The 10:10 campaign was founded by Franny Armstrong, director of the climate change blockbuster The Age of Stupid. The idea came to Franny while walking through Regent’s Park in London on her way to a debate with UK Climate & Energy Secretary Ed Miliband.

Two things sprang to mind: a recent George Monbiot article had laid out the kind of policies we’d need to cut the UK’s emissions very quickly, none of which sounded impossible. And the Climate Safety report had identified a 10% cut in the developed world's emissions by the end of 2010 as the kind of target we should be aiming for to maximise our chances of avoiding a climate catastrophe.

Being an impetuous type, Franny dropped the freshly formed 10:10 idea into that evening’s debate with Miliband, but he barely noticed – though quite a few people from the audience emailed later asking about it.

Soon after, Franny and the Age of Stupid team gathered for a brainstorming session in the countryside. Everyone loved the 10:10 concept as it was simple, catchy, meaningful and something that everyone could get involved in – from businesses and hospitals to schools and families.

Within weeks, the 10:10 idea had rippled out across the nation, picking up support wherever it went. Local authorities, individual, celebrities, faith leaders, economists, universities – virtually everyone who heard the plan wanted to be part of it.

10:10 was formally launched on 1 September, 2009, when it took over Tate Modern’s Turbine Hall (and the whole of the Guardian newpaper's G2 supplement). In those first frantic 72 hours more than 10,000 individuals, businesses, schools and organisations signed up.

• Taking off... A Boeing 747 was an unusual purchase for a climate campaign. But there was (some) method to our madness. Our new acquisition was melted down and turned into fifty thousand 10:10 Tags. Coming soon to a high street near you.

• The unusual suspects... 10:10 was designed to bring new faces into the carbon-cutting fold – and it soon proved to be working. From Spurs FC to Sony UK, the British Embassy in Dubai to Snugburys Ice Cream in Cheshire, the campaign started making sure the climate conversation popped up where you least expect it.

• Energy bills: now with 123% off... To celebrate October 10th (10/10) we teamed up with some heroic partners to give one lucky 10:10er a bells-and-whistles green-home makeover. William in Bristol won the prize, which reduced his energy bills by more than 120%, giving us an amazing case study to show the world what’s possible.

• Taking over Parliament... In late October, the Lib Dems submitted an Opposition Day motion proposing that the entire public sector signs up to 10:10. In 48 hours, 10,000 people contacted their MP urging them to vote in favour. Although we came up a few votes short, the Tories and Lib Dems subsequently made it party policy to cut 10% across the government estate.

• New direction... Eugenie Harvey, the mastermind behind the ‘I’m Not a Plastic Bag’ phenomenon, came on board as Campaign Director late last year and has deftly steered 10:10 from strength to strength through a period of rapid expansion. 

• Going global... The first one arrived just hours into launch day. “Hi, I’m interested in starting a 10:10 campaign here in Malaysia. Can you help?” Before long, we’d had over 100 enquiries from 27 countries. After months of having to respond to this enthusiasm with some polite variant on ‘please hold’, 10:10 Global finally got off the ground in April 2010.

• Ubiquity... On the tabard of an animatronic polar bear at Dublin Zoo. In the UCLH window opposite Warren Street tube. Bolted to the Sage in Gateshead. Around Tamsin Greig’s neck on BBC Breakfast. Pitchside at an FA Cup game. In the windows of 500 car club vehicles nationwide. If you can think of it, the 10:10 logo’s probably been on it.

• Stadium-sized... Polly Holbrook from London became our 50,000th 10:10er, pushing us over the line into Premier League stadium territory. 

• The right kind of public sector cuts... In these tight times, councils love us. Long-suffering sustainability managers tell us that the momentum behind 10:10 has re-energised the carbon-cutting agenda and helped them make the case for more ambitious action. 136 councils have come on board already, which means that over 45% of the UK population now get lower-carbon local services.