Climate Denial Crock of the Week – “The Medieval Warming Crock”

Another great Peter Sinclair video about a denier favorite: the Medieval Warm Period.

You can read about this crock here at SkepticalScience:

The skeptic argument: The Medieval Warm Period was warmer than current conditions. This means recent warming is not unusual and hence must be natural, not man-made.

What the science says: While the Medieval Warm Period saw unusually warm temperatures in some regions, globally the planet was cooler than current conditions.

The Medieval Warm Period spanned 950 to 1250 AD and corresponded with warmer temperatures in certain regions. During this time, ice-free seas allowed the Vikings to colonize Greenland. North America experienced prolonged droughts.

The Medieval Warm Period was not a global phenomenon. Warmer conditions were concentrated in certain regions. Some regions were even colder than during the Little Ice Age. To claim the Medieval Warm Period was warmer than today is to narrowly focus on a few regions that showed unusual warmth. However, when we look at the broader picture, we see that the Medieval Warm Period was a regional phenomenon with other regions showing strong cooling. Globally, temperatures during the Medieval Period were less than today.

Also see articles on the RealClimate site on the MWP here and here.

[youtube=http://www.youtube.com/watch?v=vrKfz8NjEzU&w=560&h=340]

Climate Shifts Round-up for 2009

As 2010 begins, we figured it was an apt time to do a round-up of 2009 here it at Climate Shifts. It has been an exciting year – we enlisted several new bloggers, created 327 posts and greatly expanded our readership. With thirteen scientists and experts in the field of coral reefs and climate change writing commentaries, the blog is expanding to a considerable expertise.

Since we moved to more reliable servers (carbon-netural green hosting!) at the end of September we’ve had 10,539 unique visitors with over 35,572 page views (excluding bots). We’ve had people from 152 countries/territories from from 2,628 cities reading our posts:

In other news, the Global Change Institute at the University of Queensland officially commenced on January 1st 2010 under the guidance of Ove, and John is heading down under to Brisbane with his family for a sabbatical at UQ. Onwards to 2010! We are planning some changes for next year and would really appreciate hearing from you what type of content you want us to provide.

See below for a few stats from our plugins (again since September) – seems that the notorious Andrew Bolt post drew a few deniers out of the woodwork with 2578 views and 48 comments.

most rated posts

  1. COP15: Cold and grey but buzzing with excitement and hope. 472 votes, average: 5.00 out of 5472 votes, average: 5.00 out of 5472 votes, average: 5.00 out of 5472 votes, average: 5.00 out of 5472 votes, average: 5.00 out of 5 (5.00 out of 5)
  2. “Macro-algal dominated coral reefs: shake that ASS” 4 votes, average: 5.00 out of 54 votes, average: 5.00 out of 54 votes, average: 5.00 out of 54 votes, average: 5.00 out of 54 votes, average: 5.00 out of 5 (5.00 out of 5)
  3. More climate delusionism and questionable science 3 votes, average: 5.00 out of 53 votes, average: 5.00 out of 53 votes, average: 5.00 out of 53 votes, average: 5.00 out of 53 votes, average: 5.00 out of 5 (5.00 out of 5)
  4. Humpty dumpty and the ghosts 3 votes, average: 5.00 out of 53 votes, average: 5.00 out of 53 votes, average: 5.00 out of 53 votes, average: 5.00 out of 53 votes, average: 5.00 out of 5 (5.00 out of 5)
  5. Testing the ‘macroalgal dominated coral reefs’ paradigm 2 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 5 (5.00 out of 5)
  6. Local stressors act to reduce the resilience of corals to bleaching events 2 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 5 (5.00 out of 5)
  7. Maldives President Calls Underwater Meeting 2 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 5 (5.00 out of 5)
  8. Hot Pink Beasties of the Deep 2 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 5 (5.00 out of 5)
  9. Preservation of coral reefs: why isn’t the majority heard? 2 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 5 (5.00 out of 5)
  10. Corals likely to starve in a high CO2 world 2 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 52 votes, average: 5.00 out of 5(5.00 out of 5)

most viewed posts

  1. Happy Birthday to… Andrew Bolt! – 2,578 views
  2. “Macro-algal dominated coral reefs: shake that ASS” – 1,593 views
  3. The never-ending jellyfish joyride – 1,511 views
  4. “Great Barrier Reef could adapt to climate change, scientists say” – Facts, fallacies and fanciful thinking. – 1,126 views
  5. Why the existence of ‘heat tolerant’ corals does not mean that coral reefs will be able to resist climate change. – 1,096 views
  6. PLoS One: an open access venue for coral reef science – 955 views
  7. ExxonMobil still funding climate change sceptics – 893 views
  8. The coral reef crisis: The critical importance of <350 ppm CO2 – 843 views
  9. Catch of the day: invasive lionfish – 814 views
  10. Doom and Boom on a Resilient Reef: Climate Change, Algal Overgrowth and Coral Recovery – 784 views

