8. Global scale pressures on reefs—climate change

Author(s):  
Charles Sheppard

Ocean temperatures are rising. This is critical for corals and other reef organisms because most live very close to their thermal limits already. The rise is caused by the greenhouse effect from increasing CO2 emissions. Superimposed on a general background rise caused by the general increase in heat content of the world are pulses—ocean heatwaves—caused by vagaries in ocean circulation. Globally, this is now the greatest threat to reefs. Warming pulses cause mass coral bleaching and mortality when the overstressed symbiotic algae are expelled from the corals, showing the white limestone beneath the now transparent coral tissue. All coral reef areas of the world now exhibit mass bleaching events. Recovery of a reef is possible, but only if given some decades of stable temperatures, and predictions are that warming events are occurring increasingly frequently and are of increasing severity. Coral cover on reefs in all reef areas is declining sharply. Seawater also becomes increasingly acidic, which impedes coral calcification. Added to this, there is a lag of 20–40 years for carbon dioxide in the air to equilibrate with the ocean, so even were there to be a cessation in the rise in the atmosphere today, these effects would continue to develop for a few decades more. 350 parts per million CO2 is considered to be a threshold concentration for calcification to be possible but already the atmosphere is at about 415 ppm. Sea levels are rising too as a result, and reefs are degrading and losing their ability to act as breakwaters.

2021 ◽  
Vol 2 (3) ◽  
pp. 247-256

Összefoglaló. A második világháborút követően talán nem volt egyetlen esemény sem, amely olyan hatást gyakorolt a világ országaira, mint a koronavírus-járvány kirobbanása. A vírus-válság felgyorsította a liberális világrend erózióját, kiélezte a nagyhatalmak közötti ellentéteket, válságforgatókönyvek és prognózisok készültek. A válság rávilágított arra is, hogy kudarcra vannak ítélve azok a kormányzatok, amelyek nem ruháztak be a közösségi infrastruktúrába, és elhanyagolták a közszolgálati tudást. Az is kiderült, hogy a kormányzati intézményeknek szakértőkre és nem lojális mamelukokra van szüksége a válsághelyzetből fakadó közpolitikai gondok megoldása során. Egy világméretű és példátlan sebességgel terjedő válság elleni eredményes fellépés elsődleges frontvonala tehát a nemzetállam maradt. Summary. In times of crisis, all political systems give the executive exceptional powers, as it is not possible to face new and rapidly changing challenges within the framework of existing laws. One of the American founding fathers, Alexander Hamilton, who feared the excessive power of central government, believed that in times of emergency the system of checks and balances should be suspended. Constitutional democracy will be threatened if the rule of law is not restored after the emergency has passed. Perhaps no event since the Second World War has had such an impact on the countries of the world as the outbreak of the coronavirus epidemic. The virus crisis accelerated the erosion of the liberal world order, sharpened the antagonism between the great powers, especially the US and China, and highlighted the vulnerability of the production chains that had been outsourced to the Far East in the hope of cheap labour. Crisis scenarios and forecasts were drawn up, and prominent scientists and researchers expressed the view that there would be no return to the world before the virus. The virus crisis has also highlighted the failure of governments that have not invested in community infrastructure and have neglected public knowledge. It has also shown that government institutions need experts, not loyal mamelukes, to solve public policy problems arising from the crisis. The coronavirus is the most pressing challenge of this century so far, and in responding to it, localism is being valorised as a crucial centre of solidarity and problem-solving. Forecasters fear that rising inequalities and the erosion of family savings could trigger a wave of political discontent that is more angry and violent than ever before. The majority of people will not be able to manage their children’s digital education and work from home without a separate room and computing infrastructure, so governments will need to develop special programmes to address this, and people’s health and the capacity of public health to cope will come to the fore. The pandemic crisis has provided a new argument for those who argued for the reinvention of the state and the importance of governments’ ability to act quickly to deal effectively with natural and economic crises. In recent decades, many have buried the nation state, arguing that successful responses to global problems in a globalised world cannot be found within the framework of a nation state. The Covid-19 crisis has shown that the nation state remains the first front line for effective action against a crisis that is spreading at an unprecedented global scale and speed. Different countries have followed different crisis management strategies and very significant differences in contagion rates have emerged. The crisis has reassessed the role of nation states and borders, which already played an important role in receiving migration flows.


