Rate and velocity of climate change caused by cumulative carbon emissions

摘要: International climate mitigation efforts are focused on limiting increase in global mean temperature, which has been shown to be proportional cumulative CO2 emissions. However, the ability of natural and human systems successfully adapt climatic changes depends both magnitude rate change, latter will depend how quickly a given level emissions occurs. We show that 4620 Gt (reached 2100 RCP4.5 2057 RCP8.5) produce globally averaged warming rates nearly twice as fast RCP8.5 than (0.34 ± 0.08 °C per decade versus 0.19 0.05 decade, respectively). Similarly, velocity change calculated according 'nearest equivalent climate' is greater by factor ~2 (2.51 0.67 km yr−1 1.32 0.39 yr−1, respectively), despite These differences projected represent uncertainty for ecosystems may unable faster changes. Particularly at risk boreal forests, 48% experience beyond their expected adaptive capacity (i.e. >0.3 decade) RCP4.5, compared with 95% RCP8.5. Thus, same budget carbon result critically different impacts systems, depending amount time over expended.