Ocean temperatures are rising, causing increased coral bleaching events, disease, and mortality. If greenhouse gas emissions are not reduced, ocean temperatures are projected to increase by 1.8-4°C by 2100, exceeding the tolerance of many coral species. Increasing temperatures, ocean acidification, sea level rise, and extreme weather events from climate change threaten widespread damage and decline of coral reef ecosystems. Immediate reductions in greenhouse gas emissions, especially CO2, are needed to avoid pushing coral reefs past critical environmental tipping points that could lead to ecosystem collapse.
IMPACTS OF GLOBAL CLIMATE CHANGE ON AQUATIC BIOTAAlbert Wandera
the Presentation discuss the relevant mitigation and adaptation measures which should be employed to address the impacts of Global climatic changes on marine and fresh water habitats and Biota
Global Warming and Marine ecosystems Seminar talkAprili18
Adapted from Article:
"Projecting global marine biodiversity impacts under climate change scenarios" by William W.L. Cheung1, Vicky W.Y. Lam1, Jorge L. Sarmiento2, Kelly Kearney2, Reg Watson1 & Daniel Pauly1
IMPACTS OF GLOBAL CLIMATE CHANGE ON AQUATIC BIOTAAlbert Wandera
the Presentation discuss the relevant mitigation and adaptation measures which should be employed to address the impacts of Global climatic changes on marine and fresh water habitats and Biota
Global Warming and Marine ecosystems Seminar talkAprili18
Adapted from Article:
"Projecting global marine biodiversity impacts under climate change scenarios" by William W.L. Cheung1, Vicky W.Y. Lam1, Jorge L. Sarmiento2, Kelly Kearney2, Reg Watson1 & Daniel Pauly1
Scott Doney's Ocean Acidification presentation, April 2013 Hourglass BrasserieEatingwiththeEcosystem
Dr. Scott Doney from Woods Hole Oceanographic Institution joined a group of guests at the Hourglass Brasserie, Bristol RI, in April 2013 to offer some thoughts on the effects of ocean acidification on New England's treasured seafood.
IMPACT OF GLOBAL WARMING ON AQUATIC FLORA AND FAUNAMahendra Pal
A rise in temperature as small as 1° C could have important and rapid effects on the geographical distributions and mortality of some organisms. The more mobile species should be able to adjust their ranges over time, but less mobile and sedentary species may not.There are many factors that can cause a warming of our climate; for example, more energy from the sun, large natural events such as El Nino or an increased greenhouse effect. Rising temperatures can directly affect the metabolism, life cycle, and behaviour of marine species. For many species, temperature serves as a cue for reproduction. Clearly, changes in sea temperature could affect their successful breeding. The number of male and female offspring is determined by temperature for marine turtles, as well as some fish and copepods (tiny shrimp-like animals on which many other marine animals feed). Changing climate could therefore skew sex ratios and threaten population survival.
An overview of climate change effects potentially impacting the Southeastern United States. Provides references, image credits, and supporting citations in "slide notes" view. For more climate change information, visit the National Biological Information Infrastructure (NBII), Southeast Information Node Climate Change Web site at http://go.usa.gov/OIs
Impacts of Climate Change in Coastal Aquaculture in Bangladeshihn FreeStyle Corp.
Climate change is a change in the statistical distribution of weather over periods of time that range from decades to millions of years. It can be a change in the average weather or a change in the distribution of weather events around an average. Climate change may be limited to a specific region, or may occur across the whole Earth. Climate change may be qualified as anthropogenic climate change, more generally known as "global warming" or "anthropogenic global warming”. Climate change has both direct and indirect impacts on fish stocks which are exploited commercially. Direct effects act on physiology and behavior and alter growth, reproductive capacity, mortality and distribution. Indirect effects alter the productivity, structure and composition of the marine ecosystems on which fish depend for food. However, even though the year-on-year rate of anthropogenic climate change may seem slow, this is very rapid compared with previous natural change and the accumulative value produces a significant difference from the "natural" state quite quickly. Climate change impacts such as more frequent and severe floods and droughts will affect the food and water security of many people.
