What would your world look like if it were devastated by climate change? In the small, impoverished community of Gabura in Bangladesh, the concept of global warming, often only words on a screen or in a newspaper to us, is an all too bleak reality. The inhabitants face danger from rising sea levels, devastation of crops and the increased likelihood of devastating cyclones.

Oxfam's remarkable new online interactive documentary – Gabura, from daily life to disaster - launched in conjunction with the Guardian yesterday, allows you both to bear witness to the impact of climate change and to choose your own journey through the story.

We enable you to see vividly how livelihoods have been ruined, crops destroyed, and families torn apart. To step into their shoes, and see where they go, how they live, and the hardships they suffer from the impact of climate change.

Why have we chosen this medium to talk about climate change? Because, ahead of crucial talks this December in Copenhagen, we need our message to get out there in as many different ways as possible.

We wanted to show some of the many stories about the devastating impact of climate change. After all, it is the people in poorer communities whose voices are all too often drowned out in the drumbeat of reports, debates and summits.

There is Abdus, a farmer whose crops were lost after a bad harvest, who fears he cannot feed his family. There is Hosne Ara Khatun, a young widow too traumatised to speak after her husband was mauled to death by a tiger, starved as its natural habitat has disappeared due to rising sea levels. And there is the young father left to weep over the loss of his wife and young children after the community of Gabura was lashed by the devastation of cyclone Aila.

They may seem thousands of miles away, but their troubles are real, they are growing worse, and they could soon happen to us unless we take action now.

So while we show you – and allow you to choose – the images of devastation caused by climate change, we are also letting you know what you can do to stop the damage.

The UK is currently preparing for its biggest ever climate change demonstration in support of action against climate change, The Wave, on 5 December in London.

The march is one of scores of events by Oxfam and its partners ahead of the talks in Copenhagen, as we urge world leaders to forge a safe and fair climate deal to halt dangerous global warming and protect those most at risk, such as those living in Gabura.

By calling on our leaders to act on climate change this December, we help the people of Gabura, and we help ourselves.

• Barbara Stocking is the chief executive of Oxfam