In a lecture to be delivered today at the British Science Festival, one of Britain’s most senior scientists the astronomer royal Lord Rees suggests that experimental “Plan B” schemes such as launching mirrors into space, triggering algal blooms in the oceans and seeding clouds, should start to be considered in response to global climate change from rising carbon emissions.
Fairly controversially, Lord Rees suggests that manipulating the planet’s climate through geoengineering, which he admits would be “an utter political nightmare”, would buy time in our quest for development of cleaner sources of energy. Geoengineering refers to deliberate interference of the planet’s natural systems to counteract climate change through global warming.
Some of the techniques that Lord Rees, a former president of the Royal Society and a cosmologist at Cambridge University, suggests include placing mirrors into the mesosphere to reflect sunlight before it enters the Earth’s atmosphere, and artificially fertilising the world’s oceans with iron to encourage algal blooms that can absorb atmospheric carbon dioxide.
However, inspired by the 1991 eruption of Mt. Pinatubo in the Phillipines that saw global temperature drop by 0.5C, Lord Rees’ preferred option would be to send particle dust into the stratosphere to form clouds which would reflect some of the Sun’s energy back into space.
The concept of geoengineering will remain controversial, and I imagine highly debated. Although we may be able to model the direct and indirect effects of these processes, due to the highly unpredictable and chaotic nature of climate the true effects of geoengineering will be hard to predict. It’s certainly an interesting, exciting and daunting period to be involved in climate change science.