Bangladesh is thought to be one of the most vulnerable countries of the world to climate change and sea level rise (CCSLR). IPCC estimates predict that due to the impact of climate change, sea level in Bangladesh may rise by 14 cm by 2025, 32cm by 2050 and 88 cm by 2100. There are a number of environmental issues and problems that are hindering development of Bangladesh. Salinity is a current problem, which is expected to exacerbate by climate change and sea level rise. Salinity intrusion due to reduction of freshwater flow from upstream, salinization of groundwater and fluctuation of soil salinity are major concern of Bangladesh. Cyclones and tidal surge is adding to the problem. Tidal surge brings in saline water inside the polders in the coastal area. Due to drainage congestion, the area remains waterlogged, increasing the salinity (Abedin, 2010).
Bangladesh in general is highly vulnerable to predicted climate changes that are already occurring and are expected to continue over the next century. Bangladesh is recognized worldwide as one of the most vulnerable to the impact of global warming and climate change.
Tropical coral reefs cover an area of over 284 000 km2, providing habitat for thousands of species and yielding more than US$ 30 billion annually in global goods and services, such as coastline protection, tourism and food. Corals reefs are now threatened by the increasing concentrations of carbon dioxide in the atmosphere, while warmer sea temperatures are disturbing the delicate symbiosis between coral organisms and algae. For example, 16 per cent of all tropical coral reefs were killed off by thermal stress during a single extreme El Niño–Southern Oscillation event in 1997–1998. As a result of escalating atmospheric levels of carbon dioxide, more of this gas is being dissolved in the world’s oceans. This has already reduced ocean pH and the trend is projected to continue. Moreover, the altered ocean chemistry is expected to have major corrosive effects on marine ecosystems and to alter the calcification rates of corals, phytoplankton and other species.
Scott Doney's Ocean Acidification presentation, April 2013 Hourglass BrasserieEatingwiththeEcosystem
Dr. Scott Doney from Woods Hole Oceanographic Institution joined a group of guests at the Hourglass Brasserie, Bristol RI, in April 2013 to offer some thoughts on the effects of ocean acidification on New England's treasured seafood.
IMPACT OF GLOBAL WARMING ON AQUATIC FLORA AND FAUNAMahendra Pal
A rise in temperature as small as 1° C could have important and rapid effects on the geographical distributions and mortality of some organisms. The more mobile species should be able to adjust their ranges over time, but less mobile and sedentary species may not.There are many factors that can cause a warming of our climate; for example, more energy from the sun, large natural events such as El Nino or an increased greenhouse effect. Rising temperatures can directly affect the metabolism, life cycle, and behaviour of marine species. For many species, temperature serves as a cue for reproduction. Clearly, changes in sea temperature could affect their successful breeding. The number of male and female offspring is determined by temperature for marine turtles, as well as some fish and copepods (tiny shrimp-like animals on which many other marine animals feed). Changing climate could therefore skew sex ratios and threaten population survival.
An overview of climate change effects potentially impacting the Southeastern United States. Provides references, image credits, and supporting citations in "slide notes" view. For more climate change information, visit the National Biological Information Infrastructure (NBII), Southeast Information Node Climate Change Web site at http://go.usa.gov/OIs
Impacts of Climate Change in Coastal Aquaculture in Bangladeshihn FreeStyle Corp.
Climate change is a change in the statistical distribution of weather over periods of time that range from decades to millions of years. It can be a change in the average weather or a change in the distribution of weather events around an average. Climate change may be limited to a specific region, or may occur across the whole Earth. Climate change may be qualified as anthropogenic climate change, more generally known as "global warming" or "anthropogenic global warming”. Climate change has both direct and indirect impacts on fish stocks which are exploited commercially. Direct effects act on physiology and behavior and alter growth, reproductive capacity, mortality and distribution. Indirect effects alter the productivity, structure and composition of the marine ecosystems on which fish depend for food. However, even though the year-on-year rate of anthropogenic climate change may seem slow, this is very rapid compared with previous natural change and the accumulative value produces a significant difference from the "natural" state quite quickly. Climate change impacts such as more frequent and severe floods and droughts will affect the food and water security of many people.
Bangladesh is thought to be one of the most vulnerable countries of the world to climate change and sea level rise (CCSLR). IPCC estimates predict that due to the impact of climate change, sea level in Bangladesh may rise by 14 cm by 2025, 32cm by 2050 and 88 cm by 2100. There are a number of environmental issues and problems that are hindering development of Bangladesh. Salinity is a current problem, which is expected to exacerbate by climate change and sea level rise. Salinity intrusion due to reduction of freshwater flow from upstream, salinization of groundwater and fluctuation of soil salinity are major concern of Bangladesh. Cyclones and tidal surge is adding to the problem. Tidal surge brings in saline water inside the polders in the coastal area. Due to drainage congestion, the area remains waterlogged, increasing the salinity (Abedin, 2010).
