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Iceland Nature Conservation Association Ocean and climate English summary: Climate affects all life on earth, the resources that we depend upon, the development of our economy and society, our health and well-being. The oceans act as the world’s thermostat, crucially regulating climate (through the transfer of heat), through carbon sequestration, oxygen production and as a water source. Changing climate and CO2 emissions disrupt the ability of oceanic systems to function properly. Climate change has caused sea temperatures to rise while escalating CO2 emissions lead to increasing acidification of ocean waters. These changes directly affect the distribution and stability of marine animal and plant communities, sea levels will rise (as glaciers melt at an accelerated rate and as water volume increases with temperatures) while deep ocean currents may be disrupted and thereby further destabilise current climate patterns. Iceland is one of many countries which is economically dependent upon the marine environment. In particular, Iceland’s territorial waters include a transition zone where the warm waters of the North Atlantic Drift (Gulf Stream) meet with cold currents from the Arctic Ocean; a zone upon which Iceland’s marine fishery thrives. Therefore, disruption of existing marine systems due to climate change will result in an alteration to Iceland’s fishery. Thus, Iceland may be one of the first countries in Europe to be severly effected by climate change. Introduction The world ocean, composed of five interconnected geographical entities (Atlantic, Pacific, Indian, Arctic and Southern Oceans), covers about 71% of the Earth’s surface [1]. Its complex functioning is crucial to all living organisms on the planet [2]. For example, the ocean is the largest net oxygen supplier of the world [3] and plays a key role in the complex mechanism of climatic regulation, consequently influencing many ecosystems [2]. Today, the changing climate is disrupting this climatic balance, having important consequences on the functioning of oceanic processes, and causing major INCA/Náttúruverndarsamtök Ísland Thorunnartun 2 105 Reykjavik unpredictable ecological changes. Despite its crucial role in climate regulation and ecosystem services the ocean has been largely ignored in the debate about climate change. Ø To increase our understanding of the role of the ocean and the threats to it we will explore the following three points: Ø What are the key roles of the ocean? Ø What are the threats to the current functioning of the oceans? And what are the consequences? Ø What are the solutions? e-‐mail: [email protected] Tel: +354 551 2279 Mobile : +354 897 2437 What are the key roles of the oceans? The importance of the ocean for Iceland The ocean acts as the planet's thermostat, playing an essential role in climate regulation, mainly through heat transfer, the carbon pump, oxygen production [4] and water source: The heat transfer function: The heat pump function of the ocean is mainly played by the conveyor belt. In fact, the ocean distributes the heat accumulated in tropical areas to the poles through warm surface currents, thus reducing the temperature differences between these two areas. This is, for example, the role of the Gulf Stream, which allows Iceland to harbor a milder climate in comparison with other areas at the same latitudes. At the poles, these warm surface currents cool down and sink down into the depths from where they return towards the tropics. The change of density is due to the temperature. In fact, the colder water is denser than warm water. This global circulation works like a "conveyor belt" [4]. Since the beginning of the industrial era (19th century), global warming was magnified by the greenhouse gas emissions from anthropogenic activities [5]. The moderating role of the ocean in climate regulation has limited the effect of global warming [6] through its heat storage capacity and through uptake of CO2 gas. In The ocean mechanisms (conveyor belt, Gulf Stream) influence the Icelandic climate and shape the conditions for life in the country. The ocean has always been important for Iceland from the country's settlement to the present time. The ocean is a mode of transport and communication for Iceland. Moreover, a huge part of Iceland's economy depends upon the use of marine resources [14]. It is at the base of the Icelandic industry and economy [15]. For example, fisheries provide a major share of the country’s foreign currency earnings; in 2010, the direct and indirect