Increase in crop losses to insect pests in a warming climate

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Science  31 Aug 2018:
Vol. 361, Issue 6405, pp. 916-919
DOI: 10.1126/science.aat3466
  • Fig. 1 Global loss of crop production owing to the impact of climate warming on insect pests.

    Crop production losses for (A) wheat, (B) rice, and (C) maize are computed by multiplying the fractional change in population metabolism by the estimated current yield loss owing to insect pests, summed over worldwide crop locations. Results are plotted versus mean global surface temperature change, for four climate models (13), for two different values of the demographic parameter governing survival during diapause (ϕo = 0.0001, asterisks; ϕo = 0.001, circles), and for the metabolic effect alone (triangles). Mt/yr, metric megatons per year. The year in which a given global mean temperature anomaly is reached (D) depends on the greenhouse gas emissions scenario (RCP, representative concentration pathway) and varies across models (shading) owing to uncertainty in climate sensitivity to those emissions (13).

  • Fig. 2 Projected geographic pattern of change in crop yield losses to insect pests in a 2°C-warmer climate.

    Results are mapped for the fractional (percent) increase in crop yield loss owing to pests from both metabolic and demographic effects (ΔL/L) for (A) wheat, (B) rice, and (C) maize. The zonal median change is plotted for the separate contribution of demographic effects (Δn/n, blue) and metabolic effects (ΔM/M, red) for (D) wheat, (E) rice, and (F) maize. Results are shown for a range of life history traits in the longitudinal average curves (right panels). The metabolic effect uses activation energies (Eo) with a mean (0.65 eV) and standard deviation (±0.15 eV) for insects (12). The demographic effect assumes a range of ϕo values from 0.0001 to 0.01. All results are averaged over multiple climate models (13), in all years when the global mean surface temperature is 2 ± 0.1°C greater than in the late 20th century.

  • Fig. 3 Predicted regional increases in crop losses to insect pests in a 2°C-warmer climate.

    The change in future yield loss for each country is shown for the median grid cell within each country and plotted as a function of its median present-day crop yield per unit of planted area for (A) wheat, (B) rice, and (C) maize. The symbol size is scaled to total current production for each country, and color indicates the United Nations region. For each crop, the five countries with the highest current production are labeled and circled. The geographic burden of additional future production losses is shown in the pie charts. A full list of effects by region and country can be found in tables S1 to S5.

  • Increase in crop losses to insect pests in a warming climate

    Curtis A. Deutsch, Joshua J. Tewksbury, Michelle Tigchelaar, David S. Battisti, Scott C. Merrill, Raymond B. Huey, Rosamond L. Naylor

    Materials/Methods, Supplementary Text, Tables, Figures, and/or References

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    • Materials and Methods 
    • Figs. S1 to S7
    • Tables S1 to S5
    • References 

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