September 24th, 2010 by Jim Just
Professor Orrin Pilkey, one of America’s most outspoken coastal geologists, warns we’re set to experience one of the first major impacts of global warming: sea levels will rise by 2 meters by 2100.
Two meters far exceeds the projections of the International Panel on Climate Change (IPCC) in its 4th Assessment Report, which range from a low of .18 meters to a high of .59 meters. However, the IPCC report contains this disclaimer:
This report does not assess the likelihood, nor provide a best estimate or an upper bound for sea level rise.
The IPCC projections explicitly exclude future rapid dynamical changes in ice flow from the Greenland and Antarctic ice sheets. The IPCC range assumes a near-zero net contribution of the Greenland and Antarctic ice sheets to future sea level rise, on the theory that Antarctica’s ice sheets will gain mass from an increase in snowfall.
The two-meter rise that Pilkey warns is possible is consistent with recent research based on semi-empirical models.

Estimates for twenty-first century sea level rise from semi-empirical models as compared to the IPCC Fourth Assessment Report
Semi-empirical models have the merit that they reproduce past sea level rise very well, unlike the physical models used thus far. But they too have a serious limitation: there is no way to ensure that the historic relationship between sea level rise and temperature will continue to hold in future. The semi-empirical approach does not account for non-linear changes. When it comes to ice sheets, the relationship between temperature and sea level rise may not be linear, and the ranges shown in the chart above could underestimate future sea level rise.
Pilkey says more needs to be done to prepare coastal communities from climate change threats – including planning for an orderly retreat.
If you’re going to have development and its close to the beach, make sure the buildings movable. It means you recognise there’s rising sea levels and you move things back as required, or you demolish the buildings.
As sea levels rise over the next 50 to 100 years, we can try to fortify and protect existing development, and repair it when damaged. But in many cases, retreat will eventually be the only option. Whole communities may have to be relocated. Where will the money come from, and who will pick up the tab? These questions are certain to be at the center of future political and legal battles.
Johnny Cash said his song Five Feet High and Rising wasn’t just a lamentation about destruction. The flood waters left a blessing in their wake.
My mama always taught me that good things come
from adversity if we put our faith in the Lord.
We couldn’t see much good in the flood waters
when they were causing us to have to leave home,
but when the water went down, we found
that it had washed a load of rich black bottom dirt across our land.
The following year we had the best cotton crop we’d ever had.
But this time, the water’s not coming down – at least not anytime soon. Or maybe we just need to take a longer view of things.
Orrin Pilkey is Professor Emeritus of Earth Sciences, and Founder and Director Emeritus of the Program for the Study of Developed Shorelines (PSDS) within the Nicholas School of the Environment at Duke University.
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September 23rd, 2010 by Jim Just
Arctic summer sea ice cover is in a death spiral. It’s not going to recover.
This foreboding statement is from Mark Serreze, director of the National Snow and Ice Data Center.
More than 2.5 million additional square kilometers of Arctic Ocean waters have been opened up to the heat of the 24-hour summer sun, absorbing tremendous amounts of extra heat. A warmer Arctic Ocean not only takes much longer to re-freeze, it emits huge volumes of additional heat energy into the atmosphere, disrupting the weather patterns of the northern hemisphere.
Especially worrisome to Serreze is warming in the coastal regions of the Arctic, where average temperatures are now three to five degrees C warmer than they were 30 years ago:
I hate to say it but I think we are committed to a four- to six-degree warmer Arctic.
If the Arctic warms by six degrees, half of the world’s permafrost is likely to thaw, releasing carbon and methane accumulated over thousands of years. And methane is much more potent as a greenhouse gas than carbon dioxide.
Serreze said Arctic sea ice has reached its four lowest summer extents in the last four years – and ice volume likely reached the lowest ever level this month. On September 15, NSIDC called the end of the 2010 ice melt season, with sea ice extent at its third lowest ever. On September 21, NSIDC withdrew its call. What looked to be an unusually early end to the melt season is turning out to be an unusually late end.

This summer’s Arctic ice melt was notable for another reason besides near-record low ice extent and probable record low ice volume: the Norwegian-crewed Northern Passage, a 31-foot fiberglass sailing boat equipped only with a 10 horsepower outboard motor for emergencies, circumnavigated the Arctic Ocean, traversing both the Northwest and Northern Passages.

