Fifty children drown in Bangladesh every day. Waters are rising, and floods, cyclones and storms are getting bigger and coming faster.

ActionAid needed to raise awareness of the devastating effect of floods and climate change on children, families and communities in Bangladesh.

ActionAid is not an environmental organisation: it is a development charity, working with vulnerable women and girls to find lasting solutions to poverty. But its first-hand experience meant that, for the first time, it needed to make its voice heard in the climate change debate.

In the run-up to the crucial COP21 talks in Paris, our objective was to create a campaign that would break through Londoners’ apathy. We wanted to motivate 200 people to take action and attend the People’s Climate March in London with ActionAid on 29 November.

We worked with a renowned environmental and humanitarian photojournalist Antonio Olmos to create the campaign images. Based on first-hand experiences in Bangladesh, he painstakingly recreated powerful images of children’s toys washed up in the aftermath of a flood, using authentic toys, silt, foliage and debris.

Using the images, we created a weather-activated advert for a digital billboard in London’s iconic Piccadilly Circus – the most iconic advertising space in Europe, with weekly footfall of two million.

An algorithm was custom-coded to analyse real-time local data from a nearby electromagnetic sensor operated by the Met Office, the government weather forecaster. In the week before the march, rainfall in London triggered the ad, disrupting the schedule.

Owned/paid Facebook and Twitter posts featured the campaign. We pitched YouGov survey results, showing 38% of Brits were more worried about climate change than five years ago, especially the impact on developing countries, to the media.