CC: Lecture 9

(Folke, 2006)

Resilience: The emergence of a perspective for social-ecological systems analyses - Resilience perspective used understand dynamics of social-ecological systems - emphasizes non-linear dynamics, thresholds, uncertainty and surprise, how periods of gradual change interplay with periods of rapid change and how such dynamics interact across temporal and spatial scales - Recent advances include understanding of social processes like, social learning and social memory, mental models and knowledge-system integration, visioning and scenario building, leadership, agents and actor groups, social networks, institutional and organizational inertia and change, adaptive capacity, transformability and systems of adaptive governance that allow for management of essential ecosystem services. - developed: human actions influenced capacity of ecosystems to generate resources and services. - humans integrated into the system - Challenges: clarifying the feedbacks of interlinked social-ecological systems, the ones that cause vulnerability and those that build resilience, how they interplay, match and mismatch across scales and the role of adaptive capacity in this context. - human-in-the environment perspectives, acceptance of the limitation of policies based on steady-state thinking - design of incentives that stimulate the emergence of adaptive governance for social-ecological resilience of landscapes and seascapes. - toward more sustainable development pathways is one of the great challenges for humanity in the decades to come.

(IPCC, 2019)

SR on Ocean and Cryosphere in a Changing Climate: Polar Regions: Synopsis: 1. Climate-induced changes to the polar cryosphere and oceans have global consequences and impacts. 2. Across many aspects, the polar regions of the future will appear significantly different from those of today. 3. Choices are available that will influence the nature and magnitude of changes, potentially limiting their regional and global impacts and increasing the effectiveness of adaptation actions. Key Knowledge Gaps and Uncertainty: - Overturning circulation in the Southern Ocean is a key factor that controls heat and carbon exchanges with the atmosphere, and hence global climate, however there are no direct measures of this and only sparse indirect indicators of how it may be changing. This is a critical weakness in sustained observations of the global ocean. - Snow depth on sea ice is essentially unmeasured, limiting mass balance estimates and ice thickness retrievals. Improved mechanistic understanding of the observed changes and trends in Antarctic sea ice is required, notably the decadal increase and very recent rapid retreat. This has consequences for climate, ecosystems and fisheries; however, lack of understanding and poor model performance translates to very limited predictive skill. - Trends in snow water equivalent over Arctic land are inadequately known, reducing confidence in assessments of snow's role in the water cycle and in insulating the underlying permafrost. Understanding of precipitation in the polar regions is critically limited by sparse observations, and there is a lack of understanding of the processes that drive regional variability in wetting/drying and greening/browning of the Arctic land surface. There is inadequate knowledge concerning carbon dioxide and methane emissions from land and sub-sea permafrost. - There are clear regional gaps in knowledge of polar ecosystems and biodiversity, and insufficient population estimates/trends for many key species. Biodiversity projections are limited by key uncertainties regarding the potential for organisms to adapt to habitat change and the resilience of foodweb structures. Relatedly, knowledge gaps exist concerning how fisheries target levels will change alongside environmental change and how to incorporate this into decision making. Similarly, there are knowledge gaps on the extent to which changes in the availability of resources to subsistence harvesters affects food security of households. - There is a need to better understand the evolution of polar glaciers and ice sheets, and their influences on global sea level. Longer and improved quantifications of their changes are required, especially where mass losses are greatest, and (relatedly) better attribution of natural versus anthropogenic drivers. Better understanding of the sensitivity of Antarctica to marine ice sheet instability is required, and whether recent changes in West Antarctica represent the onset of irreversible change. - There are critical gaps in knowledge concerning interactions between the atmosphere and specific elements of the polar ocean and cryosphere. Detailed assessment of atmospheric processes was outside the remit of this chapter, however such gaps limit understanding of ongoing and future trajectories of the polar regions and their climate systems. Relatedly, there is a paucity of studies analysing differences in the trajectories of polar cryosphere and ocean systems between low and very low greenhouse gas emission scenarios. - There are critical needs to better understand the efficacy and limits of strategies for reducing risk and strengthening resilience for polar ecosystems and people, including the contribution of practices and tools to contribute to climate resilient pathways. Knowledge on how to translate existing theoretical understandings of social-ecological resilience into decision making and governance is limited. There is limited understanding concerning the resources that are needed for successful adaptation responses and about the effectiveness of institutions in supporting adaptation. While the occurrence of regime shifts in polar systems is both documented and anticipated, there is little or no understanding of their preconditions or of indicators that would help pre-empt them.

