I have just witnessed, along with millions of others around the world, the swearing in of President Barack Obama of the United States of America. I was going to be on the Mall just left of the Washington Monument (had the jumbotron screen all scoped out after the concert on Sunday), and was all ready to go, when, as life would have it, my 11 year old son woke up with a horrible cold and fever. Standing in the freezing cold for 6-7 hours was just not on the cards for today, so we said farewell to the other half of the family and settled down in front of our minitron (tv).

We watched along with everyone else around the world, and tears streamed down my face at the thought of this great man, an African, just like me, taking on the mantle of one of the greatest offices in the world. Our stories are a bit different (ok, a lot different), but I like to think that somewhere there are some parallels. Obama grew up a black African in the white world of the United States. I grew up a white African in the confused and oppressed country of South Africa – what should have been a black world.

At a certain point in my life, there was an awakening as to what the wrongs of that world were, what needed to be righted and what I needed to do to participate in making those changes happen. Clearly, for Obama, a similar process took place. Now, it might seem odd to compare my small life with that of the new US President, but I think that part of why we are all so moved by what is going on in Washington today is because in some small way, each of us can identify with the story unfolding here, the hope it embodies, the spirit it causes to soar.

And I can only hope that President Obama’s first trip abroad is to meet with Nelson Mandela, the man whose moral courage through adversity led a people to freedom; and in so doing, Obama could emulate the strength, humility and commitment of this great man. What a privilege to have been witness to two great moments in history: the freedom of Mandela and the South African people; the inauguration of Obama, and maybe, just maybe the freedom of the people of the United States of America and everyone who believes in change and hopes for peace across the world.

I keep thinking that I should now take a reality check, acknowledge that this moment will not last and come tomorrow, we will be back to bringing truth to power, taking on the forces who continue to press for the status quo at a time when sticking to the status quo is the radical thing to do; where embracing change for the future is common sense.

And I know that this little bubble will burst and we at Greenpeace will press on with peaceful confrontation to achieve the changes our planet and our children so desperately need to see happen. As one of our political team, I also know we have a crazy political year ahead of us – a year that will in many ways determine the future for generations to come and the health and well-being of our planet. We are bombarded with the knowledge that our failure to change our ways is crushing the future potential that our planet holds. Unfettered economic growth, selfishness, inequity, poverty, and the security of all peoples and creatures on our earth are under threat. Yet there is an opportunity for the leaders of the world to follow the wishes of their peoples and to forcefully address the biggest challenges to our future: global climate change.

In the United States and in South Africa before it, change was driven by the actions and votes of individuals inspired to work for it. So too, if there is any lesson from today, it is that each of us needs to stand up, make ourselves heard and act over the course of the next 12 months to inspire our leaders to change, to work for future generations, and to agree to a global climate deal in Copenhagen in December that will ensure all of our peace and security for the next century.

Karen Sack is a Political Advisor at Greenpeace International