Tags: Arctic ice
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September 18th, 2010 by Jim Just
On September 15 the National Snow and Ice Data Center reported Arctic ice extent had started increasing again, calling September 10 the end of the 2010 Arctic melt season and pegging 2010 as the third-lowest ever recorded, behind 2007 and 2008.
But not so fast! Their daily image update shows sea ice extent declining again. Sea ice extent has now fallen below that recorded on September 10.

The late-season dip shows up even better in this chart at the Japan Aerospace Exploration Agency website.

The IJIS website explains why their data may differ slightly from NSIDC’s:
In general, sea-ice extent is defined as a temporal average of several days (e.g., five days) in order to eliminate calculation errors due to a lack of data (e.g., for traditional microwave sensors such as SMMR and SSM/I). However, we adopt the average of two days to achieve rapid data release. The wider spatial coverage of AMSR-E enables reducing the data-production period.
Sea ice extent is defined as the areal sum of sea ice covering the ocean (sea ice + open ocean).
NSIDC reported sea ice extent on September 10, 2010 at 4.76 million km². According to IJIS, the minimum as of September 17 was 4.83 million km² – 120,000 km² below the September 10 extent of 4.95 million km² and just 130,000 km² above the minimum extent of 470,7813 km² reached on September 9, 2008.
Note that IJIS data on sea ice extent differs slightly from NSIDC data. The IJIS web site explains that they average the most recent two days of data rather than the more widespread methodology of averaging five days of data to “achieve rapid data release.” But this wouldn’t seem to explain why their numbers are higher than NSIDC’s.
Ice extent has been falling more than 50,000 km² a day for the past four days. If that decline keeps up for just a couple more days, the 2010 minimum extent would dip below the 2008 mark and become the second lowest ever recorded.
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September 16th, 2010 by Jim Just
The National Snow and Ice Data Center (NSIDC) reports Arctic sea ice appears to have reached its annual minimum extent on September 10. This melt season confirms that the trend of decreasing summer sea ice is continuing.
The minimum ice extent was the third lowest in the satellite record, after 2007 and 2008.

This is only the third time in the satellite record that ice extent has fallen below 5 million square kilometers (1.93 million square miles) – and all those occurrences have been within the past four years.
Assuming that we have indeed reached the seasonal minimum extent, 2010 came respectably near record lows despite seeing the shortest melt season in the satellite record. The melt season got a late start and appears to have ended early, spanning only 163 days between the seasonal maximum and minimum ice extents.
Joseph Romm at Climate Progress reports that scientists confirm the oldest, thickest ice is disappearing.
NSIDC scientist Julienne Stroeve explains what this chart means:
This figure would support thinning of the icepack over the last couple of decades since older ice tends to be thicker than younger ice. You can see in this figure how little of the really old, and thick ice there is left in the Arctic Basin.
The Polar Science Center, using the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS), calculates that the monthly average Arctic Sea Ice Volume for May 2010 was the lowest May volume over the 1979–2010 period, 42% below the 1979 maximum and 32% below the 1979–2009 May average. So far, September 2009 holds the record for lowest ice volume, at 67% below its 1979 maximum. We’ll soon see if that record will be broken in 2010.
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September 1st, 2010 by Jim Just
A study published in the September issue of the Journal of the Geological Society found that increasing CO2 levels are causing foram diversity to plummet:
A unique ‘natural laboratory’ in the Mediterranean Sea is revealing the effects of rising carbon dioxide levels on life in the oceans. The results show a bleak future for marine life as ocean acidity rises, and suggest that similar lowering of ocean pH levels may have been responsible for massive extinctions in the past.
Rising carbon dioxide levels acidify the ocean, which has a particularly devastating effect on organisms that have calcium carbonate shells, like Foraminifera. The study, published in the September issue of the Journal of the Geological Society, found that increasing CO2 levels caused foram diversity to fall from 24 species to only 4. The study found a tipping point occurs at mean pH 7.8, the pH level predicted for the end of this century.
Forams record past events in the geological record. The Paleocene-Eocene Thermal Maximum (PETM), 55 million years ago, was a period of massive carbon release and rapid warming, accompanied by extinctions in marine life.
This statement by study co-author Dr. Jason Hall-Spencer in the Geological Society’s press release is not optimistic:
Our natural laboratory provides a glimpse into the future of our oceans.
Joseph Romm at Climate Progress has posted this chart showing trends in ocean CO2 concentrations and pH at one sampling station off Hawaii.