(IPCC, 2019)

SR on Ocean and Cryosphere in a Changing Climate: Summary for Policy Makers: - All people on Earth depend directly or indirectly on the ocean and cryosphere. The global ocean covers 71% of the Earth surface and contains about 97% of the Earth's water. The cryosphere refers to frozen components of the Earth system - Around 10% of Earth's land area is covered by glaciers or ice sheets. Observed Physical Changes: -Over the last decades, global warming has led to widespread shrinking of the cryosphere, with mass loss from ice sheets and glaciers (very high confidence), reductions in snow cover (high confidence) and Arctic sea ice extent and thickness (very high confidence), and increased permafrost temperature (very high confidence). - Ice sheets and glaciers worldwide have lost mass (very high confidence). Between 2006 and 2015, the Greenland Ice Sheet9 lost ice mass at an average rate of 278 ± 11 Gt yr-1 (equivalent to 0.77 ± 0.03 mm yr-1 of global sea level rise)10, mostly due to surface melting (high confidence). In 2006-2015, the Antarctic Ice Sheet lost mass at an average rate of 155 ± 19 Gt yr-1 (0.43 ± 0.05 mm yr-1), mostly due to rapid thinning and retreat of major outlet glaciers draining the West Antarctic Ice Sheet (very high confidence). Glaciers worldwide outside Greenland and Antarctica lost mass at an average rate of 220 ± 30 Gt yr-1 (equivalent to 0.61 ± 0.08 mm yr-1 sea level rise) in 2006-2015. - Between 1979 and 2018, Arctic sea ice extent has very likely decreased for all months of the year. September sea ice reductions are very likely 12.8 ± 2.3% per decade. These sea ice changes in September are likely unprecedented for at least 1000 years. Arctic sea ice has thinned, concurrent with a transition to younger ice: between 1979 and 2018, the areal proportion of multi-year ice at least five years old has declined by approximately 90% (very high confidence). Feedbacks from the loss of summer sea ice and spring snow cover on land have contributed to amplified warming in the Arctic (high confidence) where surface air temperature likely increased by more than double the global average over the last two decades. Changes in Arctic sea ice have the potential to influence mid-latitude weather (medium confidence), but there is low confidence in the detection of this influence for specific weather types. Antarctic sea ice extent overall has had no statistically significant trend (1979-2018) due to contrasting regional signals and large interannual variability (high confidence). - It is virtually certain that the global ocean has warmed unabated since 1970 and has taken up more than 90% of the excess heat in the climate system (high confidence). Since 1993, the rate of ocean warming has more than doubled (likely). Marine heatwaves have very likely doubled in frequency since 1982 and are increasing in intensity (very high confidence). By absorbing more CO2, the ocean has undergone increasing surface acidification (virtually certain). A loss of oxygen has occurred from the surface to 1000 m (medium confidence). - Global mean sea level (GMSL) is rising, with acceleration in recent decades due to increasing rates of ice loss from the Greenland and Antarctic ice sheets (very high confidence), as well as continued glacier mass loss and ocean thermal expansion. Increases in tropical cyclone winds and rainfall, and increases in extreme waves, combined with relative sea level rise, exacerbate extreme sea level events and coastal hazards (high confidence). Observed Impacts on Ecosystems: - Cryospheric and associated hydrological changes have impacted terrestrial and freshwater species and ecosystems in high mountain and polar regions through the appearance of land previously covered by ice, changes in snow cover, and thawing permafrost. These changes have contributed to changing the seasonal activities, abundance and distribution of ecologically, culturally, and economically important plant and animal species, ecological disturbances, and ecosystem functioning. (high confidence). - Since about 1950 many marine species across various groups have undergone shifts in geographical range and seasonal activities in response to ocean warming, sea ice change and biogeochemical changes, such as oxygen loss, to their habitats (high confidence). This has resulted in shifts in species composition, abundance and biomass production of ecosystems, from the equator to the poles. Altered interactions between species have caused cascading impacts on ecosystem structure and functioning (medium confidence). In some marine ecosystems species are impacted by both the effects of fishing and climate changes (medium confidence). - Coastal ecosystems are affected by ocean warming, including intensified marine heatwaves, acidification, loss of oxygen, salinity intrusion and sea level rise, in combination with adverse effects from human