Climate change projected to decrease yields 0-2% per decade; creating up to a 13.2% total decrease b
Without adaptation, temperature increases over 1°C projected to negatively affect major crops’ yields;
Negative impacts on yields become likely after 2030, with projected yield impact 0-2% per decade thereafter. (page 3)
Direct quote: "With or without adaptation, negative impacts on average yields become likely from the 2030s with median yield impacts of 0-2% per decade projected for the rest of the century"
Assuming 2% yield decrease per decade after 2030, total yield decrease by 2100 = 13.2%
100x0.02=2 100-2=98 (by 2040)
98x0.02=1.96 98-1.96=96.04 (by 2050)
96.04x0.02=1.9208 96.04-1.9208=94.1192 (by 2060)
94.1192x0.02=1.882384 94.1192-1.882384=92.236816 (by 2070)
92.236816x0.02=1.84473632 92.236816-1.84473632=90.3920797 (by 2080)
90.3920797x0.02=1.80784159 90.3920797-1.80784159=88.5842381 (by 2090)
88.5842381x0.02=1.77168476 88.5842381-1.77168476=86.8125533 (by 2100)
100-86.8=13.2% decrease in yield by 2100 at 2% decrease per decade after 2030.
Intergovernmental Panel on Climate Change, IPCC Working Group II Contribution to AR5, “Chapter 7: Food Security and Food Production Systems,” in Climate Change 2014: Impacts, Adaptation, and Vulnerability, final draft, released March 31, 2014, 3, accessed May 14, 2014, http://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap7_FGDall.pdf.