Emma Thompson and her daughter in the Arctic with Greenpeace. 08/05/2014 © Nick Cobbing / Greenpeace

Emma Thompson is currently in the Arctic aboard the Greenpeace ship Esperanza. She wrote these words after walking out onto the fragile sea ice for the first time alongside her 14 year old daughter Gaia.

We're told that it is all our fault, global warming — we want the fuel, we want our cars, and that the oil industry is merely responding to the needs of a greedy public. But that's simply not fair. Most of us want to live cleaner lives, but our governments don't make these things easily available.

The changes we need, that the Arctic needs, must come from the top as well as the bottom. We need electric cars to be cheaper and more accessible. We want safer bike lanes in every big city. We want plastic bags to be banned for good. We need governments to stand up to the dirty industries that have for so long funded and controlled them, and to give us all an affordable chance to live our lives in a more sustainable way.

Yes, keep recycling; keep using your own shopping bags, taking transit and using your bike. But also use your voice. Know that you have power and you can make your government listen. Above all, I hope that people stop feeling so guilty and powerless about climate change. That's the lie that keeps us paralysed when really together, we are so much more powerful.

But bear in mind that politicians often lose sight of issues that aren't in front of them all the time. They can end up ignoring even something like climate change, which is possibly the most pressing challenge of our time. So we all need to be bold. Attend a rally, write to your local leaders. If tens of millions of us just wrote to our leaders demanding action on the Arctic and climate change, well – that could change everything.

Please join me, and five million others so far. Visit www.savethearctic.org/emma