Table 1.
Summary of the THI-based milk loss estimation models.
Fig 1.
Changes in mean daily temperature according to the 11-member spatially-coherent RCM projection ensemble for the summer period (April-September) in the UK.
The vertical bars denote the range between the minimum and the maximum values predicted by the 11 climate projections. Baseline period: 2010s.
Fig 2.
Maps of annual milk loss for each THIthr and the CV for the 2010s, 2030s, 2050s, 2070s and 2090s in the UK.
CV of 1980 values per each cell.
Table 2.
Statistical description of heat stress days and milk loss values in the 11 UK NUTS-1 regions.
Table 3.
Uncertainty (measured by CV, %) of milk loss projections originating from different sources.
Fig 3.
Changes of average annual milk loss values calculated with six different milk loss methods (THIthr = 70) for a 25×25 km grid cell in South-East England (centroid: 51.0°N, 0.7°W).
Form of the fitted exponential curve: AML = a×eb×(y-2010); M1-2: a = 27.86, b = 0.0234, SEa = 1.68, SEb = 0.00074, R2 = 0.989, NRMSE = 7.4%; M3-4: a = 6.13, b = 0.0251, SEa = 0.456, SEb = 0.0009, R2 = 0.986, NRMSE = 6.6%; M5-6: a = 17.19, b = 0.0229, SEa = 1.11, SEb = 0.00079, R2 = 0.986; NRMSE = 6.8%. U test showed significant difference (P < 0.001) between the milk loss calculation methods: M1-2 different from M3-4 and both pairs different from M5-6.
Fig 4.
Changes in the number of days affected by heat stress (HS) calculated with the St-Pierre method (see M2 method description; THIthr = 70) for a 25×25 km grid cell in South-East England (centroid: 51.0°N, 0.7°W).
Triangles (and the fitted dotted linear) denote the days with heat stress that are detected only by the sub-daily methods (THId<THIthr and THImax>THIthr). Circles (and the fitted exponential curve) denote the days with heat stress that are detected by both the sub-daily and daily methods (THId>THIthr). Circles: number of heat stress days = a×eb×(y-2010), a = 9.69, b = 0.0199, SEa = 0.523, SEb = 0.00077, R2 = 0.91, NRMSE = 16.2%; Triangles: number of heat stress days = a×(y-2010)+b, a = 0.23, b = 38.28, SEa = 0.0184, SEb = 0.95, R2 = 0.639; NRMSE = 15.7%.
Fig 5.
Frequency and length of heat waves (HW) in the UK.
The presented values are the average of 11 UKCP09 SCP climate projections.
Table 4.
Income loss of average size dairy farms in different UK NUTS-1 regions due to heat stress (£/y) assuming no mitigation actions are taken.