This article investigates projected changes in temperature and water cycle extremes
at 1.5°C global warming, and highlights the role of land processes and land-use
changes (LUC) for these projections. We provide new comparisons of changes in
climate at 1.5°C vs 2°C based on empirical sampling analyses of transient
simulations vs simulations from the “Half a degree Additional warming, Prognosis
and Projected Impacts” (HAPPI) multi-model experiment. The two approaches yield
overall similar results regarding changes in climate extremes on land, and reveal a
substantial difference in regional extremes occurrence at 1.5°C vs 2°C. Land
processes mediated through soil moisture feedbacks and land-use forcing play a
major role for projected changes in extremes at 1.5°C in most mid-latitude regions,
including densely populated areas in North America, Europe and Asia. This has
important implications for low-emissions scenarios derived from Integrated
Assessment Models (IAMs), which include major LUC in ambitious mitigation
pathways (e.g. associated with increased bioenergy use), but are also shown to
differ in the simulated LUC patterns. Biogeophysical effects from LUC are not
considered in the development of IAM scenarios, but play an important role for
projected regional changes in climate extremes, and are thus of high relevance for
sustainable development pathways.
Revised: February 3, 2021 |
Published: May 13, 2018
Citation
Seneviratne S.I., R. Wartenburger, B. Guillod, A.L. Hirsch, M.A. Vogel, V. Brovkin, and D. Van Vuuren, et al. 2018.Climate extremes, land-climate feedbacks, and land-use forcing at 1.5°C.Philosophical Transactions of the Royal Society A. Mathematical, Physical & Engineering Sciences 376, no. 2119:Article No. 20160450.PNNL-SA-131570.doi:10.1098/rsta.2016.0450