activities on ocean and land (high confidence). Impacts are already observed on habitat area and biodiversity, as well as ecosystem functioning and services (high confidence). Observed Impacts on People and Ecosystem Services: - Since the mid-20th century, the shrinking cryosphere in the Arctic and high mountain areas has led to predominantly negative impacts on food security, water resources, water quality, livelihoods, health and well-being, infrastructure, transportation, tourism and recreation, as well as culture of human societies, particularly for Indigenous peoples (high confidence). Costs and benefits have been unequally distributed across populations and regions. Adaptation efforts have benefited from the inclusion of Indigenous knowledge and local knowledge (high confidence). - Changes in the ocean have impacted marine ecosystems and ecosystem services with regionally diverse outcomes, challenging their governance (high confidence). Both positive and negative impacts result for food security through fisheries (medium confidence), local cultures and livelihoods (medium confidence), and tourism and recreation (medium confidence). The impacts on ecosystem services have negative consequences for health and well-being (medium confidence), and for Indigenous peoples and local communities dependent on fisheries (high confidence). - Coastal communities are exposed to multiple climate-related hazards, including tropical cyclones, extreme sea levels and flooding, marine heatwaves, sea ice loss, and permafrost thaw (high confidence). A diversity of responses has been implemented worldwide, mostly after extreme events, but also some in anticipation of future sea level rise, e.g., in the case of large infrastructure. Projected Changes and Risks: Projected Physical Changes: - Global-scale glacier mass loss, permafrost thaw, and decline in snow cover and Arctic sea ice extent are projected to continue in the near-term (2031-2050) due to surface air temperature increases (high confidence), with unavoidable consequences for river runoff and local hazards (high confidence). The Greenland and Antarctic Ice Sheets are projected to lose mass at an increasing rate throughout the 21st century and beyond (high confidence). The rates and magnitudes of these cryospheric changes are projected to increase further in the second half of the 21st century in a high greenhouse gas emissions scenario (high confidence). Strong reductions in greenhouse gas emissions in the coming decades are projected to reduce further changes after 2050 (high confidence). - Over the 21st century, the ocean is projected to transition to unprecedented conditions with increased temperatures (virtually certain), greater upper ocean stratification (very likely), further acidification (virtually certain), oxygen decline (medium confidence), and altered net primary production (low confidence). Marine heatwaves (very high confidence) and extreme El Niño and La Niña events (medium confidence) are projected to become more frequent. The Atlantic Meridional Overturning Circulation (AMOC) is projected to weaken (very likely). The rates and magnitudes of these changes will be smaller under scenarios with low greenhouse gas emissions (very likely). - Sea level continues to rise at an increasing rate. Extreme sea level events that are historically rare (once per century in the recent past) are projected to occur frequently (at least once per year) at many locations by 2050 in all RCP scenarios, especially in tropical regions (high confidence). The increasing frequency of high water levels can have severe impacts in many locations depending on exposure (high confidence). Sea level rise is projected to continue beyond 2100 in all RCP scenarios. For a high emissions scenario (RCP8.5), projections of global sea level rise by 2100 are greater than in AR5 due to a larger contribution from the Antarctic Ice Sheet (medium confidence). In coming centuries under RCP8.5, sea level rise is projected to exceed rates of several centimetres per year resulting in multi-metre rise (medium confidence), while for RCP2.6 sea level rise is projected to be limited to around 1 m in 2300 (low confidence). Extreme sea levels and coastal hazards will be exacerbated by projected increases in tropical cyclone intensity and precipitation (high confidence). Projected changes in waves and tides vary locally in whether they amplify or ameliorate these hazards (medium confidence). Projected Risks for Ecosystems: - Future land cryosphere changes will continue to alter terrestrial and freshwater ecosystems in high mountain and polar regions with major shifts in species distributions resulting in changes in ecosystem structure and functioning, and eventual loss of globally unique biodiversity (medium confidence). Wildfire is projected to increase significantly for the rest of this century across most tundra and boreal