Cumulative Impacts of Human-Induced Changes on Carbon Cycle Extremes

Carbon cycle extremes are examined from 1850-2300 with the CESM1-BGC earth system model to understand the longer-term cumulative impacts of global warming and land use change beyond the standard projection horizons of 2100 reported in the literature. Simulations are considered with and without land use and land cover change (LULCC) and across representative concentration pathways to understand the possible human impacts. Nonlinear relations and feedback between climate drivers and carbon cycle extremes are examined. Our preliminary results suggest that the intensity, frequency, and duration of carbon cycle extremes may be higher for negative extremes compared to positive extremes, while both the type of extremes increases when land use and land cover changes are considered. This line of work has the potential to provide new insights into the contribution of human activities in altering carbon cycle extremes, quantify the implications for terrestrial carbon budgets, and inform future mitigation and adaptation policies.