New experiments with RCP8.5 and RCP6.0 added

As decided at the ISIMIP Strategy Group Meeting, we added two new experiments, VIII and IX, to all sectors. Exp. VIII is driven by RCP8.5 climate input data to analyze high-end impacts, while the optional exp. IX uses RCP6.0 climate input data that were bias-adjusted and statistically downscaled with an improved method that shall be used in ISIMIP3b. Comparing exp. III and IX allows us to assess the sensitivity to using the ISIMIP2b method versus the ISIMIP3b method for bias adjustment and statistical downscaling.
The scenario-design figures were adapted accordingly.