All of us can make changes, but the changes that are most needed are not light bulbs and windows but laws and policies and treaties. So, yes, we are in a phase of this (climate protection) struggle where civic and political action is at the top of the list.

Where solar energy is concerned - and wind energy and battery storage and electric vehicles and efficiency technologies - that is what we are now seeing. So, yes, I'm very optimistic, but anyone who works on the climate crisis has an internal struggle between hope and despair. I won't deny that, but hope has always prevailed in my outlook.

When it comes to climate, we can all make a big difference. At the most basic level, don't let denial go unchallenged and win the conversation on climate.

I think the cost of energy will come down when we make this transition to renewable energy.

I would kiss Tipper much longer.

The conversation on global warming has been stalled because a shrinking group of denialists fly into a rage when it's mentioned.

Take it from me, every vote counts.