Katja Frieler, Bernhard Schauberger, Almut Arneth, Juraj Balkovic, James Chryssanthacopoulos, Del- phine Deryng, Joshua Elliott, Christian Folberth, Nikolai Khabarov, Christoph Müller, Stefan Olin, Thomas Pugh, Sibyll Schaphoff, Jacob Schewe, Erwin Schmid, Lila Warszawski, and Anders Levermann. Understanding the weather-signal in national crop-yield variability. Accepted for publication in Earth Systems Dynamics, 2017.