Bangladesh in general is highly vulnerable to predicted climate changes that are already occurring and are expected to continue over the next century. Bangladesh is recognized worldwide as one of the most vulnerable to the impact of global warming and climate change.
Tropical coral reefs cover an area of over 284 000 km2, providing habitat for thousands of species and yielding more than US$ 30 billion annually in global goods and services, such as coastline protection, tourism and food. Corals reefs are now threatened by the increasing concentrations of carbon dioxide in the atmosphere, while warmer sea temperatures are disturbing the delicate symbiosis between coral organisms and algae. For example, 16 per cent of all tropical coral reefs were killed off by thermal stress during a single extreme El Niño–Southern Oscillation event in 1997–1998. As a result of escalating atmospheric levels of carbon dioxide, more of this gas is being dissolved in the world’s oceans. This has already reduced ocean pH and the trend is projected to continue. Moreover, the altered ocean chemistry is expected to have major corrosive effects on marine ecosystems and to alter the calcification rates of corals, phytoplankton and other species.
It is our HSS (Humanities and Social Sciences) project.
This document describes how greatly our environment and social life is effected from Global Warming. It describes various perspectives also.
Another high-quality presentation about climate change in Houston, by the venerable Dr. Ronald L. Sass, Professor Emeritus Rice University. Like most academic treatments of the topics covered, only that known with high certainty is reported. There are far more uncertainties that science has not yet pinned down, but that empirical investigations of the past have shown to be worrisome, potentially catastrophic for coastal civilization within a human lifetime. The reader is left to other sources and to their own developing understanding of the immense complexities of rapid climate feedback interactions to imagine the meaning to Houston of the topic covered by Dr. Sass at the conference. Still, an excellent and authoritative place for Houston to begin!
Climate change ,adaptation and mitigation in fisheriesSWAGATIKA SAHOO
Climate change impacts on aquatic and marine ecosystems and associated livelihoods are growing, and the purpose of this circular is to provide a brief overview of potential impacts and details of ongoing and completed adaptation activities. Sharing examples will aid planning and development of adaptation in fisheries and aquaculture, and this compilation is intended to provide a starting point for planners, policy-makers, and practitioners who are involved in sectors related to fisheries and aquaculture around the globe. This introduction provides an overview of climate change impacts on fisheries and aquaculture. The presentation reviews potential mitigation and adaptation options for fisheries and aquaculture at various scales. This is followed by an overview of selected adaptation activities at various scales to demonstrate the types of activities underway or completed around the world, primarily in developing countries. This is not a comprehensive review of adaptation actions – there are other resources that provide more in-depth reviews of adaptation. However, this circular aims to provide examples of the kinds of adaptation activities specifically addressing fisheries and/or aquaculture.
Miriam Kastner: Her findings on METHANE HYDRATES in Ocean Acidification Summ...www.thiiink.com
Atmospheric carbon dioxide (CO2) levels are rising as a result of human activities, such as fossil fuel burning, and are increasing the acidity of seawater. This process is known as ocean acidi cation. Historically, the ocean has absorbed approximately 30% of all CO2 released into the atmosphere
by humans since the start of the industrial revolution, resulting in a 26% increase in the acidity of the ocean1.
Ocean acidi cation causes ecosystems and marine biodiversity to change. It has the potential to affect food security and it limits the capacity of the ocean to absorb CO2 from human emissions. The economic impact of ocean acidi cation could be substantial.
Reducing CO2 emissions is the only way to minimise long-term, large-scale risks.
Ocean Acidification atau Pengasaman samudra adalah salah satu dampak peningkatan gas rumah kaca yang berupa CO2 dimana terjadi penurunan pH perairan akibat semakin banyaknya gas CO2 yang diserap laut/perairan
Ocean acidification is a term used to describe the changes in the chemistry of the Earth’s ocean i.e. ongoing decrease in the pH and increase in acidity caused by the uptake of anthropogenic carbon dioxide from the atmosphere causing major problems for the coral reefs and other organisms.
1. If present levels of greenhouse gas emissions are not reduced dramatically we will see further rises in:
Ocean temperatures
Over the last 50 years, mean global sea temperature has been increasing2
, alongside a dramatic increase in coral mortality and
reef degradation.3
The most recent 2007 IPCC assessment concluded that a 1.8-4.0°C increase in the average near-surface ocean
temperature is likely by the end of this century4
. Accelerating trends argue that the risk of exceeding these levels is increasing.
