拯救生物多样性的代价：全球经济能否承受“半个地球”计划

The economics of the Half-Earth scenario 12 November 2025 Content Page 3-4Executive Summary Page 5-9Recent shifts in the world’s living systems Page 10-15Nature’s role in building economic stability Page 16-21Economic implications of the Half-Earthscenario Page 22-25Beyond the Half-Earth scenario Page 26-28Bridging the biodiversity finance gap SummaryExecutive •Climate goals are unattainable without a healthy planet.Yet naturalcapital and ecosystem services are deteriorating at an alarming pace. TheLiving Planet Index shows a -73% decline in wildlife populations over the pastfive decades. Without rapid action to halt and reverse biodiversity loss, theecosystems that support food, water, climate stability and economic growthwill continue to erode. Hazem KricheneSenior Economist, Climatehazem.krichene@allianz.com •Nature underpins more than half of global GDP.Continued biodiversityloss could slash global GDP by -2.3% by 2030, relative to a baseline in whichbiodiversity remains at 2020 levels, with far deeper impacts on developingeconomies (-7% to -10%). Drivers include deforestation, pollution, intensiveagriculture and climate change. These risks flow through two channels:physical risks, as ecosystem services like pollination and water regulation fail,and transition risks, as policy, market and consumer shifts raise compliancecosts, strand assets and reshape competitiveness. Ecological decline is now adirect macro-financial threat. Katharina UtermoehlHead of Thematic and Policy Researchkatharina.utermoehl@allianz.com •The Half-Earth scenario, which proposes to protect 50% of land on theplanet, offers a bold pathway to restore critical ecosystems.Large scaleProtection of land would restore biodiversity to 2010 levels. Such a transitionpathway brings adjustment costs: by 2050, global cropland could shrink-11%, raising food prices by +15% and global CPI by +24%, with developingeconomies seeing sharper GDP impacts (up to -19%) than advanced markets(around -4%). Our findings highlight that while biodiversity protection isvital, it must be accompanied by inclusive economic transition strategies toavoid widening global inequality. But these costs are far lower than lossesfrom unchecked nature decline. For example, the loss of just one ecosystemservice such as pollination would inflict greater damages than large-scaleconservation in major economies, such as Europe, the UK and the US. Markus ZimmerSenior Economist, ESGmarkus.zimmer@allianz.com •Expanding protected areas alone cannot deliver recovery.On the supplyside, sustainable intensification through regenerative agriculture, precisionfarming, soil restoration and crop diversification can raise yields withoutexpanding farmland. Global trade in certified sustainable commodities canreduce pressure on biodiversity hotspots while maintaining market access fordeveloping producers. On the demand side, dietary shifts toward plant-richdiets and reduced meat consumption, alongside food waste reduction, arecrucial to free land for restoration and cut emissions. Simulation models showthat isolated actions achieve limited gains, but when conservation, sustainableproduction and responsible consumption advance together, the Living PlanetIndex more than doubles by 2100, restoring biodiversity to levels above thoseof 1970. •Closing the USD700bn annual biodiversity finance gap is essential.Currentflows total just USD143bn, though private investment has grown rapidly, fromUSD9.4bn in 2020 to over USD100bn in 2024, driven by new nature-focusedfunds, credit instruments and green bonds. The Kunming-Montreal GlobalBiodiversity Framework targets international financial flows of USD20bn peryear by 2025 and USD30bn by 2030 but achieving this will require a majorscale-up of blended finance, stronger policy incentives and standardizedbiodiversity taxonomies to guide capital. •Finance will determine whether biodiversity recovery succeeds, andinsurers are on the front line.They can underwrite restoration projects,offer ecosystem-based coverage and create transition products that rewardsustainable practices. By valuing and protecting natural assets, insurers alsoshield themselves from the rising physical and liability risks of ecologicaldecline, such as flood losses from wetland degradation or stranded assetsas regulation tightens. Investors, too, are stepping up. Biodiversity-themedfunds now exceed USD1.6bn, while portfolio managers increasingly use toolslike the Global Biodiversity Score to align investments with nature goals.Public programs are amplifying these efforts: the EU’s InvestEU aims tomobilise EUR10bn for natural capital, and France’s SNCRR initiative is buildingbiodiversity credit markets. To meet the Kunming–Montreal targets, includingUSD200bn a year in biodiversity finance by 2030, financial institutions mustexpand capital flows, strengthen safeguards and make biodiversity impactreporting as standard as carbon disclosure. Recent shifts inthe world’s living sys