Scientists urge caution on climate geo-engineering
The world may need to turn to geo-engineering to tackle climate change effectively, but this would pose enormous challenges, according to academic leaders.
Climate geo-engineering involves deliberate large-scale manipulation of the planetary environment to counteract global warming, but is fraught with all manner of technical, ethical and governance issues.
Techniques include solar radiation management, where sunlight would get deflected by giant mirrors in space, and injecting sulphate particulates into the stratosphere to produce rapid cooling.
However scientists warn these solutions are still embryonic and should at best, be viewed as a complement to and not a substitute for adaption and mitigation.
Oxford University professor of science & civilisation Steve Rayner said that climate geo-engineeering was still at a "very early, imaginary stage" and carried immense technical difficulties.
"To put the sulphate injection idea into action would mean we would have to create an enterprise something on the scale of the global cement industry," he said.
Rayner added that issues of governance and ethics were even more challenging - for example, obtaining international consent, which might require a global treaty. Accountability would also be a crucial issue if anything were to go wrong.
Within the scientific and engineering community there is an overwhelming reticence on the topic, the Professor maintained - even on the idea of doing any research into it.
Speaking to Climate News Network, he said: "Some would prefer not to talk about climate geo-engineering at all. But the general consensus is that on the present trajectory of emissions it's not possible to meet targets limiting global temperature rises."
"We do need research and investigation," he added. "It all needs careful governance - transboundary issues need particularly careful attention."
Rayner is among a team of scientists and academics who have drawn up a set of guiding principles for climate geo-engineering. These include full disclosure, independent assessment of the impacts of such projects, and public participation at each stage of decision-making.