Tim Mainwaring, Memetician, University of Toronto. “This decade is critical for the climate. Our last chance to prevent our children from a hellish future will be 2019, 2020, 2021. Three critical years. By either 2020, 2021 or 2022 we will have sealed our future trajectory. Certainly 2023. If we get there. We will know if we get to 2023 by 2019.”