GMO approvals under pressure: How climate shocks shape policy across nations

PLOS One | https://doi.org/10.1371/journal.pone.0332298 October 22, 2025 8 / 20 ranging from 0 to 1, combines the indicators including projected change in hydropower generation capacity, projected change of sea level rise impacts, dependence on imported energy, population living under 5m above sea level, electric- ity access, and disaster preparedness. A higher indicator means the infrastructure is more impacted by certain shock. The international agreement indicator, collected from prior work [27], measures whether a country subscribes to the two GMO-specific international agreements, i.e., Codex Alimentarius and the Cartagena Protocol on Biosafety. The UPOV indicator measured by prior work [28] measures country adherence to revisions of the International Convention for the Protection of New Varieties of Plants (UPOV). Tables 1 and 2 report the descriptive statistics for all estimated variables. 4. Methodology Following existing studies [29,30], this paper employs the local projection method to estimate the cumulative impacts of climate shocks on GMO approval events, rather than focusing on marginal effects. The advantage of using local projec- tions lies in their flexibility: they estimate the dynamic response of an outcome at different time horizons without requir- ing strong assumptions about the underlying data-generating process [31]. This approach is particularly suitable in our context, where previously approved GMO events may influence future approvals due to the long-term utility of these

Table 1. Descriptive statistics for number of climate shocks and control variables. Obs Mean St. Dev. Min Max Number of climate shocks All 5168 3.04 4.59 0 32 Cold wave 5168 0.12 0.37 0 3 Severe winter 5168 0.03 0.17 0 2 Flood 5168 1.43 2.27 0 20 Heatwave 5168 0.09 0.29 0 3 Drought 5168 0.11 0.34 0 3 Storm 5168 1.04 2.49 0 19 Controls Agricultural share 5164 7.33 8.74 0.03 57.14 UPOV dummy 5168 0.69 0.46 0 1 Infrastructure 4864 0.35 0.1 0.14 0.64 Developing country dummy 5168 0.53 0.5 0 1 Arable Land 5120 0.27 0.26 0.00 1.42 Log(GDP) 5168 9.11 1.42 4.72 11.73 https://doi.org/10.1371/journal.pone.0332298.t001 Table 2. Descriptive statistics for number of GMO approvals (Obs = 5168). Mean St. Dev. Min Max All approvals 0.77 1.75 0 18 Trait Insect Resistant 0.45 1.46 0 18 Herbicide Tolerance 0.66 1.58 0 15 Drought Tolerance 0.01 0.14 0 4 Yield Improvement 0.00 0.01 0 1 Note. The most widely used GMO traits thus far involve herbicide tolerance and insect resistance (Qaim 2020). https://doi.org/10.1371/journal.pone.0332298.t002