Busy Londoners get wrapped up in the here and now: train delays; work deadlines; bad weather. Our idea was to use powerful images to show them that, while they were moaning about the drizzle on their commute, rain was having altogether more serious consequences in Bangladesh.

Another campaign featuring pictures of people on rafts or flood-damaged communities wasn't going to cut it. People have grown immune to images of people in need, however hard-hitting.

To get Londoners to not only notice, but care enough to leave their warm homes on a cold winter day to join a climate march, we needed symbolic imagery that would imply heart-breaking stories; all the more powerful in the imagination.

We identified a renowned humanitarian and environmental photojournalist to capture the images. His work in war-torn and weather-ravaged countries meant that he has seen first-hand the devastating effects of climate change and flooding.

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.

Outcomes/awareness:

The campaign resulted in the largest ActionAid presence at a public demonstration since Make Poverty History in 2005. We’d moved Londoners not just to share or donate, but to contribute their time. Over 300 people marched with ActionAid at the People’s Climate March. On the back of the campaign, ActionAid spokesperson Himaya Quasem gave the opening speech at the march to more than 50,000 people.

As the world’s leaders converged on Paris for COP21, we gave ActionAid a credible voice in the climate change debate:

Knowledge/consideration:

282 pieces of coverage, including the Daily Mail and interviews on BBC Asian Network and London Live. Most featured the YouGov poll and ActionAid messages. Rain triggered the advertisement six times during the week, with run time of 2hrs.

Outputs/business results:

• Facebook reach: 30,965

• Twitter impressions: 1,111,922

• Total engagement: 12,835

• Blogs: 1,100 views

• Landing page: 2,563 views

• Total reach: 343 million (400,000 target).