regions, and also in some mountain regions (medium confidence). - A decrease in global biomass of marine animal communities, their production, and fisheries catch potential, and a shift in species composition are projected over the 21st century in ocean ecosystems from the surface to the deep seafloor under all emission scenarios (medium confidence). The rate and magnitude of decline are projected to be highest in the tropics (high confidence), whereas impacts remain diverse in polar regions (medium confidence) and increase for high emissions scenarios. Ocean acidification (medium confidence), oxygen loss (medium confidence) and reduced sea ice extent (medium confidence) as well as non-climatic human activities (medium confidence) have the potential to exacerbate these warming-induced ecosystem impacts. - Risks of severe impacts on biodiversity, structure and function of coastal ecosystems are projected to be higher for elevated temperatures under high compared to low emissions scenarios in the 21st century and beyond. Projected ecosystem responses include losses of species habitat and diversity, and degradation of ecosystem functions. The capacity of organisms and ecosystems to adjust and adapt is higher at lower emissions scenarios (high confidence). For sensitive ecosystems such as seagrass meadows and kelp forests, high risks are projected if global warming exceeds 2ºC above pre-industrial temperature, combined with other climate-related hazards (high confidence). Warm-water corals are at high risk already and are projected to transition to very high risk even if global warming is limited to 1.5ºC (very high confidence). Projected Risks for People and Ecosystem Services: - Future cryosphere changes on land are projected to affect water resources and their uses, such as hydropower (high confidence) and irrigated agriculture in and downstream of high mountain areas (medium confidence), as well as livelihoods in the Arctic (medium confidence). Changes in floods, avalanches, landslides, and ground destabilization are projected to increase risk for infrastructure, cultural, tourism, and recreational assets (medium confidence). - Future shifts in fish distribution and decreases in their abundance and fisheries catch potential due to climate change are projected to affect income, livelihoods, and food security of marine resource-dependent communities (medium confidence). Long-term loss and degradation of marine ecosystems compromises the ocean's role in cultural, recreational, and intrinsic values important for human identity and well-being (medium confidence). Implementing Responses to Ocean and Cryosphere Change: Challenges: - Impacts of climate-related changes in the ocean and cryosphere increasingly challenge current governance efforts to develop and implement adaptation responses from local to global scales, and in some cases pushing them to their limits. People with the highest exposure and vulnerability are often those with lowest capacity to respond (high confidence). Strengthening Response Options: - The far-reaching services and options provided by ocean and cryosphere-related ecosystems can be supported by protection, restoration, precautionary ecosystem-based management of renewable resource use, and the reduction of pollution and other stressors (high confidence). Integrated water management (medium confidence) and ecosystem-based adaptation (high confidence) approaches lower climate risks locally and provide multiple societal benefits. However, ecological, financial, institutional and governance constraints for such actions exist (high confidence), and in many contexts ecosystem-based adaptation will only be effective under the lowest levels of warming (high confidence). Enabling Conditions: - Enabling climate resilience and sustainable development depends critically on urgent and ambitious emissions reductions coupled with coordinated sustained and increasingly ambitious adaptation actions (very high confidence). Key enablers for implementing effective responses to climate-related changes in the ocean and cryosphere include intensifying cooperation and coordination among governing authorities across spatial scales and planning horizons. Education and climate literacy, monitoring and forecasting, use of all available knowledge sources, sharing of data, information and knowledge, finance, addressing social vulnerability and equity, and institutional support are also essential. Such investments enable capacity-building, social learning, and participation in context-specific adaptation, as well as the negotiation of trade-offs and realisation of co-benefits in reducing short-term risks and building long-term resilience and sustainability. (high confidence). This report reflects the state of science for ocean and cryosphere for low levels of global warming (1.5ºC), as also assessed in earlier IPCC and IPBES reports.

