Climate change futures: health, ecological and economic dimensions

PREAMBLEHurricane Katrina4 | PREAMBLEWhat was once a worst-case scenario for the US GulfCoast occurred in August 2005. Hurricane Katrinakilled hundreds and sickened thousands, created onemillion displaced persons, and sent ripples throughoutthe global economy, exposing the vulnerabilities of allnations to climate extremes.While no one event is conclusive evidence of climatechange, the relentless pace of severe weather —prolonged droughts, intense heat waves, violentwindstorms, more wildfires and more frequent “100-year” floods — is indicative of a changing climate.Although the associations among greater weathervolatility, natural cycles and climate change aredebated, the rise in mega-catastrophes and prolongedwidespread heat waves is, at the very least, aharbinger of what we can expect in a changing andunstable climate.For the insurance sector, climate change threatens theLife & Health and Property & Casualty businesses, aswell as the health of insurers’ investments. Managingand transferring risks are the first responses of theinsurance industry — and rising insurance premiumsand exclusions are already making front-page news.Many corporations are changing practices and someare seizing business opportunities for products aimedat reducing risks. Corporations and institutionalinvestors have begun to consider public policiesneeded to encourage investments in clean energy ona scale commensurate with the heightened climate andenergy crises.The scientific findings underlying the unexpected paceand magnitude of climate change demonstrate thatgreenhouse gases have contributed significantly to theoceans’ warming at a rate 22 times more than theatmosphere since 1950. Enhanced evaporation fromwarmer seas fuels heavier downpours and sequencesof storms.Polar ice is melting at rates unforeseen in the 1990s.As meltwater seeps down to lubricate their base, someGreenland outlet glaciers are moving 14 kilometersper year, twice as fast as in 2001, making linearprojections for sea level rise this century no longerapplicable. North Atlantic freshening — from meltingice and Arctic rainfall — is shifting the circulationpattern that has helped stabilize climates for millennia.Indeed, the slowing of the Ocean Conveyor Belt andthe degree of storm destructiveness are occurring atrates and intensities that past models had projectedwould occur much later on in this century.Warm ocean waters fuel hurricanes. This image depicts the three-dayaverage of sea surface temperatures (SSTs) from August 25-27, 2005,and the growing breadth of Hurricane Katrina as it passed over thewarm Gulf of Mexico. Yellow, orange and red areas are at or above82 0 F (27.7°C), the temperature needed for hurricanes to strengthen. Bylate August SSTs in the Gulf were well over 90 0 F (32.2°C).Source: NASA/Goddard Space Flight Center/ScientificVisualization StudioNonetheless, if we drastically reduce greenhouse gasemissions, our climate may reach a new andpotentially acceptable equilibrium, affording amodicum of predictability. Doing so, however, requiresa more sustainable energy mix that takes into accounthealth and environmental concerns, as well aseconomic feasibility to power our common future. Atthis time, energy prices and supplies, political conflictsand climate instability are converging to stimulate thedevelopment of a new energy plan.Expanded use of new energy-generation andefficiency-enhancing technologies, involving greenbuildings, solar, wind, tidal, geothermal, hybrids andcombined cycle energy systems, can become theengine of growth for this century. The financial sector,having first sensed the integrated economic impacts ofglobal climate change, has a special role to play: tohelp develop incentivizing rewards, rules andregulations.This report examines a wide spectrum of physical andbiological risks we face from an unstable climate. Italso aims to further the development of healthy, safeand economically feasible energy solutions that canhelp stabilize the global climate system. Thesesolutions should also enhance public health, improveenergy security and stimulate economic growth.– Paul Epstein and Evan Mills