Archive for the ‘Oceans’ Category
According to Worldwatch:
Sea level rise could be even higher than predicted this century.
“The average sea level around the world has risen a total of 222 millimeters (mm) since 1875, which means an annual rate of 1.7 mm (See Figure 1.) Yet at the end of this long period, from 1993 to 2009, the sea level rose 3.0 mm per year—a much faster rate.
An estimated 30 percent of the sea level increase since 1993 is a result of warmer ocean temperatures that cause the water to expand (thermal expansion).
Another 55 percent of the increase results from the melting of land-based ice, mainly from glaciers and the Greenland and Antarctic ice sheets. (Sea ice that melts does not contribute to sea level rise, as the volume remains constant.)
The other 15 percent of the rise is due to changes in terrestrial freshwater dynamics, such as wetland drainage and lowered water tables.”
Image credit: Flickr/climatesafety
I’ve just finished a major report on ocean acidification. I have published the executive summary below. You can click here to download the ocean acidification report as a pdf (approx 3.8Mb).
Executive Summary
Ocean acidification has been called “the other CO2 problem” and even “global warming’s evil twin”. It occurs when carbon dioxide dissolves in seawater, producing carbonic acid (H2CO3).
Carbonic acid rapidly dissociates to produce hydrogen (H+) and bicarbonate ions (HCO3-). The hydrogen ions so produced combine with carbonate ions(CO3), sourced from calcium carbonate (CaCO3) to form more bicarbonate. This reduces the amount of available calcium carbonate.
Ocean acidification must be recognized for what it is – A global challenge of unprecedented scale and importance that requires immediate action to halt the trend of increasing acidification (EPOCA 2009).
Calcium carbonate is used by many marine organisms (including coral, oysters, mussels and many types of plankton) to form shells and skeletons. Less calcium carbonate makes it harder for these organisms to precipitate calcium.
As the oceans have absorbed about one-third of all anthropogenic carbon dioxide, they are now 30% more acidic than in pre-industrial times. This drop in pH is already reducing calcification rates of some marine calcifiers, especially those in colder waters (which can absorb more CO2 than warmer seawater).
Many ocean species rely on calcium to make shells and skeletons.
If CO2 emissions continue on their current trajectory, oceans will be 3x – 5x more acidic than pre-industrial levels by 2100. This will be more acidic than at any time in t he last 300 million years. The effects of this are unprecedented, but likely to be overwhelmingly negative – major impacts that will probably ramify upwards through marine food chains to apex predators, and be accompanied by the widespread extinction of some ocean species (especially benthic plankton).
Ocean acidification could trigger a chain reaction of impacts through the marine food web, beginning with larval fish and shellfish, which are particularly vulnerable (EPOCA 2009)
Coral reefs will be placed under increasing threat as acidification progresses. If present emission rates continue it is thought that they will start to dissolve (ie calcium carbonate will be reabsorbed into solution) by 2050.
Because of major inertia in the system, the acidification process is essentially irreversible over any time frame meaningful to us (ie > 10,000 years). Likewise, even if we were to stop all CO2 emissions tomorrow, ocean pH would continue to drop for some time (at least decades) as it reached a new carbon equilibrium with the atmosphere.
Because acidification is independent of carbon dioxide’s effect as a greenhouse gas, geo-engineering strategies that aim to cool the planet without removing atmospheric CO2 will have no effect on ocean acidification. Approaches to offset acidification (such as the application of crushed limestone to the oceans) would need to be at such massive scales that they would be prohibitively expensive (both economically and environmentally).
The only real way to fix this problem is to stop emitting carbon dioxide.
Acidification will have impacts on key Australian marine ecosystems such as those of the Southern Ocean, marine protected areas on the southern margins of the Australian continent (the Great Australian Bight and Tasmanian seamounts) and, eventually the Great Barrier Reef (ACE-CRC 2008)
Now take action.
- We don’t have long to change things around.
- Ocean acidification is already making the calcified parts of some sea creatures thinner and lighter. It is happening right now, independent of global warming.
- Coral reefs are going to start disappearing by 2050 at the latest.
- Acidification has the same solution as global warming – rapid emissions reduction.
- Due to the long lag-times in the system, the quicker we reduce carbon dioxide emissions, the more effect it will have in the future.
Here’s what you can do – Tell someone about this problem. Do something today!!!Visit my ocean acidification resources page for videos and links to major learned reports on this topic. Watch this video:
VIDEOS AND MOVIES
Acid Test – The Global Challenge of Ocean Acidification (movie with Sigourney Weaver). Website.
A Sea Change Feature Film trailer and website.
UK Environment Secretary Hilary Benn (14.12.2009) Oceans Day at COP-15.
