Estimation of the economic impact of temperature changes induced by a shutdown of the thermohaline circulation: an application of FUND

The integrated assessment model FUND 2.8n is applied in an assessment to estimate the magnitude of the general market and non-market impacts of temperature changes caused by a possible shutdown of the thermohaline circulation (THC). The monetized impacts of this change in environmental conditions are determined for 207 individual countries for two scenarios: one warming scenario in which the THC weakens but remains intact, and another in which the THC breaks down. Eight different response patterns are identified. The dominant pattern is that a THC shutdown has an offsetting effect on the underlying warming trend. Depending on whether the impacts of warming are initially beneficial or detrimental, the economic effects of a THC shutdown show distinct regional variability. Key economic sectors affected are water resources and energy consumption, as well as cardiovascular and respiratory diseases among health impacts. The maximum national impact of a shutdown of the THC turns out to be of the magnitude of a few per cent of GDP, but the average global impact is much smaller. The results indicate that the temperature effect of a THC shutdown does not create an insurmountable economic threat on a global scale, but may cause severe damages to individual countries. However, a consideration of other climatic impacts such as precipitation and sea level changes is likely to alter the identified trends in economic development.

本研究采用综合评估模型FUND 2.8n开展一项评估，旨在估算由热盐环流（thermohaline circulation, THC）可能中断所引发的气温变化所带来的整体市场与非市场影响规模。本评估针对207个国家，针对两种情景量化了该环境条件变化的货币化影响：其一为热盐环流减弱但维持完整的变暖情景，其二为热盐环流彻底崩溃的情景。研究共识别出八种不同的响应模式。占主导地位的模式为：热盐环流中断会对潜在变暖趋势产生抵消效应。根据变暖影响最初为有益还是有害，热盐环流中断所带来的经济影响会呈现出显著的区域异质性。受影响的核心经济部门涵盖水资源与能源消费领域，健康影响层面则涉及心血管疾病与呼吸系统疾病。热盐环流中断所带来的单个国家最大影响约占国内生产总值（Gross Domestic Product, GDP）的数个百分点，但全球平均影响则要小得多。研究结果表明，热盐环流中断所带来的气温效应并不会在全球层面造成难以应对的经济威胁，但可能会对个别国家造成严重损害。然而，若将降水、海平面变化等其他气候影响纳入考量范围，可能会改变已识别出的经济发展趋势。