Bleaching events: In 1998 corals in over 60 nations experienced mass bleaching, ultimately resulting in the loss of 16% of the world’s reefs.6
In the last 10 years, the Great Barrier Reef has witnessed two major
bleaching events, damaging 50-60% in each event.2
With increases in sea surface temperature (SSTs) of 1-3°C, more frequent and severe coral bleaching episodes and widespread mortality are predicted.3,5
Most of
the Caribbean is expected to experience conditions that currently lead to coral bleaching every two years or more within the next 20 to 50 years, with temperatures increasing 1-2°C above the average warmest month
for periods of over a month.7,8,9
Increased disease: Elevated SSTs have been shown to accelerate the growth rate and disease activity of pathogens. Increased temperatures also reduce the host efficacy against disease10
.
Reduced coral biodiversity: Major changes in coral species diversity will occur with temperature-tolerant species being more viable than temperature sensitive species.11
Changes in aragonite saturation predicted as atmospheric CO2
concentration (ppm)
increases over shallow-water coral reef locations as pink dots. Before industrial revolution
(280 ppm) nearly all shallow-water coral reefs had aragonite saturation of > 3.25 (blue
regions in the figure).33
Sea levels
Coral reefs, especially those growing at their deepest limit, will be affected by rising water levels; reducing essential light.12
Major sea level rise scenarios
associated with loss of Greenland and WestAntarctic ice sheets may have great impacts on coral viability.As sea-levels rise and higher intensity tropical storms
batter already vulnerable coasts13
, increased terrestrial erosion will exacerbate coastal sedimentation. This will further damage the protective breakwater
normally offered by healthy reefs and result in a negative feedback loop.13
Frequency of extreme weather events
Extreme weather events including hurricanes and storm surges will increase in frequency and intensity. 2005 was the hottest recorded year in the Northern
Hemisphere. This coincided with a new maximum of recorded storms and hurricanes (26 and 13 respectively) and a major bleaching event. Across the
Caribbean islands, bleaching affected between 50% and 95% of coral communities. In the U.S. Virgin Islands 51.5% of corals declined due to these events
and subsequent outbreaks of disease.14
Ocean acidification
As rising CO2
dissolves, carbonic acid is formed, especially in surface waters and cold waters. The IPCC 2007 predicts that ocean pH will drop from 8.2 to
7.8 within this century, corresponding to around 150% increase in acidity4
In 2008, measurements of ocean pH taken from temperate coastal zones over a
period of 8 years, showed the decline in pH was between -0.039 and -0.05415, a rate significantly HIGHER than the 0.1 unit decrease since industrialisation
reported in 2005.16,20
Most corals are unlikely to survive in waters more acid than pH 7.6.35
Immediate and primary effects of acidification on corals are: reduced
ability to secrete calcium carbonate and reduced extension rates, dissolution and weakening of existing carbonate skeleton and so increased susceptibility
to weathering. Secondary changes that may result include: lowered reproductive success and reduced survival rates, and reduced variability in community
structure with potential selective advantage for non-calcifying reef organisms.17, 21
In 2007 it was widely believed that all reefs of the world would be under
significant acidification stress by 2050.2
Accelerating CO2
emissions are shortening this timeframe alarmingly.
Critical threshold levels
Determining critical non-viability thresholds to specific greenhouse gas concentrations will always be difficult, with understood
threshold levels becoming lower and more imminent as further research is carried out. We must stay well below these environmental
tipping points to limit the risk of ecosystem collapse and all the resultant impacts on human wellbeing.
