John Latham and Alan Gadian Coral Bleaching (in preparation) Hurricane amelioration Meridional Heat flux 1

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Table 1. Changes in sea surface temperatures between the three experiments described in Section 3.1, all values in K. The three regions, Caribbean, Great Barrier Reef and Polynesia are shown in black rectangles in Figure 1. Region 2xCO 2 – Control 2xCO 2 +MCB – Control Global 0.67 –0.12 Caribbean 0.53 –0.04 Great Barrier Reef Polynesia 0.64 –0.58 [NB: 2xCO 2 + All Clouds MCB – Control: Global temperature change -6.5 K] 4

Table 2. The number of mild and severe bleaching events over a 20-year period for the three simulations: Control, 2xCO 2, and 2xCO 2 +MCB. Bleaching events are calculated based on two heat- stress thresholds: 1°C above the climatological maximum, and 2.45 x SD max above the climatological maximum. Climatological maxima were calculated based on the Control. Note that the Control provides the background number of bleaching events expected under normal conditions. Number in parentheses are the number of ocean cells within each reef region. Control2xCO 2 2xCO 2 +MCB Region MildSevereMildSevereMildSevere Caribbean (439) 1°C SD max Great Barrier Reef (179) 1°C SD max French Polynesia (899) 1°C SD max

Controlled Hurricane Weakening via Marine Cloud Brightening Figure 1. Sea surface temperature (SST) differences ( o C) between conditions 2xCO 2 and 1xCO 2, within an area bounded by latitudes 30 degrees North & 30 degrees S and longitudes 110 degrees West and 60 degrees East. There is no seeding. The inner, dashed rectangle defines the hurricane development region HDR. The average difference in SST (from Control) is 0.66 o C in the HDR and 0.53 o C globally. Figure 2. SST differences between patchy seeding at 2xCO 2 and Control (1xCO 2, no seeding). The average difference in SST (from Control) is 0.13 o C in the HDR and o C globally 6

Figure 3. SST differences between full seeding at 2xCO 2 and Control (1xCO 2, no seeding). The average difference in SST (from Control) is -4.0 o C in the HDR and o C globally Figure 4. SST differences between full seeding at 1xCO 2 and Control (1xCO 2, no seeding). The average reduction in SST produced by seeding is -4.6 o C in the HDR and o C globally 7

Controlled Hurricane Weakening via Marine Cloud Brightening See poster Figure CO 2 Seed HDR Global 1x2 None x2 3*Patch x2 Full x1 Full Table 1. Departures ( o C) of average Sea Surface Temperature (SST) values from Control (no seeding, 1xCO 2 ) for the four figures (Fig. 1-4 ) presented below. Seed is the type of seeding, HDR is the Hurricane Development Region (defined in the text), and the atmospheric CO 2 concentration is either the current value (Control) or twice the pre- industrial value. 8

Meridional Heat Flux ---- see poster Figure 1 Plots of the radiative balance and MHF in Wunsch (2005) and values from the HadGEM1 climate model. (Martin et al, 2006) Figure 3. Plot showing the MHF for four geoengineering simulations in HadGEM1. 9

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