Shady stories

The environment, and climate change in particular, is still a political hot potato. While the main thrust of technology and policy is in reducing emissions and finding ways to use less energy to run industry and our domestic power-guzzling, there is also a small, but growing, interest in what’s known as geoengineering. This is the application of technology to directly reduce global warming, either by sucking greenhouse gases out of the atmosphere, or by limiting the amount of solar radiation hitting the Earth’s surface.

For many technologists and politicians, this is pie-in-the-sky stuff; unproven technology with an uncertain outcome and side effects that are impossible to predict. For others, it’s downright immoral, giving polluters a green light to continue polluting: why go to all that trouble and cost to reduce emissions, when some handy gadget is going to hoover it down again?

But there are arguments for it as well, and researchers this week presented some of their ideas in a report from the Institution of Mechanical Engineers; 100,000 artificial trees around the UK to remove CO₂ from the atmosphere, ready for compression and storage; algae-filled bioreactors on buildings, capturing CO₂ by biosynthesis; and reflective roofs, sending incident light back into the sky and keeping the cities cool.

Tim Fox, lead author of the report, insists that without geoengineering, there is no chance of avoiding climate change, but that it should only be regarded as a way to buy some time while emissions reduction and energy efficiency measures are built up. And his report doesn’t mention some of the more outlandish ideas for cooling system, such as a constellation of space sunshields reducing the amount of light that hits the upper atmosphere, or ships spewing out highly reflective clouds.

As a glimpse into the future, this is a difficult one to call. Geoengineering would be a tricky but striking political statement — no government could be accused of taking climate change lightly if they launched this type of highly-visible effort, especially if it were additional to, rather than instead of, emissions reduction-based programmes. But it’s also hugely risky.

If the engineers working on these technologies can crack the uncertainties around them, however, it becomes a slightly different argument. As one geoengineer said to The Engineer recently: ‘If you can do it, then why on Earth wouldn’t you?’

Stuart Nathan
Special Projects Editor