Romm also points out that the disappearance of forams has grave implications for the rest of the food chain.
For an analysis of what that could mean, see 2009 Nature Geoscience study concludes ocean dead zones “devoid of fish and seafood” are poised to expand and “remain for thousands of years.”
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September 1st, 2010 by Jim Just
Dr. Jeff Masters at WunderBlog reports that both the Northwest Passage and the Northern Sea Route are now open. Data at the University of Illinois site Cryosphere Today shows it is now possible to completely circumnavigate the Arctic Ocean in ice-free waters – and this will probably continue to be the case for at least a month.
Arctic sea ice extent image for August 24, 2010, as compiled by The University of Illinois Cryosphere Today. The northern route (Western Parry Channel) through the Northwest Passage was completely clear of ice, as was the Northeast Passage. The southern route through the Northwest Passage was still partially blocked.
This year marks the third consecutive year–and the third time in recorded history–that both the Northwest Passage and Northern Sea Route have melted free, according to the National Snow and Ice Data Center.
The Northeast Passage opened for the first time in recorded history in 2005, and the Northwest Passage in 2007. It now appears that the opening of one or both of these northern passages is the new norm.
Here’s an updated graphic:

As this graphic from Chris Mooney’s article in New Scientist shows, ice volume has been decreasing even more precipitously than ice area.

The average volume of Arctic ice between July and September has fallen from 21,000 cubic kilometres in 1979 to 8000 cubic kilometres in 2009, a 55% decline compared with the 1979 to 2000 average. This is even faster than the decline in ice extent, which is 40% below the long-term average.
Not only has the total volume of Arctic ice continued to decline since 2007 considerably more quickly than predicted by most climate models, the rate of loss is accelerating. The Arctic Ocean may soon be essentially ice-free during the summer months. The dark ocean waters, mostly devoid of ice, would then absorb still more sunlight, further warming the overlying atmosphere during an increasingly lengthy ice-free season, reshaping weather throughout the region and well beyond it.
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August 26th, 2010 by Jim Just
A good friend recently asked me why I give so much attention to news about Arctic sea ice extent at this blog, saying he just glosses over posts on this subject.
Here’s the reason: the area of sea ice cover is an important, amplifying climate feedback. Loss of sea ice is a cause of concern because as the area of ice decreases, increased absorption of sunlight by the darker ocean causes more sea ice melting. As this graph from Makiko Sato & James Hansen’s new blog shows, Arctic sea ice extent has been declining steadily . . .

. . . as has sea ice volume. What ice remains is getting thinner.

It’s not just sea ice that is melting. Ice sheets are shrinking too, both in Greenland and in Antarctica.

And the ice loss over the last few years has been at a time of minimum solar irradiance. Solar irradiance is now once again on the upswing.

It seems likely that September Arctic sea ice may be all but gone within a few decades – or perhaps even sooner. What does less Arctic sea ice mean for Earth’s weather patterns?

NASA is predicting loss of summer sea ice will mean more severe winter storms in the northern hemisphere – a prediction which is already being borne out.
Following Arctic sea ice extent is fascinating because it shows that global warming is not something to worry about in the future. Global warming is here and now, and is already affecting us in our daily lives. What’s worrisome is that the impacts will only get more severe. By the time the impacts are bad enough to get our attention, it will be too late – the damage will already have been done. Under the best-case scenario it will take Earth a thousand years or more to recover. Under the worst-case scenario, Earth will flip into a different, stable climate regime which won’t be hospitable to human existence.
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August 25th, 2010 by Jim Just
According to the National Snow and Ice Data Center (NSIDC), neither the Northwest Passage through the Canadian Arctic nor the Northern Sea Route along the coast of Siberia are yet free of ice and open – but it’s looking like they soon will be.
A Russian gas tanker set out from Murmansk on August 14 across the Northern Sea Route, escorted by two nuclear ice breakers, and is expected to deliver its cargo of gas condensate to China by early September.
Northern Sea Route (blue) and alternative route through Suez Canal (red)

Ice in the Vilkitsky Strait is the only remaining impediment to shipping across the Northern Sea Route . . .

. . . as seen in this NSIDC graphic of sea ice extent.

