Forget high-tech, risky climate engineering strategies, such as positioning giant mirrors in space to reduce the amount of sunlight being trapped in the earth’s atmosphere. Cutting back on emissions is the primary way to fight climate change, UCLA-led study finds.
The study is the first scholarly attempt to rank a wide range of approaches to minimising climate change in terms of their feasibility, cost-effectiveness, risk, public acceptance, governability and ethics. The group focused on the most promising five strategies: Reducing emissions, carbon sequestration on land and in the ocean, storing carbon dioxide in a liquefied form, increasing the Earth’s cloud cover, and solar reflection.
Of those approaches, none came close to reducing emissions as much as increased energy efficiency, conservation and low-carbon fuels would. Technology that is already available could reduce the amount of carbon being added to the atmosphere by some 7 gigatons per year, the team found.
“We have the technology, and we know how to do it,” said lead author Daniela Cusack from UCLA. “It’s just that there doesn’t seem to be political support for reducing emissions.”
The next most promising option was sequestering carbon through biological means, including curbing deforestation, promoting growth of new forests and improving soil management, followed by carbon capture and storage, particularly when the technique is used near where fuels are being refined.
Climate engineering approaches that reduce the amount of sunlight heating up the Earth’s atmosphere – such as artificially increasing the earth’s cloud cover or putting reflectors in outer space were – found to be the least viable and their potential impacts not well enough understand.
“Cloud seeding sounds simple,” Cusack said. “But we really don’t understand what would happen to the climate if we started making more clouds.”
Photo credit: Kris Krüg/Creative Commons