Considering Plan B on Climate Change
Major shifts are underway in the global climate. Centuries of fossil fuel energy consumption have released substantial amounts of carbon dioxide and other greenhouse gasses into the earth’s atmosphere. These gasses act as a natural insulator, trapping in energy that would otherwise be reflected out into space. As a result, the average global temperature has steadily increased since 1975 at a rate of roughly 0.15-0.20°C per decade. Although this may not seem like a significant increase, even small temperature changes in the overall global temperature can have a drastic effect on earth. As NASA notes, a 1-2° drop was enough to prompt the Little Ice Age centuries ago.
Will efforts to curb emissions succeed fast enough to prevent devastating ecological damage? Inventors have been working for years to improve energy efficiency and reduce emissions, but recent studies show that the damage may already be done. Intellectual Ventures (IV) CEO Nathan Myhrvold and Stanford’s Ken Caldeira (an IV Invention Science Fund inventor) published a study in 2012 that suggests carbon already emitted into the atmosphere will cause substantial temperature increases over the next 40 years. So, what’s an inventor to do?
Myhrvold and Caldeira stress that, rather than waving the white flag, their study should prompt increased urgency around the research and deployment of low-carbon energy solutions. One of IV’s own spin-out companies, TerraPower, is helping lead the way on this front with a new type of nuclear reactor that runs on the stockpiles of nuclear waste left by traditional reactors. However, given the slow progress being made in reducing global emissions, it may also be time for inventors to consider a fallback plan. If we can’t reduce our emissions quickly enough, what else can we do to curb global warming?
That’s where geoengineering comes in. Broadly defined, geoengineering is any deliberate, large-scale effort to alter the world’s climate. This generally takes two forms—inventions that capture excess carbon from the atmosphere and inventions that reflect solar radiation before it can be trapped in the Earth’s atmosphere. In addition to our research into alternative energy sources, geoengineering has been the focus of IV’s own invention efforts. Back in 2009, our solar reflection invention—the Stratospheric Shield, or StratoShield for short—was profiled in the book SuperFreakanomics.
The StratoShield could curb global warming by reducing the amount of solar radiation that hits the Earth. Acting as a “hose to the sky,” the StratoShield would deliver a fine mist of aerosolized sulfur dioxide reaching altitudes of 18 miles high. The particles released would fall back to Earth over the course of a year or more, during which time they would act as a shield to reflect a small amount of incoming sunlight back into space before it gets the chance to warm the Earth. Athough the change in sunlight would be imperceptible to human eyes, it would have a substantial cooling effect for the part of the Earth under the shield. Similar effects have been documented following vulcanic eruptions that release sulfur dioxide particles into the stratosphere.
While the StratoShield is not in production or being field tested, it is an example of a geoengineering system that draws on existing technology in a way that has never been explored before. Much more research needs to be applied to this area so that a body of scientific and engineering knowledge exists, should it ever be needed to address a climate emergency.
Tinkering with the atmosphere is something that shouldn’t be taken lightly, but global warming won’t be solved with old ideas and old technology. While inventions like these should be seen as a last resort, they may buy time for the world to complete the transition to cleaner energy systems.
Additional Geoengineering Resources:
David Keith's Homepage at Harvard University
Caldeira Lab at the Carnegie Insitution for Science