Protected areas' role in climate-change mitigation

Abstract

Globally, 15.5 million km(2) of land are currently identified as protected areas, which provide society with many ecosystem services including climate-change mitigation. Combining a global database of protected areas, a reconstruction of global land-use history, and a global biogeochemistry model, we estimate that protected areas currently sequester 0.5 Pg C annually, which is about one fifth of the carbon sequestered by all land ecosystems annually. Using an integrated earth systems model to generate climate and land-use scenarios for the twenty-first century, we project that rapid climate change, similar to high-end projections in IPCC's Fifth Assessment Report, would cause the annual carbon sequestration rate in protected areas to drop to about 0.3 Pg C by 2100. For the scenario with both rapid climate change and extensive land-use change driven by population and economic pressures, 5.6 million km(2) of protected areas would be converted to other uses, and carbon sequestration in the remaining protected areas would drop to near zero by 2100.

Keywords: Carbon sequestration; Climate change; Global carbon cycle; Mitigation; Protected areas.

Fig. 1

The dynamically linked modeling system. It consists of an economic model (EPPA), a terrestrial biogeochemistry model (TEM) using climate output from an atmospheric chemistry and climate model (Reilly et al. 2012). The creation of plant biomass, known as net primary production (NPP) is calculated within TEM as the difference between GPP and R _A (see text). Within the modeling system, the combination of TEM and the atmospheric chemistry and climate models are referred to as the MIT Earth Systems Model (MESM)

Fig. 2

Current protected areas (green shade) in each EPPA region (units are million km²). AFR Africa, ANZ Australia and New Zealand, ASI Higher Income East Asia, CAN Canada, CHN China, EET Eastern Europe, EUR European Union, FSU Former Soviet Union, IDZ Indonesia, IND India, JPN Japan, LAM Latin America, MES Middle East, MEX Mexico, ROW Rest of the World, USA United States of America

Fig. 3

Projected changes by the end of the century in the extent of protected areas in the NP simulation, which includes allowing pressures from a growing and wealthier world population to reduce the extent of protected areas

Fig. 4

Carbon sequestration rates by land ecosystems for current conditions (2005–2010) and under two future scenarios at the end of the twenty-first century (2095–2100): A current conditions; B the FP scenario; and C the NP scenario. In the FP scenario, the extent of protected areas is constant over the twenty-first century, while in the NP scenario, the extent of protected areas is reduced in response to land-use pressures from a growing and wealthier world population

Fig. 5

Changes in global fossil fuel emissions (a), atmospheric carbon dioxide (CO₂) concentrations (b) and changes in global mean air temperatures from year 2000 (c) for the BAU climate scenario