Assessing Hydroclimatological Sensitivity to Climate Change Across Northern Eurasia

By understanding the spatial variability of areas at high latitudes that are most sensitive to climate change, we can begin to focus on those regions in which the human populations will be more or less vulnerable to change. Using multiple variables to describe the human-biophysical system combined together, we get a single snapshot of the “hot spots” of sensitivity. We used a broad-scale index approach, adapted from the Giorgi (2006) Regional Climate Change Index (RCCI), using temperature and precipitation data from the IPCC AR4 simulation runs for the pan-Arctic drainage region of Eurasia gridded to Northern Hemisphere EASE grids. The adapted index, or Arctic Climate Change Index (ACCI), considers the change between 1960-1999 and 2080-2099 for four variables: surface air temperature, precipitation, temperature interannual variability, and precipitation interannual variability. An ACCI value layer was calculated independently for eight CMIP3 models and two IPCC emissions scenarios. To provide a measure of certainty/uncertainty in the region’s responsiveness to climate change, standard deviation was calculated across the 16 subsequent ACCI layers. The ACCI identified several areas of high and low sensitivity to climate change. Areas of high sensitivity tended to have higher certainty levels across the broad range of future climate predictions. Applying the regional sensitivity and certainty measures to the human population, we found the areas of the Eurasian pan-Arctic that are most sensitive to future climate change are also areas having less uncertainty and with greater population. This indicates that a large portion of the population in pan-Arctic Eurasia has relatively greater vulnerability to projected future climate change.