contribution to GDP was respectively 10.2% and 7.3% [15]. Several other sectors are also concerned: fish processing, aquaculture, tourism (whale watching, nature expeditions, sailing, sport fishing...), biotechnology, manufacturing of gear and equipment (for fishing and fish processing), software production and development (for fishing and fish processing), shipbuilding, transport and service and support industries [14]. fact, the ocean has a heat storage capacity 1000 times greater than that of the atmosphere, [3]. So, since the end 1950's, more than 80% of the accumulated heat excess in the climatic system has been stored in the ocean [7]. Moreover, the ocean has a very important thermal inertia: it heats up and cools down very slowly [3], accentuating its moderator role. The carbon pump function: The ocean plays a crucial role in regulating atmospheric carbon dioxide (CO2) concentration. Since the industrial 2 revolution it has acted as an important sink for CO2, via physicochemical processes and biological activity [8 & 3]. Its carbon storage capacity is roughly 50 times that of the atmosphere [8]. Currently, it has absorbed approximately 26% of total anthropogenic CO2 emissions, roughly 120 billion tons [8 & 9]. The oxygen production function: Between 50 to 85% of the O2 available in the atmosphere originates from the oceans [10]. In fact, tiny marine organisms called phytoplankton or vegetal plankton produce oxygen via photosynthesis. A water source for many ecosystems: The Ocean also contributes to the presence of freshwater on the Earth. Indeed, the ocean contains 97.5% of the Earths water (whereas the continents and the atmosphere contain respectively 2.4% and less than 0.001%) and is the most important reserve of water. Evaporation of water at the sea surface provides the main source of atmospheric water, which is transported inland by wind and subsequent rainfall [3]. events (such as the El Nino or the NorthAtlantic oscillation) to those on much larger time scales (Pleistocene climatic oscillations) [6]. Until now, the ocean has benefited humankind by containing the rising greenhouse gas levels and limiting the increase of temperatures in the atmosphere, thus reducing the impacts of global warming so far. Fifty years ago, the general consensus of the scientific community was that due to the ocean's natural buffering system, anthropogenic addition of CO2 into the atmosphere was unlikely to cause major changes in pH. Today, the scientific community recognizes that this is untrue [16]. In fact, the temperature elevation and the ocean’s uptake of carbon dioxide are modifying the ocean environment to the point provoking direct consequences on marine ecosystems, and other dependent ecosystems, as well as on humans being. The main concern is how much the ocean will continue to absorb heat and CO2 excess produced by human activities? If its absorption capacity suddenly reaches its maximal, will the effect be accelerated rates of global warming and ocean acidification to a point never before considered? Other roles: In addition to regulating the climate, the ocean provides many other ecosystem services1, such as food supply, or still protection against natural hazards. [12]. Scientists estimate that 63% of global ecosystem services are generated by the ocean [13]. Conclusion: Ocean and climate are intimately linked and interact continuously through feedback reactions. The ocean has an effect on climatic phenomenon from short-term 1 The ecosystem services correspond to the benefits people obtain from ecosystems [11]. 3 What are the threats to the current functioning of the oceans? And what are the consequences? The increase in CO2 has mainly two direct effects on the ocean functioning: the increase of water temperature and ocean acidification, causing for example a rise in sea levels and modifications to marine communities. However, it remains still difficult to predict with accuracy the consequences of climate change on ecosystems and humans. Rising temperature: Direct effects on marine species: Studies suggest that the responses of marine species to the ongoing increase in sea temperature will be highly variable, reflecting their different sensitivities. Some species are adapting to this change, others are migrating to colder waters and still others will not adapt quickly enough and will disappear [4]. In consequence, the local abundance, the distribution and genetic diversity of some species are expected to change drastically. This will also have an effect at the community level with change in species composition