After reducing projected emissions by 700 billion tons in 20 years, we have to suck 10 billion tons of year out of the air forever after to avoid 2° C.
The most optimistic scenario says we can hope to remove 5 billion tons of carbon per year by 2050. This is clearly ineffectual.
We can remove up to 5 gtons/year by 2050.
But, we are putting up to 40 gtons/year now.
We will put up 700 billion tons by 2040.
We have to emit 0 gtons/year by 2040 to avoid 2° C.
2° C = Disaster says James Hansen.
Removing 5 gtons/year by 2050 is not enough.
We have to remove at least 10 gtons/year after 2040 every single year to avoid 2° C.
Source: Climate State lecture 25 min. Excellent video. Go to 22:50 for conclusion.