Global warming statistics and facts
ARTIFICIAL VOLCANO: Could mimicking a massive volcanic eruption, like that of Pinatubo in the Philippines in 1991, avoid global warming?
A global deal to combat climate change lurches toward reality in Lima, Peru, this week—and yet any politically feasible agreement will be insufficient to restrain continued warming of global average temperatures, perhaps uncomfortably high. Although recent pledges by China, the 28 countries of the European Union and the U.S. are the first signs of the possibility of restraining the endless growth of greenhouse gas pollution on a long-term basis, atmospheric concentrations of carbon dioxide have crossed the threshold of 400 parts per million—and will reach 450 ppm in less than two decades at present growth rates. The estimated one trillion metric tons of carbon the atmosphere can absorb could be burned through in even less time, particularly if India, as it develops, picks up where China leaves off by burning coal without any attempt to capture the CO2 before the greenhouse gas spews from smokestacks.
The world may find itself in need of another alternative, such as geoengineering, if catastrophic climate change begins to manifest, whether in the form of even more deadly heat waves, more crop-killing droughts, more rapid rises in sea level or accelerating warming as natural stores of carbon—such as the ocean’s methane hydrates—melt down, releasing yet more greenhouse gases to drive yet more climate change.
So maybe the answer is to genetically soup up plants so they can pull more CO2 out of the air and then bury them at the sea bottom? Or give the planet a giant sunshade, whether in the form of more clouds or a haze of light-reflecting sulfur bits floating in the stratosphere? "In a crisis the temptation will be to use the quick fix of geoengineering, " argued economist Scott Barrett of Columbia University at a research symposium on CO2 capture technologies this spring.
If civilization continues, the unplanned, undirected geoengineering of the climate via burning fossil fuels—whether coal in a power plant or oil sludge in a massive container ship steaming across the Pacific—then perhaps nations will need to plan for a directed attempt at geoengineering or the "deliberate, large-scale manipulation of the planetary environment" as the U.K.'s Royal Society defines it. Still, scientists are starting to agree that geoengineering will prove insufficient for solving climate change.
To understand this it helps to think of two distinct flavors of climate engineering: those that reduce greenhouse gases and those that block sunlight to keep the planet cool. The various sun-blocking schemes could be fast and cheap, like a fleet of airplanes spewing sulfur particles in the stratosphere to mimic the cooling effects of volcanic eruptions or an armada of ships brightening clouds by increasing the number of water droplets within them. On the other side, carbon removal schemes are slow and expensive, such as big air filters to suck CO2 out of the sky and bury it, turn it into fuel or otherwise keep it from trapping heat. Or the natural processes of rock weathering and plant growth that over geologic time constrain climate change could be sped up. The Intergovernmental Panel on Climate Change in its most recent comprehensive report suggested that one member of...