A mismatch between model- and proxy-based Holocene climate change may partially originate from the poor spatial coverage of climate reconstructions. Here we investigate quantitative reconstructions of mean annual temperature and annual precipitation from 1908 pollen records in the Northern Hemisphere. Trends show strong latitudinal patterns and differ between (sub-)continents. Our work contributes to a better understanding of the global mean.

Climate reconstruction from proxy data can help evaluate climate models. We present pollen-based reconstructions of mean July temperature, mean annual temperature, and annual precipitation from 2594 pollen records from the Northern Hemisphere, using three reconstruction methods (WA-PLS, WA-PLS_tailored, and MAT). Since no global or hemispheric synthesis of quantitative precipitation changes are available for the Holocene so far, this dataset will be of great value to the geoscientific community.

The sensitivity of climate to the height changes of the East Antarctic ice sheet (EAIS) during the mid-Pliocene has been assessed using the HadCM3 model. The results show that the height reduction of the EAIS leads to a warmer and wetter East Antarctica. However, unintuitively, both the surface air temperature and the sea surface temperature decrease over the rest of the globe. These findings could provide insights into future changes caused by warming-induced decay of the Antarctic ice sheet.

Stratospheric aerosol intervention geoengineering is considered a potential means to counteract global warming. Here the impact of stratospheric aerosol intervention geoengineering on surface air temperature over China and related physical processes are investigated. Results show that the increased stratospheric aerosols cause surface cooling over China. The temperature responses vary with models, regions, and seasons and are largely related to net surface shortwave radiation changes.

We present an experimental design for a new set of transient experiments for the Holocene from 11.5 ka to the preindustrial period (1850) with a relatively high-resolution Earth system model. Model boundary conditions include time-varying full and single forcing of orbital parameters, greenhouse gases, and ice sheets. The simulations will help to study the mean climate trend and abrupt climate changes through the Holocene in response to both full and single external forcings.