Climate Change and Social- Ecological Vulnerability Index in the Brazilian Amazon: A study with a cascade model approach

The Brazilian Amazon is a powerful Ecosystem Service (ES) provider. Simultaneously, many Amazonian local communities still preserve an intrinsic economic and cultural relationship in this Social-Ecological System. Paradoxically, the region concentrates a significant portion of the nation's poorest people, demonstrating the risks and susceptibility to socio-ecological vulnerability that region. Thus, the Amazon Forest dieback hypothesis predicts that the increased CO₂ (eCO₂), rising temperatures and droughts may push the forest toward a tipping point, which would bring a new composition of ES and would reflect on regional economic - cultural ways of living, as well as, social wellbeing and health. Hence, the research employed a cascade model using the Functional Diversity (FD) approach. The aim was to assess the impact of climate changes on CO₂ storage related to Ecosystem Services and their implications for the adaptation capacity of both rural and urban populations in the Brazilian Amazon. The initial analysis, using the CAETE model, evaluated vegetation FD responses in a scenario of 50% precipitation reduction. This revealed a shift in plant composition towards drought-related strategies, leading to a 37-49% reduction in total carbon storage in the basin, resulting in increased carbon release into the atmosphere. This result translates direct impacts to global and local climate regulation and indirect to shifting of water flux and to native provisioning services. The second evaluating was on social dimension ambit, through drafting of Social Ecological Vulnerability Index (SEVI) with secondary data of the municipalities of Manaus, Itacoatiara e Silves in the state of Amazonas and Ilha de Cotijuba in the Belém city in the state of Pará. The SEVI points out that the common factor of the vulnerability among the municipalities was the indicators of the socio-climate exposure for susceptibility to disasters, to rising temperature and FD changes. The SEVI result summed to FD modelling demonstrate that the social well-being of communities is threated due to the impacts on the native ES, even though they are placed in the one of most biodiverse forest from the globe. In addition, the susceptibility to diseases related to climate change increases in the regions greater urbanized (score 2.5, in the range from 0 low to 4 high vulnerability) with in turn can undermine the public health system in the urban centres in expanding in the Amazonia. Thus, the SEVI reveals that the impacts, stemming from the shifting FD of the modelled plant community, do not merely pose a distant threat to social well-being, health, and income; instead, they exacerbate socio-ecological vulnerability. In view that, people recognize and link hazards in infrastructure (ES for erosion control), mobility, and food supply (ES for water flow, fish, and wild food). Therefore, all the results support the challenges for the development of public policies of climate adaptation involving social health, future maintenance of provisioning native ES, above all in the municipalities with inadequate socioeconomic indicators