the importance of land cover for low emission scenarios · 2017-06-28 · benoit p. guillod,...

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Annette Hirsch C2SM GCM User Workshop

27.06.2017 1

The importance of land cover for low emission scenarios

Annette L. Hirsch

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Possible Futures within the RCPs

Annette L. Hirsch

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HAPPI: Half a degree Additional warming, Prognosis and Projected Impacts

Source: Mitchell et al., GMD 2016


Implicit assumptions in the RCPs

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Low emission scenarios assume large scale changes in land use

Annette L. Hirsch

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How does land use influence the impacts of different low emission scenarios?

Annette L. Hirsch

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Experimental Design

Source: Mitchell et al., GMD 2016

1.5˚C Target

2.0˚C Target

27.06.2017 Annette L. Hirsch 7

CESM v. 1.0.4

Atmosphere CAM4

Land CLM4 • CN Mode

Prescribed SSTs and Sea Ice

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SSPs: Shared Socioeconomic Pathways

Annette L. Hirsch

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land use compatible with low emission scenarios

Figures for: “Land use in low climate warming targets critical for hot

extreme projections”

Benoit P. Guillod, Annette L. Hirsch,Jonathan Doelman, Lena Boysen, Viktor Brovkin, Detlef Van Vuuren, Sonia I. Seneviratne

(order to be determined)

June 19, 2017

Figure 1: Changes in the three main land use categories for the three land use scenarios, expressed as the di↵erencebetween years 2095 and 2010. The land use scenarios are: (top) RCP 2.6 from CMIP5, (center) SSP1 for RCP1.9from IMAGE, and (bottom) SSP2 for RCP1.9 from IMAGE.

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Annette L. Hirsch


∆TXx (with minus without LUC) [˚C]

Figure 2: Change in annual maximum daytime temperature (TXx): Land use change e↵ect for all land use scenarios,expressed as the di↵erence with the respective future scenario (1.5 or 2 degrees) without land use change. (left)1.5 degree, (right) 2 degrees. Land use scenarios, from top to bottom: (1st row) LU26, (2nd row) SSP1, (bottomrow) SSP2. Stippling indicates where the ensemble mean TXx significantly di↵er according to bootstrap samples (seeMethods).

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Ratio LU Forcing to All Forcing

Figure 3: As Fig. ?? but with divided by the total TXx changes (respective scenario minus present-day simulation).Absolute values of the ratio are displayed. Stippling is as on Fig. ?? and indicates where the ensemble mean TXxsignificantly di↵er according to bootstrap samples (see Methods)

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∆TXx (2.0 minus 1.5) [˚C]

Figure 4: TXx: (a) Di↵erence between a 1.5 and a 2 degree warmer world (2 minus 1.5) with di↵erent land useassumed for each climate target. Rows refer to land use scenarios for the 2 degrees simulations, columns to the landuse scenarios for 1.5 degree simulations. Hatching indicates statistically non-significant di↵erence between both climatetargets. (b) For regionally-averaged TXx, distribution of anomalies in individual ensemble members relative to theensemble mean of Hist.

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Land use HIST LU26 SSP1 SSP2

Figure 4: TXx: (a) Di↵erence between a 1.5 and a 2 degree warmer world (2 minus 1.5) with di↵erent land useassumed for each climate target. Rows refer to land use scenarios for the 2 degrees simulations, columns to the landuse scenarios for 1.5 degree simulations. Hatching indicates statistically non-significant di↵erence between both climatetargets. (b) For regionally-averaged TXx, distribution of anomalies in individual ensemble members relative to theensemble mean of Hist.

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Central Europe

Central N. America

East Asia East N. America

North-East Brazil


Land Use Matters!

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Now have other model groups on board!

Annette L. Hirsch

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ETH: B. P. Guillod, S. I. Seneviratne and U. Beyerle

MPI: L. Boysen and V. Brovkin,

PBL Netherlands: J. C. Doelman, E. Stehfest and D. van Vuuren

U. Tokyo: H. Kim and T. Nitta

NIES Japan: H. Shiogama

U. Bristol: D. Mitchell

CPDN Oxford: S. Sparrow

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Thank you!

Annette L. Hirsch

the importance of land cover for low emission scenarios · 2017-06-28 · benoit p. guillod,...

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