Figure 1, Schellnhuber et al (2016): Tipping elements in context of the global mean temperature evolution. Shown is the global mean surface temperature evolution from the Last Glacial maximum through the Holocene, based on palaeoclimatic proxy data (light grey), instrumental measurements since 1750 AD (HadCRUT data, black line) and different global warming scenarios for the future. Threshold ranges for crossing various tipping points where major subsystems of the climate system are destabilized have been added. (Note that we follow the tipping point definition of Lenton et al. which does not require irreversibility, so that sea ice cover is included here.) The range for the Western Antarctic Ice Sheet (WAIS) has been adapted to account for the observation that part of it has probably tipped already. THC, thermohaline circulation; ENSO, El Niño-Southern Oscillation; EAIS, Eastern Antarctic Ice Sheet.
For references, see the paper: Schellnhuber, H.J., Rahmstorf, S., Winkelmann, R. (2016): Why the right climate target was agreed in Paris. Nature Climate Change