(O'Brien et al., 2007)

Why different interpretations of vulnerability matter in climate change discourses. - manifestations of different discourses and framings of the climate change problem - two differing interpretations, conceptualized here as 'outcome vulnerability' and 'contextual vulnerability' - linked respectively to a scientific framing and a human-security framing - Each framing prioritizes the production of different types of knowledge, and emphasizes different types of policy responses to climate change - studies are seldom explicit about the interpretation that they use - present a diagnostic tool for distinguishing the two interpretations of vulnerability and use this tool to illustrate the practical consequences that interpretations of vulnerability have for climate change policy and responses in Mozambique - the two interpretations are rooted in different discourses and differ fundamentally in their conceptualization of the character and causes of vulnerability, they cannot be integrated into one common framework. - Instead, it should be recognized that the two interpretations represent complementary approaches to the climate change issue - the human-security framing of climate change has been far less visible in formal, international scientific and policy debates, and addressing this imbalance would broaden the scope of adaptation policies 'vulnerability reduction' as a policy objective may be rhetorically non-controversial, but what this means in practice depends on the particular interpretation of vulnerability - Forsyth (2003, p. 191) points out that '[u]nder orthodox approaches to environmental science, vulnerability may be best addressed by mitigating biophysical changes considered the main causes of risk' - These differ from alternative approaches that emphasize reducing vulnerability by also increasing the ability of societies to adapt to such changes (Forsyth, 2003) Adaptation CC - popular, some degree CC is inevitable -'adjustment in ecological, social, or economic systems in response to actual or expected climatic stimuli and their effects or impacts' (Smit and Pilifosova, 2001, p. 881) - interpretation CLIMATE POLICY 84 O'Brien et al. of vulnerability affects the type of adaptation that is promoted, influencing decisions on what, how, and who to fund (Huq and Burton, 2003). - adaptations made in response to to projected CC - urgency on prediction of how will cahnge - involve some combination of decreasing exposure and increasing coping or adaptive capacities, to respond to multiple shocks and transformations. - 'vulnerability to change', where climate hazards and longterm changes represent only part of the profound transformations affecting societies. - allows adaptation to uncertainty - distinguishing characteristic of environmental change and policy (Mitchell and Hulme, 1999; Lempert et al., 2000; Berkhout et al., 2003). - Thus the natural question to ask is whether it is possible to integrate these two interpretations into a comprehensive and formal framework for understanding vulnerability to climate change. - attempts to develop integrative vulnerability frameworks (see Turner et al., 2003; Ionescu et al., 2005; Füssel and Klein, 2006), these frameworks arguably do not integrate the different interpretations, but instead formalize a single interpretation - conceptual blending = change in beliefs and understandings - much more difficult to integrate across discourses that are based on different models of causality - Outcome vulnerability and contextual vulnerability address two different but interrelated questions that reflect two distinct framings of the climate change issue: (1) 'Are humans changing the climate system?' and (2) 'What are the differential implications of climate change for society?' - two different but complementary aspects of climate change - dominance of the scientific framing of climate change has meant that the scope of adaptation policies has been interpreted quite narrowly (Klein et al., 2007) - . Increased attention to the human-security framing of climate change may raise the relevance of climate change to broader communities, and create a greater urgency for understanding the complexities of the Earth system (O'Brien, 2006) - although integration is important for meaningful comparisons of vulnerability assessments (Ionescu et al., 2005), it is perhaps more important to recognize the usefulness of approaching vulnerability from different perspectives.