2020 ◽  
pp. 016224392094993
Author(s):  
Jessica Lehman

The ability to quantify the relationship between the ocean and the atmosphere is an enduring challenge for global-scale science. This paper analyzes the World Ocean Circulation Experiment (WOCE, 1990–2002), an international oceanographic program that aimed to provide data for decadal-scale climate modeling and for the first time produce a “snapshot” of ocean circulation against which future change could be measured. WOCE was an ambitious project that drew on extensive international collaboration and emerging technologies that continue to play a significant role in how the global environment is known and governed. However, a main outcome of WOCE was an encounter with ocean variability: the notion that the ocean is governed not by the circular currents shown in the popular “conveyor-belt” diagram but by eddies, filaments, jets, and other nonlinear forces. This paper suggests the concept of “productive limits” as an analytic for understanding how ocean variability both prompted new forms of knowledge and the development of a global knowledge infrastructure that is contingent, uneven, and fully entwined with geopolitical dynamics.


2019 ◽  
Vol 47 (3) ◽  
pp. 80-91
Author(s):  
V. G. Neiman

The main content of the work consists of certain systematization and addition of longexisting, but eventually deformed and partly lost qualitative ideas about the role of thermal and wind factors that determine the physical mechanism of the World Ocean’s General Circulation System (OGCS). It is noted that the conceptual foundations of the theory of the OGCS in one form or another are contained in the works of many well-known hydrophysicists of the last century, but the aggregate, logically coherent description of the key factors determining the physical model of the OGCS in the public literature is not so easy to find. An attempt is made to clarify and concretize some general ideas about the two key blocks that form the basis of an adequate physical model of the system of oceanic water masses motion in a climatic scale. Attention is drawn to the fact that when analyzing the OGCS it is necessary to take into account not only immediate but also indirect effects of thermal and wind factors on the ocean surface. In conclusion, it is noted that, in the end, by the uneven flow of heat to the surface of the ocean can be explained the nature of both external and almost all internal factors, in one way or another contributing to the excitation of the general, or climatic, ocean circulation.


2020 ◽  
Author(s):  
Johann Johann And Devika

BACKGROUND Since November 2019, Covid - 19 has spread across the globe costing people their lives and countries their economic stability. The world has become more interconnected over the past few decades owing to globalisation and such pandemics as the Covid -19 are cons of that. This paper attempts to gain deeper understanding into the correlation between globalisation and pandemics. It is a descriptive analysis on how one of the factors that was responsible for the spread of this virus on a global scale is globalisation. OBJECTIVE - To understand the close relationship that globalisation and pandemics share. - To understand the scale of the spread of viruses on a global scale though a comparison between SARS and Covid -19. - To understand the sale of globalisation present during SARS and Covid - 19. METHODS A descriptive qualitative comparative analysis was used throughout this research. RESULTS Globalisation does play a significant role in the spread of pandemics on a global level. CONCLUSIONS - SARS and Covid - 19 were varied in terms of severity and spread. - The scale of globalisation was different during the time of SARS and Covid - 19. - Globalisation can be the reason for the faster spread in Pandemics.


2021 ◽  
pp. 1-16
Author(s):  
Alessandra GUIDA

The international trade in biotech products boosts national economies and advances scientific as well as technology innovation. However, while trading these products increases the spread of benefits on a global scale, it also increases risks to human health and the environment (ie biosafety). This is because the effects of this technology on biosafety are still highly uncertain. Against this background, the judicial bodies under the World Trade Organization (WTO) find themselves in the middle of an intricate and polarised debate in which a proper judicial balance between free trade and biosafety becomes fundamental in order to determine whether requests for ensuring human and environmental health justify trade restrictions. This paper aims to highlight that the WTO is institutionally unready for balancing economic and non-economic values. In suggesting how to rationalise the judicial balance between the competing interests in the context of biotechnology, this paper demonstrates that the judicial adoption of a well-structured proportionality analysis can turn the current balance by chance into a balance by structure.


2021 ◽  
Vol 13 (6) ◽  
pp. 1051
Author(s):  
Cecile S. Rousseaux ◽  
Watson W. Gregg ◽  
Lesley Ott

While forecasts of atmospheric variables, and to a lesser degree ocean circulation, are relatively common, the forecast of biogeochemical conditions is still in its infancy. Using a dynamical ocean biogeochemical forecast forced by seasonal forecasts of atmospheric and physical ocean variables, we produce seasonal predictions of chlorophyll concentration at the global scale. Results show significant Anomaly Correlation Coefficients (ACCs) for the majority of regions (11 out of the 12 regions for the 1-month lead forecast). Root mean square errors are smaller (<0.05 µg chlorophyll (chl) L−1) in the Equatorial regions compared to the higher latitudes (range from 0.05 up to 0.13 µg chl L−1). The forecast for all regions except three (North Atlantic, South Pacific and North Indian) are within the Semi-Interquartile Range of the satellite chlorophyll concentration (Suomi-National Polar-orbiting Partnership (NPP), 27.9%). This suggests the potential for skillful global biogeochemical forecasts on seasonal timescales of chlorophyll, primary production and harmful algal blooms that could support fisheries management and other applications.