Dr. Jane Lubchenco, Administrator of the National Oceanic and Atmospheric Association, gives a demonstration during the Select Committee on Energy Independence and Global Warming Hearing, “The State of Climate Science” held on December 2, 2009. Parts 1 & 2.
Information on Bering Sea warming, coral bleaching and ocean acidification.
Ocean acidification – The big global warming story. Catalyst (Australian science show – 9:29 mins; 13.09.2007).
RADIO
Pacific warned of ocean acidification – ABC Radio Australia.
SCHOLARLY ARTICLES
Impacts of ocean acidification on marine fauna and ecosystem processes. Victoria J. Fabry, Brad A. Seibel, Richard A. Feely and James C. Orr. ICES Journal of Marine Science 2008; 65: 414–432.
PUBLICATIONS
Position Analysis – Australian ocean impacts of carbon dioxide emissions.
Briefing document on European impacts of ocean acidification
Ocean Acidification Summary for Policymakers 2009.
Ocean Acidification – The Facts (2009).
Future Oceans – Warming Up, Rising High, Turning Sour
Pew Center Brief on Ocean Acidification (2009)
Royal Society Report on Ocean Acidification
Impacts of Ocean Acidification on Coral Reefs and Other Marine Calcifiers
WEBSITES
OZCoasts – Australian website with good info and links.
Ocean Acidification – Official EPOCA site.
LINKS PAGES
Wikipedia Ocean Acidification Article (with EXTENSIVE scientific citations and external links)
The Science Behind ACID TEST: The Movie.
NOAA Ocean Acidification Site (links at bottom)
MEETINGS & SYMPOSIA
The Ocean In A High CO2 World (2004)
ORGANISATIONS
European Project on Ocean Acidification (EPOCA)
Marine Climate Change Impacts Partnership (MCCIP – UK)
NEWS
Whatever The Warming, Ocean Acidifies From Carbon-dioxide Buildup
ScienceDaily (2007-03-27) — A new study indicates that future changes in ocean acidification caused by atmospheric carbon dioxide emissions are largely independent of the amount of climate change caused by those emissions.
Ocean Acidification And Its Impact On Ecosystems
ScienceDaily (2008-05-29) — Emissions of carbon dioxide through human activities have a well known impact on the Earth’s climate. What is not so well known is that the absorption of this carbon dioxide by the oceans is causing inexorable acidification of sea water. But what impact is this phenomenon having on marine organisms and ecosystems?
Acidifying Oceans Add Urgency To Carbon Dioxide Cuts
ScienceDaily (2008-07-06) — It’s not just about climate change anymore. Besides loading the atmosphere with heat-trapping greenhouse gases, human emissions of carbon dioxide have also begun to alter the chemistry of the ocean. The ecological and economic consequences are difficult to predict but possibly calamitous, warn a team of chemical oceanographers, and halting the changes already underway will likely require even steeper cuts in carbon emissions than those currently proposed to curb climate change.
Global Scientists Draw Attention To Threat Of Ocean Acidification
ScienceDaily (2009-02-05) — More than 150 leading marine scientists from 26 countries are calling for immediate action by policy-makers to sharply reduce carbon dioxide emissions so as to avoid widespread and severe damage to marine ecosystems from ocean acidification.
Carbon Sinks Losing The Battle With Rising Emissions
ScienceDaily (2009-03-21) — The stabilizing influence that land and ocean carbon sinks have on rising carbon emissions is gradually weakening, scientists who attended the international Copenhagen Climate Change Conference.
Coral Reefs Exposed To Imminent Destruction From Climate Change
ScienceDaily (2009-07-16) — Leading ocean scientists and climate change experts agreed on a new level of atmospheric carbon dioxide that would need to be achieved to ensure the survival of coral reefs.
Ocean Acidification: Impact On Key Organisms Of Oceanic Fauna May Be Worse Than Predicted
ScienceDaily (2009-09-17) — In addition to global warming, carbon dioxide emissions cause another, less well-known but equally serious and worrying phenomenon: ocean acidification. Researchers have just demonstrated that key marine organisms, such as deep-water corals and pteropods (shelled pelagic mollusks) will be profoundly affected by this phenomenon during the years to come.
Increased Ocean Acidification In Alaska Waters, New Findings Show
ScienceDaily (2009-08-14) — The same things that make Alaska’s marine waters among the most productive in the world may also make them the most vulnerable to ocean acidification. According to new findings, Alaska’s oceans are becoming increasingly acidic, which could damage Alaska’s king crab and salmon fisheries.
Acidic oceans threaten marine life. Brisbane Times December 2009.
More on ocean acidification and climate change. I actually think that this issue will shortly overtake global warming as the focus of reducing greenhouse gas emissions.