Acidification thresholds: Reactions of coral species to increases in ocean pH decreases as predicted in the IPCC scenarios are
heterogeneous22,23,34
, however it appears that calcification rates of tropical-region reef building corals will see a 20-60% decline at
concentrations of CO2
around 560ppm.25, 26, 27
If CO2
levels were to reach three times pre-industrial levels, some species of reef-
building corals such as Galaxea fascicularis would see their calcification rates drop by more than 80%.28
Research29
has shown
that in some situations carbonate accretion approaches or reaches a negative net balance due to aragonite saturation values
when atmospheric CO2
reaches 480 ppm. Even in the absence of all other pressures, these decreases in calcification could prove
to be near fatal to whole communities. The magnitude of current pH change projected by 2100 is likely not to have occurred in
our oceans for more than 20 million years.30
Temperature thresholds: The average SST of the oceans is not as important to coral survival as regional maximum SST and
the frequency and degree of these extreme warming events. Increased average SSTs of less than 2°C above pre-industrial levels
across the year may not push all corals over temperature tolerance thresholds, however higher SSTs increase the likelihood of
extreme warming events which cause mass bleaching and mortality.2, 6
Above a 2°C rise in SSTs (often equated to CO2
equivalence
of >450ppm), substantial adaptation will be required for corals and their symbionts to tolerate the increasingly frequent and severe
warming events. 8, 9
Synergisms
The probability of negative synergisms between decreasing ocean pH levels, increased extreme weather events, increased
temperatures and sea level rise alongside already prevalent anthropogenic pressures on coral species must not be underestimated
and highlights the pressing need to reduce greenhouse gas emissions to a minimum threshold level. Therefore a precautionary
CO2
threshold of ≤400ppm should be considered an urgent priority, in light of current coral viability data. This critical threshold
may have to be lowered significantly further as new data is obtained and the integrity of wider natural systems is factored in.
“Reefs are the oceans canaries. We must heed their call. This call is not just for the reefs
themselves, but for all the great ecosystems of our oceans. These stand behind reefs like a row
of dominoes. If reefs fall, the rest will follow in quick succession. The Sixth Mass Extinction will
be upon us. It will be of our own making, and it will be unstoppable by any means whatsoever.”
(J.E.N Veron, 2008) www.coralreefresearch.org
Scenarios of reef structural changes with increasing temperature and CO2
concentrations.33
Wendy Foden (IUCN), Ove Hoegh-Guldberg (University of Queensland), Pricila Iranah (ZSL),
Aylin McNamara (ZSL), Paul Pearce-Kelly (ZSL), Alex Rogers (ZSL), Charles Sheppard (University
of Warwick), Mary Stafford Smith (Coral Reef Research) and J.E.N (Charlie) Veron (Coral Reef
Research). Contributing researchers: John Atkinson (ZSL), Joanna Corrie (ZSL), Rachel Downey
(ZSL), Holly Wallis-Copley (ZSL)
References
1. Roberts, E. 2003, Marine Scientist 2: 21-23. 2. Veron, J. E. N., 2008, London, Harvard University Press.
3. Pandolfi et al. 2003, Science 301: 955-958. 4. Parry, M., et al. Ed. 2007, WG II in Fourth Assessment Report of the IPCC. Cambridge. 5.
Marshall P.A. et al. 2006. Australia, Great Barrier Reef Marine Park Authority. 6. Glynn, P. W., 2006, Global Change Biology 2(6): 495-509.
7. Wilkinson, C. & Souter, D., 2008, Global Coral Reef Monitoring Network 8. Sheppard, C.R.C., 2003.Nature 425:294-297. 9. Sheppard,
C.R.C. & Rioja-Nieto R. 2005. Marine Environmental Research. 60: 389-396. 10. Porter, J.W. et al. 2001. Hydrobiologica. 460. 1-24 11.
Hoegh-Guldberg, O. 1999, Marine and Freshwater Research. 50. 839–866. 12. Smith & Buddemeier, 1992, Annual Review of Ecology and
Systematics 23: 89-118. 13. Sheppard, C.R.C. et al. 2005. Estuarine, Coastal and Shelf Science 64:223-234. 14. Donner, S. D. et al 2007,
PNAS 104(13): 5483-5488. 15. Wootton, J. T. et al. 2008, PNAS 105(48): 18848-18853. 16. Orr, J. C. et al., 2005, Nature 437 (7059): 681-686.
17. Kleypas, J. A., et al., 1999, Science 284(5411): 118. 18. Carpenter, et al. 2008. Science. 321. 560-563. 19. Donner, S.D, et al. 2005. Global
Change Biology. 11. 2251-2265 20. Sponberg, A. F., 2007, BioScience 57. 21. Kershaw, S., & Cundy, A., 2000, Routledge.288.
22. Anthony, K. R. N et al. 2008. PNAS 105: 17442-17446 23. Marubini, F., C. et al. 2003. Proc. Roy. Soc. Lond. B 270:179–184. 24. Guinotte
J.M. & Fabry V. ICES J. Mar. Sci. 2008; 65: 414-432. 25. Langdon, C. & M.J. Atkinson. 2005. J. Geophys. Res. 110: np. 26. Royal Society.
