Recent trends in the near-surface climatology of the northern North American Great Plains

Precipitation P increased in the eastern portion of the NNAGP during all seasons except fall and increased during May and June in excess of 8 mm decade(-1). Climate trends in the NNAGP largely followed global trends except during the early warm season (May and June) during which 2-m air temperature T-air became cooler, VPD lower, and P greater across large parts of the study region. These changes are consistent with observed agricultural intensification during the study period, namely the reduction of summer fallow and expansion of agricultural land use.

Global climate model simulations indicate that observed T-air trends cannot be explained by natural climate variability. However, further climate attribution experiments are necessary to understand if observed changes are caused by increased agricultural intensity or other factors.