The sun is the source of all energy on planet Earth and we cannot experiment with our only energy source.

We know little of the consequences of the geoengineering process, such as spraying particles into the atmosphere that shade the planet from the sun's rays and could decrease its temperature. But this process is how dinosaurs disappeared from the Earth about 60 million years ago, by particles spewed by a volcano or a giant meteorite impact, and our species could follow suit.

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.

The transformation of capitalism is unstoppable because we need limits on resources for humans to survive.

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.

We are still learning how exactly the Earth reacts to increased CO2 and other greenhouse gases. We know it leads to warming seas which are melting the North and the South Poles, rising and starting to swallow entire coastal areas in the US and elsewhere, as the New York Times article documents.

Trees and clean energy [are] the long-run solution but we have no time to wait for the long run. We need a short-run solution now, and one that encourages and facilitates the transition to the long-run solution.