2005. Policy Document 12/05. 27. Kleypas, J.A. et al. 2006. St. Petersburg. 28. Marshall, A.T. & P.L. Clode. 2002. J. Exp. Biol. 205: 2107–
2113. 29. Hoegh-Guldberg, O. et al. 2007. Science 318: 1737–1742. 30. Feely, R.A. et al. 2004. Science 305: 362–366. 31. Baird, A., &
Maynard, J.A. 2008. Science .320. pp315. 32. Buddemeier et al. 2004, Pew Centre. 33. Hoegh-Guldberg et al, 2008, Science, 318: 1737-1742.
34. Sheppard, C., 2008, Marine Ecology Progress Series 362: 109-117. 35. Hall-Spencer et al. 2008. Nature 454: 96-99. 36. Foden et al, 2008,
IUCN Red List
Acknowledgments
Many thanks to Phil Holmes
Coral ecosystems hold more than 25% of all marine species1
and are of immense economic importance. Climate change
is advancing more rapidly than previously forecast, beyond any of the IPCC predictions.
Continuing atmospheric CO2
build-up will tip marine ecosystems into an altered environmental state, where corals reefs,
their inhabitants and many other marine organisms will no longer be viable. Deep emission cuts must be targeted now
to avoid the global loss of these priceless marine ecosystems.
The IUCN 2008 Red List Climate Change susceptibility assessment
Warm-water reef-building corals have been assessed by the IUCN to
see how many have intrinsic traits that make them vulnerable to climate
change. Traits include; temperature sensitivity by adults and larvae,
sedimentation, cyclones and dispersal ability. The assessment at this
stage does not factor in climate change scenarios which will likely show
even further increases of extinction risk in certain areas.
A total of 566 species out of 799 (71%), were found to have traits that
madethemsusceptibletoclimatechange.36
Theseresultsdonotinclude
the impacts of acidification on coral species. Many species (51%)
previously classified as non-threatened in the IUCN Red List were found
to be susceptible to climate change.18
Coral adaptation potential
Physiological acclimation and/or evolutionary mechanisms could delay the predicted impacts.18,31
Corals that form symbioses with
more than one symbiont can shift their populations so that they are dominated by their more thermally-tolerant symbiont. However,
these short-lived changes have not yet resulted in novel host-symbiont combinations that will survive the predicted changes in
temperature.2,18
Reduced coral and symbiont species biodiversity, as predicted by future temperature increases, will mean that
coral reef ecosystems are less resilient to other survival pressures.18
The change to high-tolerance symbionts, will mean that coral
will be less vigorous in growth as higher-tolerance species are less efficient.19
Long generation times and low genetic diversity
of coral suggest a slow adaptation rate.3
Repeated bleaching episodes have suggested that corals have exhausted their genetic
capacity to adapt to rising SSTs.5,7
Managing the unavoidable
For coral reefs to tolerate or adapt to the already unavoidable climate change impacts,
they need to be healthy and unstressed to maximise their resilience.32
Limiting pollution
and physical stresses, enhancing mangrove vegetation cover and maintaining balanced
fish communities are essential measures. The longer time frame of natural increases
in CO2
allows mixing and buffering of surface layers by deep ocean sinks as well as
adaptation to new environmental conditions by marine organisms. In contrast, when
atmospheric CO2
increases abruptly, its effects are intensified in shallow waters owing
to a lack of mixing, giving marine life little time to adapt.
Avoiding the unmanageable
If critical thresholds are exceeded there are no realistic response options capable of contending with the resultant altered states.
Levels of CO2
and other contributing GHG emissions mean that current ‘CO2
equivalence’ levels stand at an alarming 435ppm.
CO2
levels on its own being at 385ppm, much higher then pre-industrial levels of 278ppm. Whilst geo-engineering options offer
some temperature-mitigation potential, there is no realistic mitigation measure available to address the acidification threat under
present policy measures. Effective engagement with public and policy makers is the most urgent mitigation priority. How this
might be realised will depend on how effective we are at conveying the profound consequences (not least for human survival)
associated with such an altered state marine environment.
Dec 08 poster / v1
The 25,000km² of coral reef systems of the Chagos Archipelago provide an
opportunity for studying climate change impacts in the near absence of other
anthropogenic stressors. Although Chagos was affected by the 1998 mass
bleaching,colonynumbersandjuvenilerecruitmenthasbeenrecoveringinrecent
years34
. This offers some hope that if other human impacts are minimised we can
increasecoralreefscapacitytorecoverfromextremedieoff
events–providingcriticalimpact
thresholds are avoided.