There’s a lot of discussion right now about climate change and global warming. The announcement that the first decade of the 21st century has been the hottest ever recorded fuels the fire. And whether you believe human activities are causing the heat or not, one thing’s for sure – rising global temperatures are not a good thing. They raise sea levels, exacerbate droughts and affect crops and water supplies.

Given that temperatures are rising, and that this rise is going to cause problems, what can human beings do to change things? One solution might be to cut back on greenhouse gas emissions. But that hasn’t gone so well. Emissions of carbon dioxide are up 29% since 2000.

One geoengineering approach that would reflect sunlight in the upper atmosphere tries to replicate a natural phenomenon. We know that after big volcanic eruptions, global temperatures fall. For example, after the eruption of Mount Pinatubo in 1991, global temperatures fell about 1 degree F because of all of the dust and sulfur dioxide injected into the upper atmosphere. The sulfur dioxide turns into droplets of acid at high altitude that absorb and reflect sunlight. Perhaps 10% less sunlight reached earth’s surface after the eruption, and the effect lasted for more than a year.

Therefore, it is possible to imagine cooling planet earth by creating machines that inject sulfur dioxide into the upper atmosphere. That is the goal of the Stratoshield, – balloons carry hoses aloft and we pump sulfur dioxide up from the ground. The drop in sunlight reaching the earth’s surface cools the planet.

Introducing the Stratoshield

Scientists have proposed a wide variety of approaches for cooling part or all of the Earth [Blackstock et al. 2009]. One approach has received more attention than the others, however: the idea of increasing the amount of sulfur-bearing aerosols in the stratosphere and thereby decreasing slightly the amount of sunlight that reaches the earth [Kunzig 2009]. (The stratosphere is the weather-free portion of the atmosphere at altitudes between about 10 kilometers and 50 kilometers, or 33,000 to 165,000 feet.)…

sulfur dioxide aerosols appear to remain in the stratosphere for only a year or two after injection before falling back to Earth [Caldeira and Wood 2008]. Any geoengineering system should ideally be not only quick-acting but also quickly reversible, so that the climate returns to its previous state soon after the system is turned off. This provides a measure of safety in case any damaging side effects appear when the system is deployed.

This video describes the Stratoshield and shows one possible implementation:

See also:

For more info see:
- 56 newspapers in 45 countries published the same editorial today, so it must be something important…
- How Global Warming Works
- What are green-collar jobs?

[[[Jump to previous invention - Head-mounted camera records all police interactions]]]