We're putting 70 million tonnes of pollution into the atmosphere every day, trapping an enormous amount of extra heat from the sun inside the earth's atmosphere. It's threatening to push the planet past a tipping point beyond which climate change would be difficult to stop

The consensus is clear. We need an immediate and determined shift to a clean, renewable economy. The continued mass burning of fossil fuels is inconsistent with a healthy, prosperous future for our civilization.

We need to put a price on carbon. This needs to be a priority for all of us in how we vote.

What's at risk [in 100 years] if we do not take action, truly is the survival of civilization as we know it... Literally that is the case. We have seen global warming so far of just a little bit less than one degree Celsius and look at what's happened. Superstorm Sandy. Boulder Colorado. All these fires. Hurricane Irene one year before.

The physical relationship between CO2 molecules and the atmosphere and the trapping of heat is as well-established as gravity, for God's sakes. It's not some mystery.

The struggle to save the global environment is in one way much more difficult than the struggle to vanquish Hitler, for this time the war is with ourselves. We are the enemy, just as we have only ourselves as allies.

Science has a culture that is inherently cautious and that is normally not a bad thing. You could even say conservative, because of the peer review process and because the scientific method prizes uncertainty and penalises anyone who goes out on any sort of a limb that is not held in place by abundant and well-documented evidence.