Why do I say that?
Because it’s happening rapidly, has definite and measurable ecological and economic effects, and is harder for the climate change deniers to disprove (although I’m sure that they’ll try and think of something!).
Watch this space – Remember you heard it here first!!!
Polar bears increasingly endangered by the Arctic impacts of climate change
Arctic seas turn to acid putting vital food chain at risk
Carbon-dioxide emissions are turning the waters of the Arctic Ocean into acid at an unprecedented rate, scientists have discovered. Research carried out in the archipelago of Svalbard has shown in many regions around the north pole seawater is likely to reach corrosive levels within 10 years. The water will then start to dissolve the shells of mussels and other shellfish and cause major disruption to the food chain. By the end of the century, the entire Arctic Ocean will be corrosively acidic.
Oceans May Soon Be More Corrosive Than When The Dinosaurs Died
Increased carbon dioxide emissions are rapidly acidifying the world’s oceans and, if unabated, could cause a mass extinction of marine life similar to one that occurred when the dinosaurs disappeared. By comparing computer model predictions of changes in ocean chemistry with evidence from the fossil record, researchers have found a glimpse of the possible future for ocean life if society does not drastically curb carbon dioxide emissions.
Ocean Becoming More Acidic, Potentially Threatening Marine Life
A dramatic increase in carbon dioxide levels is making the world’s ocean more acidic, which may adversely affect the survival of marine life and organisms that depend on them, such as humans.
A modest new lab at the Rosenstiel School is the first of its kind to tackle the global problem of climate change impacts on corals. Fully operational this month, this new lab has begun to study how corals respond to the combined stress of greenhouse warming and ocean acidification. The lab is the first to maintain corals under precisely controlled temperature and carbon dioxide conditions while exposing them to natural light conditions.
Global ocean summer surface temperatures this year were the highest ever recorded, according to a US national climatic data centre announcement last week.
Ocean surface temperatures were the warmest for any August since record keeping began in 1880. For the June to August summer months, average ocean surface temperatures were 16.9 degrees Celsius, 0.6C above the 20th century average.
Combined average land and ocean surface temperatures were the second warmest on record for August, and the third warmest for the summer months.
Here in Australia, we had our warmest August (mid-winter for us) since climate records began.
The unusually warm summer ocean temperatures were due to climate change and El Niño. It is likely that more temperature records will be set during the coming two years if the El Nino event strengthens and persists.
So far 2009 has been the fifth warmest year on record. Some scientists suggest that the coming decade could well be the hottest in human history.
Sea temperatures are increasing due to global warming.
This may be news from 2006 but still important:
There will be virtually nothing left to fish from the seas by the middle of the century if current trends continue, according to a major scientific study.
Stocks have collapsed in nearly one-third of sea fisheries, and the rate of decline is accelerating.
Writing in the journal Science, an international team of researchers says fishery decline is closely tied to a broader loss of marine biodiversity.
“The way we use the oceans is that we hope and assume there will always be another species to exploit after we’ve completely gone through the last one,” said research leader Boris Worm, from Dalhousie University in Canada.
Depletion of fish stocks
“What we’re highlighting is there is a finite number of stocks; we have gone through one-third, and we are going to get through the rest,” he told the BBC News website.
Steve Palumbi, from Stanford University in California, one of the other scientists on the project, added: “Unless we fundamentally change the way we manage all the ocean species together, as working ecosystems, then this century is the last century of wild seafood.”
Ocean acidification has emerged as an extreme threat to marine ecosystems and fisheries – it may be the real threat from climate change, ready to blind-side us in just a few decades.
Why do I say that?
Our oceans have absorbed around one-third of the CO2 emitted so far. This (along with heat-absorption from the atmosphere) has had a moderating effect on temperature increases measured so far – climate change to date could have been worse than it is.
An unexpected problem has emerged, however.
When carbon dioxide dissolves in seawater it forms a weak acid (carbonic acid) – as CO2 has accumulated in oceans around the world, they have slowly but surely become more acidic (so far about one-tenth of one pH unit). Although the increase in acidity to date doesn’t seem like much, it is already having measurable biological and physical effects.
The main issue relates to the hardening (or calcification) of marine shells. Shell-forming organisms need a fairly narrow pH range to allow them to get calcium out of solution in seawater and deposit it in their shells.
But as the water becomes more acidic, shell calcification decreases, and at some point actually begins to reverse, causing shells and related structures (like coral reefs) to start dissolving – one study estimates that ALL coral reefs may cease to grow and start to dissolve when atmospheric CO2 reaches 560ppm. It is also likely that most regions will be inhospitable to coral reefs by 2050 (including Australia’s Great Barrier Reef).
