Albedo Enhancement

Albedo Enhancement

The Albedo, AKA the Bond Albedo, is the average reflectance of the Earth.  The Oceans are poor reflectors, only about 8%, so mirrors or white balls make a big difference.  Ice is very reflective so loss of ice is a major cause of albedo decline.

The Albedo reflectance is linked but is quite different from the Greenhouse Effect

Engineers have suggested a sunshade at the L1 Lagrange point between here and the sun, where gravity is zero. But can that be done soon enough? It has to be delivered by many, many rockets, decelerated, stabilised, and deployed. It has to be huge, thousands of square kilometres in size. That L1 point is 1.5 million kilometres away from us.

Maybe such a space sunshade is a long term solution like capturing CO2 or evolving a better species of Homo Sapiens. Massive Atmospheric SO2 has also been suggested. It may well be part of the solution.  Pushing SO2 back into the atmosphere risks acid rain.

But here is another idea:

We release floating reflective balls into the Pacific, into the zone where currents trap floating objects, we make a huge floating mirror to correct the loss of albedo. The balls are reflective croffles.

Trillions of croffles,  AKA shade balls.  

 The Earth Disc and Albedo: our sun sends, mostly in the visible range, about 1367 watts per square metre toward the Earth disc, which is the circle exposed to the sun. Of course the Earth is rotating. The Earth then radiates far infra red light out toward space.

As well as radiating, the Earth is reflecting sunlight. This reflectance is called the Albedo. Oceans, 70% of the surface, reflect only 8%, ice at the poles and coastal clouds reflect much more. Cloud reflectivity improvement is another idea under review, but the technology is unproven and controversial. Direct action as a mirror on the ocean seems more feasible. 

If the albedo is going down, as it is, then more energy from the sun is being absorbed. This heat is mostly collected in the oceans. The recent loss of Albedo and methane increase has caused  an energy balance of plus 2  Watts/sq.m which sounds small compared to the insolation but it is very significant. It means higher and rising surface sea temperatures, as we are indeed experiencing.

If we change the albedo to increase it, the energy balance can be corrected. We need about a 1% correction to put the global warming on hold. 1% Albedo is worth about 3.4 Watts/square metre

Otherwise the surface of land and sea must get hotter to raise the radiation back into balance with the greenhouse effect in operation. The greenhouse effect is mostly from water vapour but CO2 and CH4 are the extra gases we have to consider.

We can try to reduce those greenhouse gases or we can increase albedo. Unfortunately reducing our carbon addiction threatens to crash economies and is going much too slowly.