While this latest graphic shows the northern route of the Northwest Passage as being open, NSIDC’s Arctic Sea Ice News reports that as of August 17 neither the northern route (Western Parry Channel) nor the southern route (Amundsen’s Passage) through the Northwest Passage were completely clear of ice. NSIDC says that sea ice area within the northern route is currently well below the 1968 to 2000 average and almost a month ahead of the clearing that was observed in 2007. In the southern route, there is still a substantial amount of ice.
Ice concentration on August 16, 2010. Lines mark two well-known routes through the Northwest Passage: Amundsen’s route is yellow, and the northern route is red.

If winds push sea ice away from the entrance to M’Clure Strait, the northern route of the Northwest Passage could open again this year – if it hasn’t already.

M'Clure Strait, Northwest Territories, Canada.
On August 21, 2007, the Northwest Passage became open to ships without the need of an icebreaker. The Northwest Passage opened again on August 25, 2008. In late August 2008, satellite images showed that the last ice blockage of the Northern Sea Route had melted – which would be the first time since satellite records began that both the Northwest Passage and Northern Sea Route were open simultaneously.
The Northern Sea Route was open in 2005 but closed again by 2007. A Russian nuclear icebreaker escorted a small convoy including two Western commercial vessels westward through the Northern Sea Route in 2009.
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August 2nd, 2010 by Jim Just
Microscopic life crucial to the marine food chain is dying out. The consequences could be catastrophic.
So reads the headline of an article in the U.K. Independent reporting on new research published in the journal Nature. The study, titled Global phytoplankton decline over the past century, finds there has been a 40% decline in the ocean’s phytoplankton over the last 100 years – and global warming is to blame.
The microscopic plants that support all life in the oceans are dying off at a rate of about 1% per year. The decline is related to rising sea surface temperatures.
According to the Independent, the scientists said if the findings are confirmed by further studies, the decline in phytoplankton will represent the single biggest change to the global biosphere in modern times, even bigger than the destruction of the tropical rainforests and coral reefs. Phytoplankton are microscopic marine organisms capable of photosynthesis, just like terrestrial plants. They float in the upper layers of the oceans, provide much of the oxygen we breathe and account for about half of the total organic matter on Earth. Phytoplankton are the basis of life in the oceans and are essential in maintaining the health of the oceans. A 40% decline would represent a massive change to the global biosphere.
The press release explains that in warmer oceans, the water becomes stratified, with warmer water on top of colder deeper water. Nutrients which are normally replenished by upwelling colder water are cut off, and the photosynthesizers living in the surface waters starve to death.
Rising sea surface temperatures were negatively correlated with phytoplankton growth over most of the globe, especially close to the equator. Phytoplankton need both sunlight and nutrients to grow; warm oceans are strongly stratified, which limits the amount of nutrients that are delivered from deeper waters to the surface ocean. Rising temperatures may contribute to making the tropical oceans even more stratified, leading to increasing nutrient limitation and phytoplankton declines.
Dave Cohen points out we’re caught in a nasty downward spiral:
It is clear that we have a disastrous positive feedback loop at work here, in which warmer surface water supports fewer phytoplankton, which then take up less CO2 from the atmosphere, which causes the surface water to warm some more due to the greenhouse effect, etc.
Here’s the abstract of the Nature article:
In the oceans, ubiquitous microscopic phototrophs (phytoplankton) account for approximately half the production of organic matter on Earth. Analyses of satellite-derived phytoplankton concentration (available since 1979) have suggested decadal-scale fluctuations linked to climate forcing, but the length of this record is insufficient to resolve longer-term trends. Here we combine available ocean transparency measurements and in situ chlorophyll observations to estimate the time dependence of phytoplankton biomass at local, regional and global scales since 1899. We observe declines in eight out of ten ocean regions, and estimate a global rate of decline of ~1% of the global median per year. Our analyses further reveal interannual to decadal phytoplankton fluctuations superimposed on long-term trends. These fluctuations are strongly correlated with basin-scale climate indices, whereas long-term declining trends are related to increasing sea surface temperatures. We conclude that global phytoplankton concentration has declined over the past century; this decline will need to be considered in future studies of marine ecosystems, geochemical cycling, ocean circulation and fisheries.
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July 20th, 2010 by Jim Just
The National Snow and Ice Data Center (NSIDC) reports the rate of ice loss in the Arctic slowed in the first half of July, primarily because of a change in atmospheric circulation as the dipole anomaly, an atmospheric pattern that dominated the Arctic in June, broke down.

