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
This is a subject close to my heart and over years I have been dismayed that we have failed to reduce our pollution footprint.
Once I got involved in a heated debate about the effect that the introduction of one man operated buses had on increasing urban congestion and exhaust emissions.
I think we came to an agreement that if buses were doing 2.5 million journeys a year (who knows, it might be more or less?) and that on average journey/stopping – starting times had increased by 1 hour (probably more?) then it was equivalent to all buses in UK running their engines continuously for extra 280 years per year .
That is an awful lot of exhaust emissions and does not even account for extra fuel consumption for car users etc.
Perhaps someone who has a little time on their hands can calculate and perhaps re-introduce two man crew buses as cost effective way of meeting targets?
Thanks for this, as heard more briefly on general media, excellent if not just for what it says but “to encourage the others” in active biosphere improvement/reclamation.
Agreed with Graham Powney, and it would also make journeys faster and safer, and encourage more people to use buses outside rush hours. Also bring back electric trolley buses, far simpler than trams (e.g. Nottingham-Ripley throughout WW2 and some twenty years after that).
There is plenty of energy out there to recover CO2 until we get a better energy source, the biggest problem is what to do with it/the product. Turn it back into carbon and burn it again? Pumping the gas underground is short lived and risky.
Here’s another, how to stop the vast underground coal and peat USELESSLY burning & polluting in India and Indonesia?
And, pause for thought, as on Radio 4 lately – “The Great Climate Change Hijack”. Could climate change be diverting attention away from other environmental problems?
BBC investigates if climate change is diverting attention away from other environmental problems such as air pollution, acid oceans and species extinction/excessive human population.
What is the target level of CO2? Is it pre-industrial 280ppm? Is it to hold it at its current 380ppm? Maybe you want to drop it down to 150ppm?
This is a critical and serious question that NO EXPERT HAS ADDRESSED. CO2 levels used to be at 7000 ppm, when animals started roaming Earth 540 million years ago. Nature has been sequestering it underground since then in the form of oil, coal, peat. CO2 generally has been declining 10ppm per million years. On a straight line calculation, nature would have hit the tipping point of 150ppm where nearly all plants on Earth die of starvation in about 10 million years if mankind hadn’t retrieved and started burning carbon based fuels. Thus would have ended Earth’s 3rd atmosphere. At 380ppm, Earth now has about 20 million years before nature sequesters it down to 150ppm.
Environmentalists have presumed mankind has had one of two effects on Earth – either man is bad or neutral. Where is the possibility that mankind’s industrialization may have benefitted Earth?
Graham,
Perhaps a better solution would be to use hybrid buses with a small engine that runs continuously at the optimum speed to charge batteries (irrespective of whether the bus is stopped or not), and electric drive motors for the intermittent motive power. This technology is already about 20 years old, like so many others that people other than engineers are only just beginning to consider….