Soil Carbon Response to Climate Warming - Using Functional Benchmarks to Evaluate Model Projections of Soil Carbon Dynamics in a Changing World
Abstract
Climate is changing, with some of the fastest rates of warming observed in the high northern latitudes. Warming temperatures could benefit plants (increase productivity, accelerate nutrient cycling, extend the growing season). However, climate warming could also lead to greater soil carbon losses through permafrost thaw and increased rates of microbial decomposition. Given the size of global soil carbon stocks, and the vulnerability of these stocks to changing climate conditions, particularly at high latitudes, it is critical that models accurately simulate soil carbon dynamics under a range of possible future climate conditions. However, current global scale models project that as the climate warms, carbon losses from soils could range from minimal to significant. This uncertainty arises from several factors, including the lack of data with which to robustly benchmark global-scale models. A key challenge is confronting models with observations that not only tell us whether models produce the right endpoints (e.g., total soil C), but the correct pathway(s) to those endpoints (e.g., response of soil respiration to warming). In this talk, we leverage the sensitivity simulations of the Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP) and a tiered benchmarking approach that evaluates modeled functional relationships and emergent properties related to changing temperature conditions. Specifically, we test whether models accurately simulate the relationship between transient soil carbon dynamics and temperature across a range of temperature values. These "functional benchmarks" have the ability to provide better insight into the potential predictive power of models. We also evaluate the information content of current observations and highlight key observational needs to better guide model development and, ultimately, reduce uncertainty in projections.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.B51A..10H
- Keywords:
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- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCESDE: 0428 Carbon cycling;
- BIOGEOSCIENCESDE: 0465 Microbiology: ecology;
- physiology and genomics;
- BIOGEOSCIENCESDE: 1622 Earth system modeling;
- GLOBAL CHANGE