The report explains:
Through much of May and June, high pressure dominated the Beaufort Sea with low pressure over Siberia. Winds associated with this pattern, known as the dipole anomaly, helped speed up ice loss by pushing ice away from the coast and promoting melt.
However, the dipole anomaly pattern broke down in early July. In the first half of July, cyclones (low pressure systems) generated over northern Eurasia tracked eastward along the Siberian coast and then into the central Arctic Ocean, where they tend to stall. This cyclone pattern is quite common in summer. The low-pressure cells have brought cooler and cloudier conditions over the Arctic Ocean. They have also promoted a cyclonic (anticlockwise) sea ice motion, which acts to spread the existing ice over a larger area. All of these factors likely contributed to the slower rate of ice loss over the past few weeks.
In the last few days, high pressure has started to build again in the Beaufort Sea, but whether this will continue remains to be seen.
Still, Arctic sea ice extent at this time is the second lowest ever recorded, as seen in this chart from the Japan Aerospace Exploration Agency website, IJIS.

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July 7th, 2010 by Jim Just
The National Snow and Ice Data Center (NSIDC) reports Arctic sea ice declined at the fastest rate ever recorded in June, and the average ice extent in June was the lowest in the satellite data record (from 1979 to 2010).

The previous record for the fastest rate of June decline was set in 1999. The linear rate of monthly decline for June over the 1979 to 2010 period is now 3.5% per decade.

Whether or not 2010 will see a new record low set for Arctic sea ice extent depends upon weather patterns. NSIDC explains:
The record low ice extent of September 2007 was influenced by a persistent atmospheric pressure pattern called the summer Arctic dipole anomaly (DA). The DA features unusually high pressure centered over the northern Beaufort Sea and unusually low pressure centered over the Kara Sea, along the Eurasian coast. In accord with Buys Ballot’s Law, this pattern causes winds to blow from the south along the Siberian coast, helping to push ice away from the coast and favoring strong melt. The DA pattern also promotes northerly winds in the Fram Strait region, helping to flush ice out of the Arctic Ocean into the North Atlantic. The DA pattern may also favor the import of warm ocean waters from the North Pacific that hastens ice melt.
June 2010 saw the return of the DA, but with the pressure centers shifted slightly compared to summer 2007. As a result, winds along the Siberian coastal sector are blowing more from the east rather than from the south. Whether or not the DA pattern persists through the rest of summer will bear strongly on whether a new record low in ice extent is set in September 2010.
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July 5th, 2010 by Jim Just
A report in Science magazine brings together dozens of studies that collectively paint the dismal picture that the deterioration of ocean health is rapidly approaching the point where it may be irreversible.
Ove Hoegh-Guldberg, director of the Global Change Institute at the University of Queensland in Australia and a co-author of the report, says:
This is further evidence we are well on our way to the next great extinction event.
Important conclusions in the report, titled The Impact of Climate Change on the World’s Marine Ecosystems, include:
- The average temperature of the upper level of the oceans has increased more than 1 degree Fahrenheit during the past 100 years, and global ocean surface temperatures in January were the second warmest ever recorded for that month.
- Though the increase in acidity is slight, it represents a “major departure” from the geochemical conditions that have existed in the oceans for hundreds of thousands if not millions of years.
- Nutrient-poor “ocean deserts” in the Pacific and Atlantic oceans grew by 15 percent from 1998 to 2006.
- Oxygen concentrations are dropping off the Northwest U.S. coast and the coast of southern Africa, where dead zones appear regularly. There is paleontological evidence that declining oxygen levels in the oceans played a major role in at least four or five mass extinctions.
- Since the early 1980s, the production of phytoplankton, a crucial part of the food chain, has declined 6 percent, with 70 percent of the decline found in the northern parts of the oceans. Scientists also found that phytoplankton are becoming smaller.
Here’s the abstract:
Marine ecosystems are centrally important to the biology of the planet, yet a comprehensive understanding of how anthropogenic climate change is affecting them has been poorly developed. Recent studies indicate that rapidly rising greenhouse gas concentrations are driving ocean systems toward conditions not seen for millions of years, with an associated risk of fundamental and irreversible ecological transformation. The impacts of anthropogenic climate change so far include decreased ocean productivity, altered food web dynamics, reduced abundance of habitat-forming species, shifting species distributions, and a greater incidence of disease. Although there is considerable uncertainty about the spatial and temporal details, climate change is clearly and fundamentally altering ocean ecosystems. Further change will continue to create enormous challenges and costs for societies worldwide, particularly those in developing countries.
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May 24th, 2010 by Jim Just
A new paper in the journal Nature titled Robust warming of the global upper ocean concludes that the world’s oceans have been warming more than previously thought – and more than even climate models were suggesting.
RealClimate has posted this graph showing the measured warming as compared to previous and model estimates:

