Given the changes observed over the last half century, it is evident that every 0.5°C of global mean surface temperature warming has profound implications for ecosystems (e.g. Tape et al., 2016). What are the expected changes in biodiversity, material cycling and ecosystem services under full implementation of the Paris Climate Agreement? The 2015 UNFCCC Paris Agreement intends to hold ‘the increase in the global mean surface temperature (GMST) to well below 2°C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5°C.’ (UNFCCC 2015). What are the critical thresholds that might be crossed at 1.5°C, 2°C, or at a higher temperature under current nationally determined contributions for emissions reductions? Studies suggest that limiting global warming to 2°C is unlikely to save most coral reefs (Frieler et al., 2012). How does decreasing days of snow cover in seasonally snow-covered regions influence species migrations? Where are the highest risk limits (e.g. montane elevation) to habitable ranges for at risk species? Which natural processes such as drought or fire become so severe or extensive in a warming world that ecosystem disruptions occur? Which are the critical ecosystems most at risk of being completely transformed if the Paris Climate Agreement is not implemented? Which ecosystems are likely to be most resilient? ESA 2017 can spur submissions of publications to be included in the second order draft of the IPCC Special Report on 1.5°C (https://www.ipcc.ch/report/sr15/).