Impact references

test{{Harvnb|IPCC SR15 Ch2|2018}} {{cite book |ref={{harvid|IPCC SR15 Ch2|2018}} |year=2018 |chapter=Chapter 2: Mitigation Pathways Compatible with 1.5°C in the Context of Sustainable Development |chapter-url=https://www.ipcc.ch/site/assets/uploads/sites/2/2019/05/SR15_Chapter2_High_Res.pdf |display-authors=4 |first1=J. |last1=Rogelj |first2=D. |last2=Shindell |first3=K. |last3=Jiang |first4=S. |last4=Fifta |first5=P. |last5=Forster |first6=V. |last6=Ginzburg |first7=C. |last7=Handa |first8=H. |last8=Kheshgi |first9=S. |last9=Kobayashi |first10=E. |last10=Kriegler |first11=L. |last11=Mundaca |first12=R. |last12=Séférian |first13=M. V. |last13=Vilariño |title={{Harvnb|IPCC SR15|2018}} |pages=93–174 }}