Author(s):  
Mauricio Onetto Pavez

The year 2020 marks the five hundredth anniversary of the “discovery” of the Strait of Magellan. The unveiling of this passage between 1519 and 1522 allowed the planet to be circumnavigated for the first time in the history of humanity. All maritime routes could now be connected, and the idea of the Earth, in its geographical, cosmographic, and philosophical dimensions, gained its definitive meaning. This discovery can be considered one of the founding events of the modern world and of the process of globalization that still continues today. This new connectivity awoke an immediate interest in Europe that led to the emergence of a political consciousness of possession, domination, and territorial occupation generalized on a global scale, and the American continent was the starting point for this. This consciousness also inspired a desire for knowledge about this new form of inhabiting the world. Various fields of knowledge were redefined thanks to the new spaces and measurements produced by the discovery of the southern part of the Americas, which was recorded in books on cosmography, natural history, cartography, and manuscripts, circulating mainly between the Americas and Europe. All these processes transformed the Strait of Magellan into a geopolitical space coveted by Europeans during the 16th century. As an interoceanic connector, it was used to imagine commercial routes to the Orient and political projects that could sustain these dynamics. It was also conceived as a space to speculate on the potential wealth in the extreme south of the continent. In addition, on the Spanish side, some agents of the Crown considered it a strategic place for imperial projections and the defense of the Americas.


2002 ◽  
Vol 2 ◽  
pp. 827-841 ◽  
Author(s):  
Michael Bredemeier

The focus in this review of long-term effects on forest ecosystems is on human impact. As a classification of this differentiated and complex matter, three domains of long-term effects with different scales in space and time are distinguished: 1- Exploitation and conversion history of forests in areas of extended human settlement 2- Long-range air pollution and acid deposition in industrialized regions 3- Current global loss of forests and soil degradation.There is an evident link between the first and the third point in the list. Cultivation of primary forestland — with its tremendous effects on land cover — took place in Europe many centuries ago and continued for centuries. Deforestation today is a phenomenon predominantly observed in the developing countries, yet it threatens biotic and soil resources on a global scale. Acidification of forest soils caused by long-range air pollution from anthropogenic emission sources is a regional to continental problem in industrialized parts of the world. As a result of emission reduction legislation, atmospheric acid deposition is currently on the retreat in the richer industrialized regions (e.g., Europe, U.S., Japan); however, because many other regions of the world are at present rapidly developing their polluting industries (e.g., China and India), “acid rain” will most probably remain a serious ecological problem on regional scales. It is believed to have caused considerable destabilization of forest ecosystems, adding to the strong structural and biogeochemical impacts resulting from exploitation history.Deforestation and soil degradation cause the most pressing ecological problems for the time being, at least on the global scale. In many of those regions where loss of forests and soils is now high, it may be extremely difficult or impossible to restore forest ecosystems and soil productivity. Moreover, the driving forces, which are predominantly of a demographic and socioeconomic nature, do not yet seem to be lessening in strength. It can only be hoped that a wise policy of international cooperation and shared aims can cope with this problem in the future.


2015 ◽  
Vol 12 (5) ◽  
pp. 1339-1356 ◽  
Author(s):  
N. S. Jones ◽  
A. Ridgwell ◽  
E. J. Hendy

Abstract. Calcification by coral reef communities is estimated to account for half of all carbonate produced in shallow water environments and more than 25% of the total carbonate buried in marine sediments globally. Production of calcium carbonate by coral reefs is therefore an important component of the global carbon cycle; it is also threatened by future global warming and other global change pressures. Numerical models of reefal carbonate production are needed for understanding how carbonate deposition responds to environmental conditions including atmospheric CO2 concentrations in the past and into the future. However, before any projections can be made, the basic test is to establish model skill in recreating present-day calcification rates. Here we evaluate four published model descriptions of reef carbonate production in terms of their predictive power, at both local and global scales. We also compile available global data on reef calcification to produce an independent observation-based data set for the model evaluation of carbonate budget outputs. The four calcification models are based on functions sensitive to combinations of light availability, aragonite saturation (Ωa) and temperature and were implemented within a specifically developed global framework, the Global Reef Accretion Model (GRAM). No model was able to reproduce independent rate estimates of whole-reef calcification, and the output from the temperature-only based approach was the only model to significantly correlate with coral-calcification rate observations. The absence of any predictive power for whole reef systems, even when consistent at the scale of individual corals, points to the overriding importance of coral cover estimates in the calculations. Our work highlights the need for an ecosystem modelling approach, accounting for population dynamics in terms of mortality and recruitment and hence calcifier abundance, in estimating global reef carbonate budgets. In addition, validation of reef carbonate budgets is severely hampered by limited and inconsistent methodology in reef-scale observations.


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