There is so much great science being done in the oceans, on coral reefs and on climate change and so many important policy debates, it can be overwhelming trying to keep up and cover it all.  Luckily there are a number of awesome online resources, at least regarding climate change.  Below is a list of our favorites, in no particular order:

  • RealClimate: An amazing resource from real climate scientists.  The comments can be very educational too.
  • Skeptical Science: The webs best debunker of denier myths.
  • All the Peter Sinclair videos (which can be seen here and on YouTube)
  • ClimateProgress (a very thorough coverage of climate change policy and science, even though Joe verges on hysteria at times)
  • Malaria, Bedbugs, Sea Lice and Sunsets:  Always interesting and informative commentary from a boots on the ground coral reef conservation scientist.
  • Deltoid: Tim Lambert tells it how it is
  • David Horton: David blogs about the environment and social justice here and on the Huff Post here
  • Monbiot.com: A collection of George Monbiot’s provocative essays

The aftermath of Copenhagen – where are we headed?

These two graphics from the Climate Interactive website are probably the clearest and most easy to understand images i’ve seen yet detailing the fallout from COP15. The ‘potential’ proposals (highlighted in green) are alot more promising than the official confirmed proposals. Some of these seem incredibly ambitious, such as Costa Rica proposing 0% emissions by 2021 (although Costa Rica is 99% clean energy already).

In the grand scheme of things, what does this mean? The Sustainability Institute have simulated the effects of CO2 emissions under the COP15 scenarios and determined the impacts upon atmospheric CO2 concentrations and temperature increase over pre-industrial levels.

The results aren’t pretty – under the current confirmed proposals, in 2100 we would see CO2 levels peak at 780ppm – far above the recommended 350ppm for the worlds coral reefs. Even the low emissions pathway would see the world at 470ppm by the end of the century, and the ‘business as usual scenario’ is incredibly concerning.

Along these lines, we’ve added a global ‘scorecard’ to the front page that calculates the increases in global temperature using the information above. The scorecard and analysis is updated continuously – when the proposals change, the position of the blue line on the thermometer changes:

http://widgets.clearspring.com/o/4b0afdf054484c54/4b400c878bc70b45/4b0bd9e53e5935f6/b72b179d

Steve Netwriter: skeptic or denier?

The river Nile

What should those who refuse to acknowledge evidence that the earth is warming be called?  Skeptics?  Deniers?

Mike Kaulbars has thoroughly tackled this question here with an excellent collection of his essays on the difference between skeptics and deniers on his Greenfrye blog.  (also look at his “about” page here – Mike I feel your frustration!)

But back to Steve Netwriter:

John,

No name calling, no quotes from authorities, no disrespect, etc. Just a respectful exchange of evidence. Like they do it in a courtroom.

That’s pretty rich coming from an author who uses “denier” in just about every post.

I suggest you stop first, then you might get some respect.

Can you please tell me what exactly the “deniers” are supposed to be denying.
I’ll help you out with a definition of “denial”:

Quote:
Denial is a defense mechanism in which a person is faced with a fact that is too painful to accept and rejects it instead, insisting that it is not true despite what may be overwhelming evidence.
http://en.wikipedia.org/wiki/Denial_%28disambiguation%29

Here is a small sample of what Mike Kaulbars has to say about the difference between skeptics and deniers (I recommend reading his full post here):

I am reminded with some frequency that the term “Denier” is offensive. I am aware of that. Why does no one raise the question of whether the term is accurate? Shouldn’t that be the real question?

Here are the terms that I think might describe the range of doubt we encounter:

  • Naive
  • Doubters
  • Agnostics
  • Contrarians
  • Skeptics
  • Deniers

Skeptics are those who acknowledge the scientific evidence, but thoughtfully maintain doubt based on some small evidence or logic that, though meagre, is nonetheless reality based. They are honourable people who push science forward through their constant, reasoned questioning and thoughtful critiques of the dominant paradigm.

Skepticism is a disciplined intellectual activity based on facts. Just what it means in the modern sense is explored intelligently at places like the Skeptics Society and here. No doubt there are many more, but those give you a sense.

