There is always a tendency to overestimate how fast change will occur and extrapolate into the future in simplistic ways but many of those who see the singularity coming think it could be fast, they even date it about 2040s - this is because of the doubling effects of exponential change which reaches take off (the elbow on the curve) in the 2030's. For an interesting but US centric take on this see the last chapter of War; What is it good for, Ian Morris - the job is for the US, the current US 'Globocop' to hang on in there until Pax Technologica replaces Pax Americana (2014 pre Trump) - Bibliography
If climate change hits a tipping point it could trigger big changes very quickly in the next 20-30 years, see James Lovelock, The Revenge of Gaia - Bibliography
Part 2 Assess - Timeline - Future - Possible Futures