Basically, if the total flux of energy entering the Earth’s atmosphere is greater than energy losses, then has to go somewhere – and that somewhere is mainly the ocean. Other reservoirs for this excess energy, like the land surface or melting ice, are much smaller and are for most purposes negligible.
An article about the study by Jason Socrates Bardi quotes Kevin Trenberth of the National Center for Atmospheric Research in Boulder, Colorado (Trenberth was not involved with the study):
Ninety percent of the energy [trapped by increased greenhouse gases] goes into the ocean. It’s important to track this in order to properly understand what is happening in the climate system. If you dump heat in the ocean and it gets moved around and reappears somewhere, it has consequences in terms of the weather patterns.
Another new study in the journal Oceanography titled The Volume of Earth’s Ocean finds the Earth’s ocean is smaller than the most recent published estimates, by a volume equivalent to 500 times the Great Lakes or five times the Gulf of Mexico. The study’s authors used satellite altimetry data to better measure ocean depth and thus to more accurately estimate the ocean’s volume.

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May 19th, 2010 by Jim Just
This transcript of a talk by Jeremy Jackson talking about how we wrecked the ocean, posted at The Oil Drum, may be the saddest thing I’ve ever read.
Jackson describes himself as “an ecologist, mostly a coral reef ecologist.” He talks about the degradation of coral reefs and ocean ecosystems that he’s seen in his lifetime. Scientists used to believe that coral reefs and oceans were infinitely resilient – after all, they’ve survived for untold millennia. But they have succumbed to but a few decades of abuse by humans.
And we got it all wrong. And the reason was because of overfishing, and the fact that a last common-grazer, a sea urchin, died. And within a few months after that sea urchin dying, the seaweed started to grow. And that is the same reef. That’s the same reef 15 years ago. That’s the same reef today. The coral reefs of the north coast of Jamaica have a few percent live coral cover and a lot of seaweed and slime. And that’s more or less the story of the coral reefs of the Caribbean, and increasingly, tragically, the coral reefs worldwide.
Now, that’s my little, depressing story. All of us in our 60s and 70s have comparable depressing stories. There are tens of thousands of those stories out there. And it’s really hard to conjure up much of a sense of well-being, because it just keeps getting worse. And the reason it keeps getting worse is that, after a natural catastrophe, like a hurricane, it used to be that there was some kind of successional sequence of recovery, but what’s going on now is that overfishing and pollution and climate change are all interacting in a way that prevents that. And so I’m going to sort of go through and talk about those three kinds of things.
Jackson does go on to talk about those things. About fish disappearing. About habitat destruction, the sea floor being turned into a desert of mud. About biological pollution and seas becoming poisonous. About warming oceans and dying corals. And about the synergies among these tragedies, the positive feedback loops, that are making the whole of the catastrophe vastly greater than the sum of the parts.
Jackson’s prognosis?
So what are the oceans going to be like in 20 or 50 years? Well, there won’t be any fish except for minnows, and the water will be pretty dirty, and all those kinds of things, and full of mercury, etc., etc. And dead-zones will get bigger and bigger, and they’ll start to merge. And we can imagine something like the dead-zonification of the global, coastal ocean. Then you sure won’t want to eat fish that were raised in it, because would be a kind of gastronomic Russian roulette. Sometimes you have a toxic bloom; sometimes you don’t. That doesn’t sell.
The really scary things though are the physical, chemical, oceanographic things that are happening. As the surface of the ocean gets warmer, the water is lighter when it’s warmer, it becomes harder and harder to turn the ocean over. We say, it becomes more strongly stratified. The consequence of that is that all those nutrients that fuel the great anchoveta fisheries, or the sardines of California, or in Peru, or whatever, those slow down, and those fisheries collapse. And, at the same time, water from the surface, which is rich in oxygen, doesn’t make it down, and the ocean turns into a desert.
The shame of being human is sometimes unbearable.
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February 21st, 2010 by Jim Just
A recent post reported on scientists’ findings that Greenland’s glaciers are melting from the bottom up. Findings from another team of scientists help explain why: subtropical waters from warmer latitudes are reaching Greenland’s glaciers, driving melting and likely triggering an acceleration of ice loss.