and modifications of food webs, ultimately affecting interactions between species. The current “balance” within communities is changing and will certainly affect stability of ecosystem services beneficial to human [4]. This change of communities might also be amplified by a localized phenomenon of deoxygenation in seawater (anoxic conditions). The combination of coastal eutrophication and the increase of sea temperature generates local areas with a very low oxygen concentration, called "dead zones". In fact, because the oxygen solubility decreases with the increase of temperature (the warmer the water the less oxygen can be carried) dead zones are mainly located in warmer coastal areas. In the coastal ocean, the number of dead zones has considerably increased since 60's, with 479 areas so far identified (such as the Black Sea, Baltic, Kattegat, Gulf of Mexico and the South China Sea) [3]. These modifications of marine habitats can have direct (e.g. species extinction) or indirect (e.g. through competition for trophic resources or habitat…) impacts on some species of huge economic importance to human. Rising sea level and melting glaciers: Since the beginning of 20th century, measurements have shown that the rise in sea level increased on average to 1.7 mm per year. The forecast for 2100 predicts a faster rate of sea level rise than at present, including between 25cm and 82cm, according to the different scenarios of greenhouse gas emission. This increase is mainly due to thermic distention of the 4 ocean (water expands as it warms) and melting glaciers and polar icecaps (the additional freshwater inflows lead directly to an increase of sea level) [3]. In Iceland, for example, studies estimate that Iceland has been losing about 9.5 billion tons of ice each year since 1995 [17]. Concretely, over the last 10 years, the glaciers have retreated at an average rate of 25 m/year, accelerating to 50m/year over the past 5 years. Within 150 years, all Icelandic glaciers will disappear entirely. The Icelandic glaciers are also sensitive to geothermal activities but only 5% of their melting is attributed to volcanic influences [17]. They act as sentinels of the changes occurring in other glaciers worldwide [18]. The melting glaciers disrupt the ecosystems [3] by changing the hydrographic network. In fact, the flow rate increases and the annexed channels disappear, to be concentrated in one bed, engendering a loss of biodiversity by a loss of habitats. But the most important impact of melting glaciers might be for the oceans [18]. Modification of deep currents In fact, the freshwater input caused by the melting glaciers might decrease the seawater salinity [3] and so the density of the seawater. The difference of density in water layers is the engine of the conveyor belt mechanism. When warm and relatively saline seawater cools as it is transported to higher latitudes, its density increases causing the water mass to sink. This process may be considered the driving force behind the thermohaline circulation. However, melting of sea-ice and glaciers increases the flow of freshwater into the oceans, potentially decreasing the density of surface seawater, which may have negative consequences for its capacity to sink. According to some forecasts, scientists are hypothesizing that the conveyor belt mechanism might slow down or even disappear. In that case, Europe might be subjected to an important cooling caused by the slowing down or the stopping of Gulf Stream [18]. Acidification of the oceans: The ocean’s uptake of carbon dioxide modifies significantly the chemistry of seawater, causing ocean acidification that has direct consequences for marine ecosystems [9]. For example, population sizes of salmon in the North Atlantic and North Pacific are expected to decrease drastically in the next decades because their main food source, the Pteropods (planktonic mollusks), are likely to decrease in abundance due to the effects of ocean acidification on their shells. In fact, the chemical reactions can lead to the dissolving of their shells [3]. The salmon is an important economic resource for many people. Consequently, these modifications of ecological communities might have important consequences for different economic sectors such as fisheries, aquaculture, and tourism... It is still difficult to predict with accuracy the consequences of ocean acidification, but it is certain that marine communities will change. The organisms that are most likely to be affected first are those with calcium carbonate shells or skeletons [9]. The organisms can cope with these changes in two ways: they can acclimatize to them or adapt. But if we continue to emit CO2 at the present level, researchers predict an increase of about 170% of the ocean acidity by 2100[9]. Moreover, the current rate of acidification is more than 10 times faster than any time in the last 55 million years. So, species that are vulnerable to such changes must acclimate or adapt or else they will disappear [9]. 