Climate change futures: health, ecological and economic dimensions

28 | THE CLIMATE CONTEXT TODAYCCF-I: GRADUAL WARMINGWITH INCREASING VARIABILITY:ESCALATING IMPACTSThis baseline scenario explores an ensemble of conditions,events and impacts that have begun to appearin association with gradual anthropogenic climatechange. Most of the outcomes envisioned in CCF-I areprojections from current trends. As climate becomesmore variable, weather extremes are projected to playan expanding role in the spread of disease and disturbanceof ecological processes. In general, this scenarioenvisions the majority of events unfolding nearthe upper ranges of historical norms, in terms of intensity,duration and geographic extent.In this scenario, thermal extremes and shifting weatherpatterns give rise to elevated rates of heat-related illnessand more vector-borne disease. Increased volumesof dust swept vast distances, more photochemicalsmog and higher concentrations of CO 2-linkedaeroallergens (pollen and mold) drive up rates of asthma,which already afflicts one in six high school childrenin the US. CCF-I envisions a perceptible impairmentof public health as a result of these ills, whethermeasured by morbidity and mortality, disability adjustedlife years (DALYs) lost, or by the incremental medicalresources devoted to the emerging problems andthe associated rise in insurance costs. Ecological stressfrom warming, greater extremes and pest infestationswould further undermine Earth’s life-support systemsand the public health benefits (Cifuentes et al. 2001)delivered by a healthy environment.CCF-I would involve more frequent and intense heatwaves. Lost productivity during hot months wouldbecome more routine and costly, and air-conditioning,thus electric power grid-capacity, would be stretchedseverely. Air quality issues would return to the frontburner in the public eye as the extreme heat coupledwith noxious air masses overwhelm pollution-abatementmeasures.Floods would be more frequent and severe as well inthe future envisaged in CCF-I. Some would be theresult of storm surges in coastal areas, while otherswould result from an increased number of heavy precipitationevents and overflowing rivers. The boundariesof floodplains could expand and more flooding,coupled with rising sea levels, would mean structuresexperience more moisture-related damage and drinkingwater systems become compromised more frequently.Large numbers of people would suffer fromwater-related diseases.The impacts on natural systems can directly and indirectlyaffect human health. Agricultural diseases andextreme events that hamper food production affectnutrition. CCF-I envisions steady increases in pests thatharm important crops, with less food of lower qualitybeing produced at a higher cost. Animal and livestockdiseases may also increase, and some may jump tohumans.Maintaining biodiversity of plants and animals is keyto preserving forest health (Daszak et al. 2000). Evengradual climate change, however, can produce asurge of forest pests and eliminate “keystone” speciesthat perform essential functions. Loss of forested tractsto drought and pests would lead to more wildfires,causing deaths, injuries and extensive property damage.The human losses associated with fire fighting inforested areas would increase, as would respiratory diseaseregionally.Coral bleaching and diseases of coral reefs wouldaccelerate in CCF-I. This oldest of Earth’s ecosystemsprovides multiple and some irreplaceable services: asa buffer from storm surges, as nurseries for many fish,and as a source of income through tourism. The potentialfate of coral around the globe — when already60% of reefs are threatened — serves as a grim illustrationof the potential ecological and economic consequencesof losing essential habitat. For the insuranceindustry, weather-related property losses and businessinterruptions would continue to rise at rates observedthrough the latter 20th century and the beginning ofthe 21st. The insured share of these losses wouldincrease, as more developed areas are affected, andunderwriting becomes more problematic. This placesstress on the solvency of some insurance companiesand even affects the strongest firms. In this scenario,climate-change effects are a risk that has emerged.Corporations face more environmentally related litigation(and associated insurance payouts), both as emittersof greenhouse gases and from non-compliancewith new regulations in a changed political climate inwhich public alarm mounts. Climate impacts begin tohave a more noticeable effect on insured lives, a newdevelopment for the life/health branch of the insuranceindustry. Epidemics and extremes impair the “climateof investment” in some regions and affect financialservices and investment portfolios. In sum, the insuranceindustry and investors would face acceleratingtrends that weaken returns and profitability.