First:
NYTimes
My total turnaround, in such a short time, is the result of careful and objective analysis by the Berkeley Earth Surface Temperature project, which I founded with my daughter Elizabeth. Our results show that the average temperature of the earth’s land has risen by two and a half degrees Fahrenheit over the past 250 years, including an increase of one and a half degrees over the most recent 50 years. Moreover, it appears likely that essentially all of this increase results from the human emission of greenhouse gases.
Larger than the .8 deg C McKibben figure.
Next:
Copenhagen_Diagnosis_Fig_21
Source (PDF):
Copenhagen_Diagnosis
Slope of the line from 2000-2100 = .06 deg C/yr
Time to +2.0 deg C (from 1.4 now) ~ 10 years.
Which at 2 ppm CO2/yr will put us at ~ 420 ppm.
2022 is the cliff's edge.