Credit: Jack Cook, Woods Hole Oceanographic Institution
The research team, led by Fiamma Straneo, a physical oceanographer at Woods Hole Oceanographic Institution, found that subtropical waters are reaching Greenland’s glaciers, driving melting and likely triggering an acceleration of ice loss. Melting ice also means more fresh water in the ocean, which could flood into the North Atlantic and disrupt a global system of currents, known as the Ocean Conveyor.
Science Daily quotes Straneo:
This is the first time we’ve seen waters this warm in any of the fjords in Greenland. The subtropical waters are flowing through the fjord very quickly, so they can transport heat and drive melting at the end of the glacier.
The Greenland ice sheet’s contribution to sea level rise over the last decade has doubled due to increased melting and especially to the widespread acceleration of outlet glaciers.
The research teamconducted two extensive surveys during July and September of 2008 in Sermilik Fjord, a 100-kilometer long glacial fjord in East Greenland connecting Helheim Glacier with the Irminger Sea. In 2003 alone, Helheim Glacier retreated several kilometers and almost doubled its flow speed. Deep inside the fjord, researchers found subtropical water as warm as 39 degrees Fahrenheit (4 degrees Celsius). The team also reconstructed seasonal temperatures on the shelf using data collected by 19 hooded seals tagged with satellite-linked temperature depth-recorders. The data revealed that the shelf waters warm from July to December, and that subtropical waters are present on the shelf year round.
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February 17th, 2010 by Jim Just
The National Marine Fisheries Service (NMFS ) is considering listing corals as endangered species under the Endangered Species Act. From the Federal Register:
[W]e initiate status reviews of 82 species of corals to determine if listing under the ESA is warranted.
In October 2009 NMFS received a petition from the Center for Biological Diversity to list 83 species of coral as threatened or endangered under the ESA. The petition asserts that synergistic threats of ocean warming, ocean acidification, and other impacts affect these species and that these global habitat threats are exacerbated by local habitat threats posed by ship traffic, dredging, coastal development, pollution, and agricultural and land use practices that increase sedimentation and nutrient loading. The petition states that immediate action is needed to reduce greenhouse gas concentrations to levels that do not jeopardize these species and requests that critical habitat be designated for these corals concurrent with listing under the ESA.
A species or subspecies is ‘‘endangered’’ if it is in danger of extinction throughout all or a significant portion of its range, and ‘‘threatened’’ if it is likely to become endangered within the foreseeable future throughout all or a significant portion of its range.
NMFS will have to “assess conservation measures to determine whether they ameliorate a species’ extinction risk” and, once critical habitat is designated, ensure that Federal agencies do not fund, authorize or carry out any actions that are likely to destroy or adversely modify that habitat.
Any area may be excluded from a critical habitat designation if the benefits of exclusion outweigh the benefits of designation, unless excluding that area “will result” in extinction of the species. So economic and national security considerations could trump the science.
So much for the “immediate action” that is needed to reduce greenhouse gas concentrations.
It’s nothing but Kabuki theater – highly stylized ritual rather than meaningful action or even honest discussion. action.
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January 28th, 2010 by Jim Just
New NASA-led research shows that the melt season for Arctic sea ice has lengthened by an average of 20 days over the span of 28 years, or 6.4 days per decade.
The research team discovered that the melt season lengthened the most – more than 10 days per decade – in Hudson Bay, the East Greenland Sea, the Laptev and East Siberian Seas, and the Chukchi and Beaufort Seas.
Earlier melt means more heat can be absorbed by the open water, promoting more melting and later freeze-up dates — more than eight days per decade later in some areas.
Thorsten Markus of NASA’s Goddard Space Flight Center in Greenbelt, Md. explains how the feedback loop works:
This feedback process has always been present, yet with more extensive open water this feedback becomes even stronger and further boosts ice loss. Melt is starting earlier, but the trend towards a later freeze-up is even stronger because of this feedback effect.
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January 25th, 2010 by Jim Just
Scientists have upped their estimates of the waves that a “100 year event” might produce along the coast of the Pacific Northwest. Their finding heighten concerns for flooding, coastal erosion and structural damage.

