on humidity levels. Similarly, biofuels may increase global warming by shifting the balance of greenhosue gases towards methane. For this reason we've suggested a "mechanical" solution to the problem by reducing levels at the source. Never the less, factors of two or three uncertainties remain].

Related work:

Comparing the efficiency of solar cells to white paint in mitigating global warming

Laboratory measurement of the effect of albedo on solar warming