We have used the majority of our carbon budget and we are already at dangerous levels of CO2 concentrations, about 400 parts per million. The levels were 250 before industrialization. So the problem is what we have done already and, therefore, what must be undone.

The first reaction to trauma is denial, then comes anger and finally, acceptance. I think the US is still between denial and anger, and I hope we will reach acceptance because almost perversely, right now, only the US has the technology that is needed for global economic change.

Signs of a poorly understood but treatable house fire requires action, not inaction.

The change in economic values created by the new markets for global public goods will reorient our global economy and under the right conditions can usher the satisfaction of basic needs of the present and of the future. This is what is needed right now.

To survive, humans need food, water, and air. Yet biodiversity, the Earth's bodies of water, and the planet's atmosphere are all under threat.

Geoengineering means changing the Earth's fundamental large-scale processes.

Trying to conserve a privileged global position makes change traumatic for the US.