Park your grand plans. It’s the simple ideas that work best

Painting the world's roofs white might seem foolish but, given what scientists are about to do, it's starting to look sensible. UK researchers will soon embark on trials of a technology designed to save us from ourselves - and it involves pointing a kilometre-long hosepipe into the sky.

The idea is to experiment with pumping water (and eventually sulphates) into the atmosphere. Due to their tiny particle size, sulphates will stay aloft and their reflective properties should keep sunlight away from earth.

So reluctant have we been to curb our carbon emissions that some reckon there's a 50:50 chance that we'll have to resort to such "geoengineering" of earth and its atmosphere. Other grand gestures might involve sprinkling iron filings on the ocean to create a boom in carbon-guzzling plankton, or spraying seawater into clouds to make them whiter and more reflective of sunlight. Another "solution" is out of this world: using space-based mirrors to reflect away some of the sun's radiation before it enters the atmosphere.

According to one researcher, we must explore geoengineering because it is likely "it'll get too warm and people will demand the planet be cooled off". Probably best to come clean - science rarely delivers solutions on that scale.

You know that nuclear fusion project which started after the Second World War and was just 40 years away from generating limitless energy? More than half a century later, the power is still 40 years away. Hoping you can mitigate climate-change effects with a planet-size sulphate sunshade? That, history tells us, is not a sensible outlook.

Mini wonders

What science does best is slow, small-scale improvements. We use videophones as routinely as people used to in sci-fi movies. Remember when car exhausts spewed out blue, choking fumes? Of course you don't - but when was the last time you showed your appreciation for the catalytic converter?

Efficiency improvements must play a large, if unsexy, part of meeting future energy demands. You can look to nuclear initiatives, but the plants being built in France and Finland are billions of pounds over budget and construction is years behind schedule. Loft and cavity wall insulation in UK housing, coupled with smart meters that control and co-ordinate our energy demands, offer a much safer investment.

So the best way to turn the thermostat down on earth might be as dull as painting our roofs and roads with light-coloured paint. According to the US energy secretary, Steven Chu, it could have the same effect as taking every car in the world off the road for 11 years.

Let's save the dramatic interventions for the cinema and allow scientists to focus on solutions that will work.