Table 1 Discovered and estimated absolute (non-standardised) linear direct causal effects for the discovered graph (Fig. 2a)
From: Decreasing aerosols increase the European summer diurnal temperature range
Link | Climate effect | Causal sign | Causal effect estimate | Literature estimates |
|---|---|---|---|---|
1 | AOD → Cloud: aerosols serving as CNN/INPs and enhancing cloud formation (ACI, i.e, cloud fraction adjustment)16 | + | 0.6 [0.4; 0.8] | [0.59; 1.07] from16 |
2 | Cloud → SW: increased cloud cover blocks SW from reaching the surface9,80 | - | −105.3[−157.5; −59.9]Wm−2 | [−177; 0]Wm−2 from80 |
3 | SW \(\to \,{{\rm{T}}}_{\max }\): surface warming by SW absorption9,81 | + | 0.02* [0.004; 0.04] | 0.1K/Wm−2 from81 |
4 | CC \(\to \,{{\rm{T}}}_{\max }\): non-radiative cooling of clouds, e.g., evaporative cooling following precipitation51. This effect is only significant during summer and short time scales and the reversed, i.e, reduced precipitation, has been identified as a driver of summer heat waves82. | - | −3.3* [−6.05; −1.1] | −0.7151 |
5 | AOD → SW: ARI16 through scattering and absorption. Because clouds are represented as cloud area fraction, cloud albedo changes (Twomey effect17) are also contained in this link. | - | −66.4*[−99.8; −30.95] | ARI: [−27; −20]Wm−2 from16 for global annual estimates |
6 | Clouds \(\to \,{{\rm{T}}}_{\min }\): LW warming at night9 | + | 2.1 [−0.3; 4.5] | [1; 3] K83 |
7 | AOD \(\to \,{{\rm{T}}}_{\min }\) : LW warming through ARI at night18,19 | + | 1.9 [0.6; 3.6] | [0.39; 4.56] K (methods) |
8 | \({{\rm{T}}}_{\min }\,\to \,{{\rm{T}}}_{\max }\) | + | 0.5 [0.2; 0.8]; | [0;1] due to |
9 | \({{\rm{T}}}_{\max }\,\to \,{{\rm{T}}}_{\min }\): temporal auto-dependency from sequential measurements | + | 0.4 [0.3; 0.5] | temporal auto-dependency |