5 Consequences for Iceland Global warming and its consequences on the ocean functioning (rising sea level, acidification, deoxygenation, potential modification of conveyor belt...) particularly affect coastal and insular areas [4]. Iceland is not an exception, even if it should not be impacted like other islands by the rising sea level. In fact, the melting glacier engenders an uplift of the Icelandic crust about 35mm/year [19] while the rising sea level is about 1.7mm/year. However, as we saw, its economy depends strongly upon ocean resources, so we can imagine an important economic loss directly affecting sectors like fisheries or tourism. Furthermore, ocean acidification is a heterogeneous process across the globe. The areas of greater impact are those of cold seawater, as we can find around Iceland [23]. Moreover, in the case whereby the Gulf Stream might be slowed down or stopped, the Icelandic climatic conditions might become rougher and colder similar to those of Greenland at Conclusion: It is difficult to predict with exactitude the effect of global warming on the functioning of the ocean but it is important to take into account the different scenarios in our current decision-making. Humanity will have to cope with a changing climate which will affect coastal populations, industrial activities in the Arctic and the fisheries and aquaculture [3]. Moreover, the loss of marine biodiversity weakens the ocean's ecosystem services, its ability to withstand disruption, to adapt to climate change and to play its climate regulator role [4]. So, it is urgent to maintain the functional quality of these ecosystems and to restore those that are the most degraded. In fact, although the climate machine is already running, it is essential to reduce our impact so as to avoid uncontrollable global warming. What are the solutions? In his address to the Ban Ki-moon climate summit held in September last year, Iceland’s PM, Sigmundur Davíð Gunnlaugsson stated that Recent studies, including by the Arctic Council, suggest that climate change is the most serious threat to Arctic biodiversity and ecosystems, including ocean acidification as Arctic and sub-Arctic waters can be especially vulnerable to acidification, which again can only be stopped by halting carbon emissions. This might seem obvious, the solution is staring us in the eye and yet governments have not risen to the challenge of halting carbon emissions, replacing dirty energy with clean and renewable energy. The upcoming meeting in Paris will provide a one off opportunity to take bring about carbon free future. Chloé Mathieu 6 Bibliography [1] Website NOAA: http://www.noaa.gov/ocean.html [2] Website IRD: https://www.ird.fr/lamediatheque/expositions/expositionsdisponibles-en-pret/ocean-et-climat. [3] Océan et climat, 2015. Fiches scientifiques. www.ocean-climate.org, 106 p. [4] Océan et climat. Les interactions entre l’océan et le climat, 6 fiches d’information. www.ocean-climate.org, 12 p. [5] Website manicore.com: http://www.manicore.com/documentation/serre/a nthropique.html. [6] Website IFREMER: http://www.ifremer.fr/lpo/cours/nao/climat.html. [7] Michaut C., 08/2009. Les dossiers de la recherche n°36. L’océan atténue le réchauffement. [8] Rhein, M., S.R. Rintoul, S. Aoki, E. Campos, D. Chambers, R.A. Feely, S. Gulev, G.C. Johnson, S.A. Josey, A. Kostianoy, C. Mauritzen, D. Roemmich, L.D. Talley and F. Wang, 2013: Observations: Ocean. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V.Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. [9] IGBP, IOC, SCOR (2013). Ocean Acidification Summary for Policymakers – Third Symposium on the Ocean in a High-CO2 World. International Geosphere-Biosphere Programme, Stockholm, Sweden. [10] Website earthsky.org: http://earthsky.org/earth/how-much-do-oceansadd-to-worlds-oxygen. [11] Millennium Ecosystem Assessment (MA). 2005. Ecosystems and Human Well-Being: Synthesis [1]. Island Press, Washington. 155p. [12] UICN France (2013). Panorama des services écologiques fournis par les milieux naturels en France - volume 2.2 : les écosystèmes marins et côtiers. Paris, France. [13] Costanza R, d’Arge R, de Groot R, Farber S, Grasso M, Hannon B, et al. (1997) The value of the world’s ecosystem services and natural capital. Nature 387:253–260. [14] Icelandic Government Policy, 2004.Ocean, Iceland’s policy. 