If any group wants to not be disenfranchised, then understanding that there's going to be a learning curve for people who have disenfranchised them is important.

I admire Ai Weiwei for his art and his activism. His art is beautiful in form, and in function embodies the principles of populism and social consciousness I aspire to in my own practice.

In the case of the Obama poster, I was just exercising my First Amendment rights - and my free speech is exercised visually. People who want to talk or write in order to share an opinion about Obama can do that, but when I want to say what I think about him, I need to make a portrait.

Street art, of course, is political, because it's illegal, so the very act of doing it is an act of defiance.

After the ignominious collapse of the Copenhagen global climate change summit in 2009, Bolivia organised a People's Summit with 35,000 participants from 140 countries - not just representatives of governments, but also civil society and activists.

China is bearing the environmental cost for much of the world because China is the factory of the world.

Since oceans are the life support system of our planet, regulating the climate, providing most of our oxygen and feeding over a billion people, what's bad for oceans is bad for us - very bad.

Climate neutrality means a situation where the world can naturally absorb the emissions that will continue to be produced in our societies.