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UN Intergovernmental Panel on Climate Change (IPCC) Special report on Oceans - FAO’s response


The increased momentum on ocean issues within the United Nations Framework Convention on Climate Change (UNFCCC) led to the commissioning of the Intergovernmental Panel on Climate Change (IPCC) Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC) that has been released this week.

FAO welcomes the publication of the SROCC as a key milestone in the knowledge of climate change impacts on oceans and seas, and a valuable guide for the Organization’s future work on ocean-related food production and relative socio-economic implications, in the context of climate change.

The report confirms the multi-decadal trend of ocean warming, in both surface (0-700m) and deeper layers (700-2000m). There has been an acceleration in the ocean uptake of atmospheric heat and CO2 over the last decade, with consequences on water temperature, oxygen content and pH. Frequency and intensity of climate-related hazards such as tropical cyclones and marine heatwaves continues to increase along with a poleward shift of extreme events. Moreover, ice and glacier melting at global scale have resulted in global mean sea level rise at a rate that has tripled over the last century.

The SROCC singles out the fisheries and aquaculture sector as one of the human activities exposed and vulnerable to climate drivers and analyses impacts and responses, echoing the most relevant messages of the FAO Technical Paper 627 on impacts of climate change impacts on fisheries and aquaculture – synthesis of knowledge, adaptation and mitigation options. “The impacts of climate change on the fisheries and aquaculture sector will largely be determined by the sector’s ability to develop and implement adaptation strategies. Successful adaptations could lead to a future with higher profits and yields but failing to adapt will have very negative consequences for the sector” FAO Director of the Fisheries and Aquaculture Policy and Resources Division, Manuel Barange, a review editor for Chapter 5 of the IPCC report, said.

Implications for specific habitats of relevance to fisheries and aquaculture are described in the SROCC. For example, coral reefs, essential for food security in tropical areas, are experiencing significant impacts, affecting their capacity to sustain fisheries. However, even if slow and not always effective, recovery of coral reefs has been observed. In the Eastern Pacific Ocean, Caribbean, Red Sea, Persian Gulf and Great Barrier Reef the recovery has been more rapid than the global average after bleaching.

The report refers to the increased risk of harmful algal blooms (HABs) proliferation in coastal ecosystems and in estuaries in particular, resulting from a combination of climatic and non-climatic drivers such as eutrophication and pollution. The associated risk for natural and human systems are projected to increase, calling for more local scale monitoring programs and enhanced early warning systems to reduce the food safety risk. Moreover, even with low confidence, the report suggests that reducing pollution by nutrient inputs from human sources could reduce the risk of occurrence of HABs.

Deep sea oceans are also experiencing an increase in temperature and a decrease in oxygen and pH. The SROCC frequently refers to FAO’s work, concluding that while some large predators might benefit from the expected changes (e.g. the giant squid will have more easy access to its prey because of the expansion of the minimum oxygen zone), trophic efficiency of food webs and carbon transfer are expected to be negatively impacted. The report identifies a large number of knowledge gaps and uncertainties regarding the trend of catches of deep sea commercial species.

Interestingly, the SROCC provides insight on recent knowledge on genetic and phenotypic plasticity of marine organisms (including commercial species). Some species show higher thermal tolerance than others and may be favoured, noting that there are limits to such natural adaptation with differences among species and populations and that there is still a knowledge gap on thermal critical thresholds.

The combined effects of climate stressors are expected to shape the maximum fish catch potential with patterns that are consistent with the findings of the FAO Technical paper 627, and to alter trophic relationships as well as the resulting relative abundance of large-sized fish (predators) vs. small-sized fish (forage fish). Tropical oceans are expected to undergo larger impacts than the global average, in particular central Pacific, Eastern central Atlantic and Western Indian Ocean, even though some species may show a higher resilience (e.g. skipjack tuna in the Pacific). Winners in terms of catch potential correspond to areas where food security is not under significant threat (e.g. Arctic). The catchability of some species (tuna, thornyheads, dover sole, giant squid) might increase as a result of the expansion of the oxygen minimum zone and the consequent shrinking of suitable habitats. However, the report notes that actual (realized) catches in the 21st century will depend on fishing practices and fisheries governance much more than on climate change impacts alone.

