**5. Conclusions**

Quantifying the potential consequences of warming winters on chill accumulation may have implications for long-term orchard managemen<sup>t</sup> and land use planning and may provide insights useful for climate-informed decision making for a variety of perennial crops that require winter chill. Our results show that anthropogenic climate change has negatively a ffected chill accumulation in the SEUS over the observed 1981–2017 period, and that ongoing climate change is likely to continue to reduce chill accumulation, with notable impacts on high- and moderate-chill peach cultivars in Georgia. We also highlight the importance of examining interannual variability when assessing climate change risks to agriculture, be that impacts to crop climatic niche or crop yield [19,52]. The adaptation measures (e.g., investments in lower-chill varieties) may be necessary in order for the SEUS, particularly Georgia, to continue to cultivate the crop that has historically been central to its cultural identity. Further, given the relationship between mild winter temperatures, early bloom, and damages due to a false spring—as also seen in 2017—we recommend future work consider the interaction between multiple agro-climatic variables to provide a more complete assessment of future crop suitability and identify the most appropriate adaptive e fforts. Finally, as our study employs a methodology that is applicable across other geographic locations, perennial crop cultivars, and agro-climatic metrics, we recommend that similar work be undertaken across agricultural systems and regions to help identify potential crop-specific risks and adaptation opportunities.

**Author Contributions:** Conceptualization, L.E.P. and J.T.A.; Methodology, L.E.P. and J.T.A.; Formal Analysis, L.E.P. and J.T.A.; Writing—Original Draft Preparation, L.E.P. and J.T.A.; Writing—Review & Editing, L.E.P. and J.T.A.; Visualization, L.E.P. and J.T.A.; Supervision, J.T.A.; Project Administration, J.T.A.; Funding Acquisition, L.E.P. and J.T.A.

**Funding:** This research was partially supported by the USDA's Northwest Climate Hub under award 15-JV-11261944-093.

**Acknowledgments:** The authors wish to acknowledge the feedback and local context provided by University of Georgia Assistant Professor and Extension Specialist Dario Chavez, and University of Georgia Agricultural Climatologist Pamela Knox. The authors also wish to acknowledge Katherine Hegewisch for her e fforts in incorporating chill accumulation data into the ClimateToolbox. Finally, the authors wish to thank four anonymous reviewers and the journal editor for their comments, which improved the quality of the manuscript.

**Conflicts of Interest:** The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
