That our planet will see less than 400ppm CO2 in the atmosphere within the lifetime of anyone currently alive.
From 2017 onwards, that level will always be over 400ppm. That is a full 120ppm higher than the peak interglacials in the last few million years. It will continue to rise at approximately 2-2.5ppm per year for at least the next 15 years as the plan, now that pegging with the 1990 levels has failed miserably, will only lower emissions to around 1.5-2ppm per year. Which is a far cry from reduction.
Whatever happens now, unless we take a stance which reduces our emissions to 0 in the next two decades, our descendents will be dealing with a world which has 2* the interglacial CO2 of the last few million years.
Sobering thought... They guys at 350.org must be despondent.