In some Western and Central Pacific island states, Small Scale Fisheries' harvests are projected to decrease by 20 to 50% by 2050 (RCP 2.6 and 8.5) and overall, economic implications of climate change on fisheries is negative in countries with low Human Development Index and is projected to be higher for tropical countries. As stated in the FAO Technical Paper SROCC reiterates the fact that climate change worsens non-climatic socio-economic shocks and stresses and is an obstacle to economic development.

The redistribution of fisheries resources in response to direct and indirect effects of climate change have the potential to have governance implications. Disputes and disagreements in international fisheries management have already occurred (North Atlantic mackerel, Pacific salmon) and are expected to intensify. New fishing opportunities are also arising and the number of transboundary stocks is expected to increase (46 to 60 new shared stocks in 2060 relative to 1950-2014). Appropriate responses are needed to minimize conflicts around resource allocation and management and seize the opportunity to sustainably manage these emerging fisheries. The SROCC highlights that “overfishing is the most important non-climatic driver affecting the sustainability of fisheries”. It also indicates that compared to a no adaptation scenario, sound fisheries adaptation addressing species distribution shifts and rebuilding overexploited or depleted stocks could lead to an increase in global profits (154%), harvest (34%), and biomass (60%) in the future.

The SROCC emphasizes institutional adaptation, highlights the importance of Ecosystem-based Adaptation, the use of Marine Protected Areas as adaptation measures and proposes a specific adaptation framework for seal level rise (protect, accommodate, advance, retreat). However, it does underline the lack of agreement about the cost and long-term effectiveness of ecosystem-based solutions. It advocates for participatory decision-making approaches for fisheries management to address climate change impacts, the use of traditional knowledge and the inclusion of other sectors to foster adaptation. These principles recall those of the Ecosystem Approach to Fisheries and Aquaculture (EAF and EAA) advocated for by FAO over the last decades. However, the adaptation framework described in the FAO Technical Paper 627 offers a broader set of adaptation measures and tools that encompass those described in the SROCC and are relevant for different scales and contexts. It is to be noted that the FAO toolbox also refers to safety at sea of fish workers who are at the forefront of weather events that add to the risks of what is considered the world’s most dangerous occupation.

Adaptation strategies must include institutional and management adaptations, measures addressing livelihoods and, measures intended to manage and mitigate risks and thereby strengthen resilience. Adaptation solutions need political commitment, stakeholder participation, technological innovation and behavioural change to succeed.

The current programme of work of FAO in Chile, Eastern Caribbean, Benguela, Mediterranean, Myanmar, the Philippines,  Cambodia, Timor-Leste, aims at implementing these adaptation tools and measures through extensive field work in order to identify the most suitable responses in every fishery/region. This is expected to contribute filling in some of the gaps mentioned in the SROCC that highlights the lack of examples on governance adaptation in various social and ecological contexts. FAO field programme also looks into the factors that foster adaptation and those that hinder it, while carefully paying attention to minimizing risks of mal-adaptation.

Overall, the SROCC findings and conclusions strongly restate the current and future climate change-related challenges for fisheries and aquaculture-dependent communities, but it also highlights opportunities for changing institutions, exploitation patterns and management practices. Projection results for worse case scenarios suggest that without immediate action, there may be very significant consequences in terms of food security, poverty and human and ecosystem health. On the contrary, if action is taken now, both within and without the fisheries and aquaculture sector, there are significant chances to successfully cope with the changes ahead. Fisheries and aquaculture management authorities need to be encouraged to improve their performance by adjusting their decisions to the anticipated changes as part of a winning strategy towards sustainability.

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