In 2009, Cambridge academic Dr Elizabeth Garnsey and her team published a paper looking at daylight saving hours, electricity demand and what it all meant for carbon emissions. In their study, they found that turning the clocks back each autumn generates an extra 450,000 tonnes of CO2. Dr Garnsey presented her findings to parliament and Climate action group 10:10 launched the Lighter Later initiative, campaigning to shift the clocks forward by one hour throughout the year. In the end, the bill never made it through parliament and we're still rolling with the GMT/BST set up we introduced in 1916.
Lighter evenings lower peak power demand, cutting bills and carbon emissions
The carbon impact of the clock change that Dr Garnsey and her team identified was all to do with when in the day we do things. The study found that daily demand in the UK would be reduced by at least 0.3% if daylight saving time were continued after October. This is because people are generally more active in the early evening than in the early morning, and during winter's dark evenings, we all put the lights on. This creates a peak demand period for energy, which we typically meet using fossil fuel generators. This is both expensive and polluting. In summer time, we don't need to use the lights so much in the evenings, helping us lower energy bills and carbon emissions.
Cutting carbon all year round
While the campaign to keep BST all year round might be stalled, we can all take action to cut carbon throughout the year. Here are our top tips:
BST top tip
When the clocks go forward, remember to nudge your boiler timer too – there's no point in heating up your home at the wrong time. Or better yet, simply turn the heating down.
GMT top tip
Replace old light bulbs with energy-efficient LED replacements. You can swap a traditional 100 Watt bulb for a 14W LED and enjoy the same level of brightness while using ~80% less energy.
William Willet, the British builder who originally proposed BST, had suggested it because he was "incensed" at the wasted daylight hours in summer: "though the sun had been up for hours as he rode his horse... people were still asleep in bed." Perhaps if he was here with us today, he'd be incensed at the wasted opportunity to save carbon, too.