What is the fine-grained topic of the following text: ABSTRACT: Using an optimal fingerprinting method and the Coupled Model Intercomparison Project Phase 5 (CMIP5) multi-model simulations, we attempted to quantify the human contribution to the observed annual mean temperature change that occurred over China between 1961 and 2005. Only return the topic.
Quantifying human contribution to annual mean temperature change in China from 1961 to 2005 using optimal fingerprinting method and CMIP5 simulations.