Table 2.
Number of and exposure to high-mortality heatwaves projected under scenarios of climate change (RCP4.5, RCP8.5), population change (SSP3, SSP5), adaptation to climate change (none, lagged, on-pace), and health-based model. Each estimate gives the mean across ensemble members of that climate scenario (14 ensemble members for RCP4.5; 29 for Present and RCP8.5). Numbers of high-mortality heatwaves are totaled across all 82 study communities. Exposures are yearly averages, in millions of person-days per year, totaled across all 82 communities. Ranges across ensemble members are given in parentheses, and the percent of all heatwaves or heatwave exposure projected to be from high-mortality heatwaves is given after the comma in each table cell
| Model | Present | Climate scenario: RCP4.5 | Climate scenario: RCP8.5 | ||
|---|---|---|---|---|---|
| Population scenario: SSP3 | Population scenario: SSP5 | Population scenario: SSP3 | Population scenario: SSP5 | ||
| Number of high-mortality heatwaves over a 20-year period | |||||
| No adaptation | |||||
| Classification tree | 6 (5, 7), 0.22 % | 43 (35, 49), 0.40 % | 43 (35, 49), 0.40 % | 50 (47, 55), 0.39 % | 50 (47, 55), 0.39 % |
| Bagging | 6 (5, 6), 0.19 % | 41 (33, 46), 0.37 % | 41 (34, 46), 0.38 % | 49 (45, 53), 0.38 % | 49 (46, 54), 0.38 % |
| Boosting | 5 (4, 5), 0.17 % | 36 (29, 40), 0.33 % | 36 (29, 40), 0.33 % | 43 (40, 47), 0.33 % | 43 (40, 47), 0.33 % |
| Simple | 6 (5, 6), 0.19 % | 48 (40, 55), 0.45 % | 48 (40, 55), 0.45 % | 76 (70, 85), 0.59 % | 76 (70, 85), 0.59 % |
| Lagged adaptation | |||||
| Classification tree | 6 (5, 7), 0.22 % | 15 (11, 21), 0.14 % | 15 (11, 21), 0.14 % | 24 (17, 30), 0.18 % | 24 (17, 30), 0.18 % |
| Bagging | 6 (5, 6), 0.19 % | 13 (9, 19), 0.12 % | 14 (9, 20), 0.13 % | 22 (16, 29), 0.17 % | 22 (17, 29), 0.17 % |
| Boosting | 5 (4, 5), 0.17 % | 12 (8, 16), 0.11 % | 12 (8, 16), 0.11 % | 19 (14, 25), 0.15 % | 19 (14, 25), 0.15 % |
| Simple | 6 (5, 6), 0.19 % | 15 (11, 20), 0.14 % | 15 (11, 20), 0.14 % | 28 (22, 36), 0.22 % | 28 (22, 36), 0.22 % |
| On-pace adaptation | |||||
| Classification tree | 6 (5, 7), 0.22 % | 6 (4, 7), 0.05 % | 6 (4, 7), 0.05 % | 4 (3, 6), 0.03 % | 4 (3, 6), 0.03 % |
| Bagging | 6 (5, 6), 0.19 % | 5 (4, 6), 0.04 % | 5 (4, 6), 0.05 % | 4 (3, 5), 0.03 % | 4 (3, 5), 0.03 % |
| Boosting | 5 (4, 5), 0.17 % | 4 (3, 5), 0.04 % | 4 (3, 5), 0.04 % | 3 (2, 4), 0.03 % | 3 (2, 4), 0.03 % |
| Simple | 6 (5, 6), 0.19 % | 5 (5, 6), 0.05 % | 5 (5, 6), 0.05 % | 5 (4, 6), 0.04 % | 5 (4, 6), 0.04 % |
| Exposure to high-mortality heatwaves, in millions of person-days per year | |||||
| No adaptation | |||||
| Classification tree | 2 (2, 3), 0.36 % | 30 (24, 36), 0.70 % | 53 (42, 64), 0.70 % | 53 (45, 58), 0.72 % | 92 (79, 102), 0.72 % |
| Bagging | 2 (2, 2), 0.32 % | 29 (24, 35), 0.67 % | 52 (43, 62), 0.68 % | 52 (44, 57), 0.71 % | 93 (79, 101), 0.71 % |
| Boosting | 2 (1, 2), 0.28 % | 25 (20, 31), 0.59 % | 44 (36, 54), 0.59 % | 46 (39, 50), 0.62 % | 80 (68, 88), 0.62 % |
| Simple | 2 (2, 2), 0.29 % | 30 (25, 33), 0.68 % | 52 (45, 58), 0.68 % | 69 (65, 77), 0.89 % | 122 (114, 136), 0.89 % |
| Lagged adaptation | |||||
| Classification tree | 2 (2, 3), 0.36 % | 14 (9, 21), 0.33 % | 24 (16, 37), 0.33 % | 33 (25, 42), 0.44 % | 57 (44, 73), 0.44 % |
| Bagging | 2 (2, 2), 0.32 % | 13 (8, 20), 0.29 % | 23 (15, 37), 0.30 % | 31 (24, 41), 0.41 % | 56 (44, 72), 0.42 % |
| Boosting | 2 (1, 2), 0.28 % | 11 (7, 17), 0.25 % | 19 (12, 30), 0.25 % | 26 (21, 35), 0.36 % | 47 (36, 61), 0.36 % |
| Simple | 2 (2, 2), 0.29 % | 12 (10, 16), 0.29 % | 22 (17, 29), 0.29 % | 40 (34, 52), 0.51 % | 71 (60, 91), 0.51 % |
| On-pace adaptation | |||||
| Classification tree | 2 (2, 3), 0.36 % | 6 (4, 8), 0.14 % | 10 (7, 15), 0.14 % | 8 (5, 10), 0.11 % | 13 (9, 17), 0.11 % |
| Bagging | 2 (2, 2), 0.32 % | 5 (4, 7), 0.12 % | 9 (7, 13), 0.12 % | 7 (5, 9), 0.09 % | 13 (9, 17), 0.09 % |
| Boosting | 2 (1, 2), 0.28 % | 4 (3, 6), 0.10 % | 7 (5, 11), 0.10 % | 6 (4, 7), 0.08 % | 10 (7, 13), 0.08 % |
| Simple | 2 (2, 2), 0.29 % | 5 (4, 6), 0.12 % | 9 (8, 10), 0.12 % | 10 (8, 12), 0.13 % | 18 (15, 22), 0.13 % |