46 p. [15] Íslandsbanki. The Importance of the Ocean Cluster for the Icelandic Economy. [16] Website notreplanete.info: http://www.notreplanete.info/actualites/actu_229 7_oceans_climat.php. [17] Website livescience.com: http://www.livescience.com/49751-icelandrising-melting-ice.html. [18] Radio Canada.ca. Découverte - La fonte des glaciers islandais. Video: https://www.youtube.com/watch?v=SuSn8P9Rrg o. [19] Website sciencedaily.com: http://www.sciencedaily.com/releases/2015/01/1 50129113719.htm. [20] Website askjaenergy.org: http://askjaenergy.org/iceland-‐ introduction/iceland-‐energy-‐sector/. [21] Website ec.europa.eu: http://ec.europa.eu/eurostat/statisticsexplained/index.php/Energy_from_renewable_so urces. [22] Website lemonde.fr: http://oceanclimat.blog.lemonde.fr/2015/08/31/lo cean-grand-absent-de-la-conference-de-paris/ [23] Website les crises.fr: http://www.lescrises.fr/climat-21-consequences-3 7 Ocean and climate French summary: Le climat conditionne la vie sur Terre, les ressources dont nous disposons, le développement de nos sociétés, ou encore notre santé. En fait, l'océan agit comme le thermostat de la planète, jouant un rôle essentiel dans la régulation du climat, principalement de par ses fonctions de transfert de chaleur, de pompe à carbone, de producteur d'oxygène et de source d'eau. Cependant, le réchauffement climatique menace le fonctionnement actuel des océans. En effet, il entraine une acidification et une augmentation accélérée de la température des eaux marines. La modification de ces deux paramètres affecte directement la distribution et la stabilité des communautés marines animales et végétales, augmente le niveau de la mer (via l’accélération de la fonte des calottes glaciaires et la dilatation de l’eau) et pourrait ainsi modifier les grands courants océaniques planétaires responsables du climat actuel. Certains pays comme l’Islande sont économiquement dépendant de l'océan. Le premier secteur économique, la pêche, dépend directement de la rencontre de courant océanique chaud (Gulf Stream) et froid dont la stabilité pourrait être remise en cause par le réchauffement climatique global. Ainsi, L’Islande sera l’un des premiers pays impactés par ces changements. Que pouvons-nous faire face à ce problème ? Réduire rapidement et drastiquement nos émissions de gaz à effet de serre en 1) faisant prendre conscience à chacun la responsabilité qui lui incombe dans l’émission de gaz à effet de serre due à son mode de vie, 2) en lançant une campagne interventionniste des états à l’échelle internationale auprès de l’ensemble des secteurs économiques en fixant des règles communes pour imposer l’utilisation des technologies existantes les plus efficaces, 3) en investissant massivement dans la recherche et le développement ainsi que la mise en place des multiple formes d’énergies renouvelables prenant en compte les contextes locaux. 4) en intégrant l'océan dans les discussions internationales comme l’acteur majeur de la régulation climatique et socio-économiques de la planète. 5) en augmentant le budget pour le financement d’études scientifiques indépendantes afin d'améliorer notre compréhension des conséquences de ces changements sur le fonctionnement de l’océan et des écosystèmes dans le but de fournir des mesures de protection / restauration adéquates. French introduction: L’océan mondial, composé de cinq entités géographiques interconnectées (Atlantique, Pacifique, Indien, Arctique et du Sud), couvre environ 71% de la surface de la Terre [1]. Son fonctionnement complexe est vital pour l’ensemble des êtres vivants [2]. Par exemple, l'océan est le plus grand fournisseur d'oxygène du monde [3]. De plus, il joue un rôle clé dans le mécanisme complexe de la régulation climatique; influençant par conséquent de nombreux écosystèmes et l’équilibre socio-économique actuel [2]. Aujourd’hui le réchauffement climatique global perturbe l’équilibre climatique engendrant ainsi d’importantes conséquences sur le fonctionnement des océans, et provoquant des changements écologiques majeurs difficilement prévisibles. Afin de mieux comprendre le rôle de l'océan et les menaces qui pèsent sur lui, nous développerons les trois points suivants: Ø Quels sont les rôles clés de l'océan? Ø Quelles sont les menaces qui pèsent sur le fonctionnement actuel des océans? Et quelles en sont les conséquences ? Ø Quelles sont les solutions? 8