Geoengineering Strategy Increase the Planetary Albedo

On June 15, 1991, Mt. Pinatubo, a volcano in the Philippines, explosively erupted. The volcanic plume lofted approximately 20 Tg of gaseous sulfur dioxide into the upper troposphere and stratosphere. During the subsequent weeks, the volcanic sulfur dioxide dispersed across the globe, while photochemically oxidizing to form sulfate aerosols. These aerosols had both significant "direct" and "indirect" effects on the Earth's radiative balance - directly scattering solar radiation to outer space and indirectly affecting climate by enhancing cloud reflectivity in the upper troposphere. Two months after the eruption, the Earth's albedo had increased, on average, by 6%. Cloud-free regions, which otherwise absorb a large fraction of the earth's incoming solar energy, saw a 20% increase in albedo due entirely to direct aerosol scattering. In the year to follow, global temperatures dropped by an estimated 0.7°C (relative to 1991). As the volcanic aerosols settled out of the stratosphere and processed out of the troposphere by wet and dry deposition, the cooling effect faded. By 1993, the temperature anomaly had decreased by half ([23] and references therein).

Many in the scientific community view the 1991 eruption of Mt. Pinatubo as a natural demonstration of the geoengineering strategy for managing climate warming through the enhancement of planetary albedo. The cooling effect of volcanic eruptions has inspired proposals to inject aerosols into the stratosphere and, as with the volcanic emissions, increase the amount of back-scattered solar radiation at the top of the atmosphere. Other proposals to increase the Earth's albedo include brightening tropospheric clouds overlying the ocean and widespread modification of the ocean and/or land surface.

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Getting Started With Solar

Getting Started With Solar

Do we really want the one thing that gives us its resources unconditionally to suffer even more than it is suffering now? Nature, is a part of our being from the earliest human days. We respect Nature and it gives us its bounty, but in the recent past greedy money hungry corporations have made us all so destructive, so wasteful.

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