Waves crawl up against the lower level of a structure in Neskowin, Oregon, during a storm in January, 2008. (Photo by Armand Thibault, Neskowin)
As recently as 1996, the maximum in ocean wave heights was estimated to be 33 feet. In a study just published online in the journal Coastal Engineering, scientists from Oregon State University and the Oregon Department of Geology and Mineral Industries conclude that the highest waves may be as much as 46 feet and the 100-year wave height could actually exceed 55 feet. Impacts of the bigger waves would dwarf impacts expected from sea level rise in coming decades.
Over the last few decades, increasing wave heights have had 2 – 3 times the impact of sea level rise in terms of erosion, flooding and damage. The largest wave height increases have occurred off the Washington and northern Oregon coasts, with less increase in southern Oregon and nothing of significance south of central California.
Possible causes cited are changes in storm tracks, higher winds, more intense winter storms, or other factors probably related to global warming but also possibly related to periodic climate fluctuations such as the Pacific Decadal Oscillation. What is clear is that waves are getting bigger.
The significant rise in sea level expected over future decades and centuries will only add to the damage already being done by higher waves.
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January 22nd, 2010 by Jim Just
Scientists have found evidence confirming predictions of climate models that higher atmospheric CO2 levels will lead to acidification of Earth’s oceans.
Scientists from the University of South Florida College of Marine Science measured CO2 levels in the northeastern Pacific Ocean. By comparing pH readings from 1991 and from 2006, they found the first direct evidence of acidification across an entire ocean basin, leaving no doubt that growing CO2 levels in the atmosphere are exerting major impacts on the world’s oceans.
If greenhouse gas emissions continue unabated, by the end of the century surface water pH would drop approximately 0.4 pH units and the carbonate ion concentration would decrease almost 50%. This surface ocean pH would be lower than it has been for more than 20 million years. Even if substantial reductions in emissions are made, ocean acidification will continue for hundreds of years to come, which means we are already committed to many centuries of ugly consequences.
The study is published in the American Geophysical Union’s journal Geophysical Research Letters.
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January 7th, 2010 by Jim Just
The rapid loss of summer ice cover over the Arctic Ocean is creating internal waves in the Arctic waters that could dramatically accelerate the sea ice loss.
That’s what Luc Rainville of the University of Washington’s Applied Physics Laboratory in Seattle and his colleague Rebecca Woodgate report in a study just published in the latest issue of Geophysical Research Letters.
Underwater waves in the Pacific and Atlantic, stirred up by surface winds, keep the oceans from becoming stratified in layers. Near Hawaii, for example, such underwater waves have been measured at depths of up to 200 meters, preventing the ocean from becoming a quiet pool with warm waters on top and colder waters below. The ice-topped Arctic Ocean, on the other hand, is just such a stratified, calm place because sea ice muffles all waves “like a big damper,” as Rainville explains. But that is becoming less the case as summer sea ice melt is opening up ever wider expanses of water.
Unlike any other ocean basin, the Arctic has a lot of very fresh, very cold water on top from melted ice – the cold halocline layer. But below about 100 meters the waters become very salty and slightly warmer. If internal waves become powerful enough to mix these waters, then the warmer surface could accelerate the melting of sea ice.
Here’s the abstract:
The Arctic is generally considered a low energy ocean. Using mooring data from the northern Chukchi Sea, we confirm that this is mainly because of sea ice impeding input of wind energy into the ocean. When sea ice is present, even strong storms do not induce significant oceanic response. However, during ice free seasons, local storms drive strong inertial currents (>20 cm/s) that propagate throughout the water column and significantly deepen the surface mixed layer. The large vertical shear associated with summer inertial motions suggests a dominant role for localized and seasonal vertical mixing in Arctic Ocean dynamics. Our results imply that recent extensive summer sea ice retreat will lead to significantly increased internal wave generation especially over the shelves and also possibly over deep waters. This internal wave activity will likely dramatically increase upper layer mixing in large areas of the previously quiescent Arctic, with important ramifications for ecosystems and ocean dynamics.
The National Snow and Ice Data Center reports temperatures over the Arctic this winter have so far been unusually warm. Paradoxically, this could affect the winds that push the ice out of the Arctic to warmer waters, helping to retain some of the second- and third-year ice through the winter and potentially rebuild some of the older, multiyear ice that has been lost over the past few years. However, NSIDC cautions it is not known whether these weather conditions will persist through the winter or what the net effect will be.
As the chart below shows, Arctic sea ice extent has been declining steadily over the past 30 years.

Arctic sea ice is now tracking at or near record lows.

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