We shouldn't have stupid cars that use liquid fossil fuels. Come on, how outmoded is that? We have to get to the point where this is no longer a part of our experience.

The fact that solar has gone down 80 percent since 2008 is astonishing. Wind is perhaps not coming down as quickly. Lack of storage - batteries - is a bottleneck. That makes it very difficult to put large amounts of renewable energy on the grid.

Connect with people, visibly and loudly showcase initiatives that reduce greenhouse gases emissions, nurture youth leaders, or spread the message by raising awareness through campaigns. I am convinced that your contributions will ensure that climate change solutions safely power our - and especially your - future.

Each building should produce as least as much energy as it's going to need, and have more to put on the grid. They should be using all of the natural light and natural heat.

I still do not understand why we don't have people on the streets every single day raising their voices for climate.

In a perfect world global emissions would have peaked already. In a semi-perfect world we will peak on Dec. 31, 2020. The fact is, that's going to be difficult. We know that it's going to get more and more expensive the longer we delay.

This is probably the most difficult task we have ever given ourselves, which is to intentionally transform the economic development model, for the first time in human history.