This issue does not just affect oceans.
It affects all of us because it will cause major changes to marine food chains.
And if ocean ecosystems collapse, what happens to us?
Ocean acidification due to climate change
Further Reading
Acid In The Oceans: A Growing Threat To Sea Life
Can Corals Survive In A Warming World?
Report Warns about Carbon Dioxide Threats to Marine Life – download a PDF of “Impacts of Ocean Acidification on Coral Reefs and Other Marine Calcifiers.”
Ocean acidification: the other CO2 problem
According to an online report from The Sydney Morning Herald, climate change-related damage to Australia’s Great Barrier Reef will cost us some $37.5 billion during this century.
If greenhouse gas emissions are not reduced globally, the Great Barrier Reef is expected to be one of the first of Australia’s World Heritage sites seriously damaged. But chairman of the Great Barrier Reef Foundation Dr John Schubert warned that with climate change happening much faster than predicted, Australia must plan to ”adapt” the reef to save it from some level of damage scientists say is inevitable.
According to the article:
”There needs to be extra emphasis on the adaptation side,” said Dr Schubert, who is also the outgoing chairman of the Commonwealth Bank and sits on the board of BHP-Billiton and Qantas. He said the report by Oxford Economics was a conservative assessment of the losses if the reef was damaged by permanent bleaching.
Anemone Fish - Great Barrier Reef
Bleaching (due to higher water temperatures) is not the only threat facing coral reefs. With atmospheric CO2 levels rising fast, ocean acidification is fast becoming THE major threat to all marine ecosystems.
The oceans absorb a lot of the CO2 emitted by human activities. When it dissolves in seawater it forms carbonic acid – this makes the oceans more acidic.
Shell-forming sea creatures (including coral polyps) can only deposit calcium in their shells when pH is between a certain critical range (see diagram).And if they can’t harden their shells they can’t survive, or form coral reefs for that matter.
As the oceans become more acidic, it is likely that large areas will become less hospitable to marine life – this will damage ocean food webs significantly as many crustaceans (and related species) are food for fish and other animals higher up the food chain.
More about ocen acidification coming soon…
Posted in Ocean Acidification, Uncategorized | Tags: coral, great-barrier-reef, Ocean Acidification | No Comments »
The world’s ocean surface temperature was the warmest on record for June, breaking the previous high mark set in 2005, according to a preliminary analysis by NOAA. Additionally, the combined average global land and ocean surface temperature for June was second-warmest on record. The global records began in 1880.
Global Climate Statistics
- The combined global land and ocean surface temperature for June 2009 was the second warmest on record, behind 2005, 1.12 degrees F (0.62 degree C) above the 20th century average of 59.9 degrees F (15.5 degrees C).
- Each hemisphere broke its June record for warmest ocean surface temperature. In the Northern Hemisphere, the warm anomaly of 1.17 degrees F (0.65 degree C) surpassed the previous record of 1.12 degrees F (0.62 degree C), set in 2005. The Southern Hemisphere’s increase of 0.99 degree F (0.55 degree C) exceeded the old record of 0.92 degree F (0.51 degree C), set in 1998.
- The global land surface temperature for June 2009 was 1.26 degrees F (0.70 degree C) above the 20th century average of 55.9 degrees F (13.3 degrees C), and ranked as the sixth-warmest June on record.
The global ocean surface temperature for June 2009 was the warmest on record, 1.06 degrees F (0.59 degree C) above the 20th century average of 61.5 degrees F (16.4 degrees C).
Ocean surface temperature warmest on record for June
Notable Developments and Events
- El Niño is back after six straight months of increased sea-surface temperature anomalies. June sea surface temperatures in the region were more than 0.9 degree F (0.5 degree C) above average.
- Terrestrial warmth was most notable in Africa. Considerable warmth also occurred in Siberia and in the lands around the Black and Mediterranean Seas. Cooler-than-average land locations included the U.S. Northern Plains, the Canadian Prairie Provinces, and central Asia.
- Arctic sea ice covered an average of 4.4 million square miles (11.5 million square kilometers) during June, according to the National Snow and Ice Data Center. This is 5.6 percent below the 1979-2000 average extent. By contrast, the 2007 record for the least Arctic sea ice extent was 5.5 percent below average. Antarctic sea ice extent in June was 3.9 percent above the 1979-2000 average.
- Heavy rain fell over central Europe, triggering mudslides and floods. Thirteen fatalities were reported. According to reports, this was central Europe’s worst natural disaster since the 2002 floods that claimed 17 lives and caused nearly $3 billion in damages.
Posted in Oceans | Tags: climate change evidence, global warming effects, ocean temperatures | No Comments »
