As efforts to reduce greenhouse gas emissions fall woefully short and many scientists agree cuts alone will not be enough to avert the consequences of climate change, radical new schemes are being proposed.
Once considered far-fetched or even dangerous, ideas to engineer the climate have migrated from the margins of policy debate toward the center.
While “Plan A” remains tackling the problem at its source, these “Plan Bs” include a raft of so-called geoengineering solutions.
One of those is a controversial idea known as stratospheric aerosol injection. The idea basically involves spraying a bunch of aerosols into the stratosphere so the reflective particles block and reflect the sun’s rays, ultimately cooling the planet.
This already happens naturally through volcanic eruptions, but some scientists believe a controlled and targeted release of certain aerosols could be the way to go.
“For example, just 2.2 pounds of sulfur well placed in the stratosphere would roughly offset the warming effect of several hundred thousand pounds of carbon dioxide,” wrote researchers in a 2009 report entitled “The Geoengineering Option: A Last Resort Against Global Warming?”
However, while blasting aerosols into the sky and other similar ideas are advocated by some, a new study published this week in the journal Nature Ecology & Evolution has added to doubts about the plan.
“The potential biodiversity consequences are largely unknown,” researchers wrote.
They used models to predict what would happen if we sprayed the sun-blocking aerosols for 50 years and then abruptly stopped. What they determined is that once we eventually ceased, heat-trapping greenhouse gases, which are still being pumped into the atmosphere, would then speed up the warming of the planet at a much more accelerated rate. Ultimately, they concluded, temperatures would likely rise too quickly to give animals time to adapt or move to more comfortable environments, leading to a huge loss in species.
“Compared to a moderate climate change scenario, rapid geoengineering implementation reduces temperature velocities towards zero in terrestrial biodiversity hotspots. In contrast, sudden termination increases both ocean and land temperature velocities to unprecedented speeds,” they said.
“Rapid geoengineering termination would significantly increase the threats to biodiversity from climate change.”
The effects would be two to four times worse than with global warming alone, the study said.