By contrast those who distort and lie (see “Debunking Nonsense” at right, and every post on this blog), who demonstrate no understanding of the science, who have no evidence or rational logic for their position but persist in denying the very existence of the overwhelming scientific evidence, can only be called Deniers.

Mark Hoofnagle describes “What is Denialism” on his Denialism blog quite thoroughly; I cannot recommend his blog highly enough for the analysis of denalism.

So, far from being synonyms the terms describe two radically different groups. This point is made repeatedly  throughout the discussions of the issue. For eg here, and here, and here, and here, and here (you get the idea).

Johnny Rook even goes so far as to break down the Deniers into:

1) Plutocrats
2) Shills
3) Literate conservative/libertarian ideologues
4) The right-wing booboisie

“Denier” is an ugly and crude word to describe an ugly and crude behaviour.

Some argue that the term Denier should not be used as it puts the other person on the defensive. True enough, and good reason to never use the term carelessly or inaccurately.

But it should always be used when describing denial.

Also see this post by Mike and this one here;

rational folks have stopped pretending that the climate change Deniers are actually “skeptics”, anything but!

Skepticism, after all, is a rational, intellectual process that  involves critical analysis of the facts and reasoned doubt applied to all evidence and hypotheses.

“The key to skepticism is to continuously and vigorously apply the methods of science to navigate the treacherous straits between “know nothing” skepticism and “anything goes” credulity.” skeptic.com

In contrast, Climate change Deniers:

  • ignore the facts and evidence;
  • do not critically examine any evidence or hypotheses;
  • unquestionably embrace any counter proposal, no matter how transparently absurd or false.

Also see these definitions by naught101:

skeptic – Noun – http://en.wiktionary.org/wiki/skeptic

  1. Someone undecided as to what is true.
  2. Someone who habitually doubts accepted beliefs and claims presented by others, requiring strong evidence before accepting any belief or claim.

denier – Noun – http://en.wiktionary.org/wiki/denial

  1. Someone who denies something.

Steve Netwriter asked a while back for some info about AGW:

So I ask for a list of facts supported by overwhelming evidence that are being “denied”. Just saying “AGW” will not do. I require a detailed list of facts with supporting evidence.

Now I have a very simple question.

Where is the AGW?

All I see is a natural fluctuation.
To me the IPCC charts, which only go back about 1000 years, appear to mislead because they do not put the recent temperature fluctuations into context.
Surely one must put things into context. That is after all what Phil Jones, and Michael Mann et al keep repeating in reply to accusations about their emails.

So, I have simply put the IPCC charts into context.
And I repeat

Where is the AGW?

If you claim it is there, how can it be distinguished from the natural variations?

This again is at the heart of this debate, so I am sure you can answer that easily.

Thank you.

Where is the evidence for warming?  There are so many places to go.  Start here:

OK, now that we have established that the earth is indeed warming, why do scientists think most of the observed recent warming is being cause by human activities (e.g, greenhouse gas emissions, deforestation, industrial agriculture, etc)?   Because the hypothesis is supported by theory, our knowledge of climate dynamics, past relationships between forcing factors (solar cycles, CO2 conc., etc.) and climate (via paleo-climate records), and the very strong (undeniable) observed relationship between modern CO2 concentration (i.e., increases caused by humans) and temperature.

Does this large body of theory and evidence lead to 100% certainty?  Certainly not.  But it would be very hard to make a rationale, skeptical argument that there isn’t a strong likelihood that humans are in large part responsible for the recent (last ~ 100 years) warming on earth.

If one piece in this chain of evidence and logic were broken, I’d become skeptical myself.  I hope that happens.  Then I can get back to doing the basic science I love and to enjoying my vacation at the beach.

Why do deniers think the earth is cooling?

Given how obvious the evidence for continued global warming is, how can so many people insist the earth is cooling?  Even some scientists are making this argument (which just proves you don’t need to be all that smart to be a scientist).

For example, in a recent comment on Climate Shifts, Ron Henzel said:

The track record of global warming kool aid pushers isn’t exactly a sterling one. The decade which is now closing was supposed to be the hottest on record, and we all know how that went. Geologist Dr. David Gee, chair of the science committee of the 2008 International Geological Congress and author of 130 plus peer reviewed papers said, “For how many years must the planet cool before we begin to understand that the planet is not warming? For how many years must cooling go on?” (Dr. Gee is currently at Uppsala University in Sweden.)

Ron questions the precautionary principle and the application of it to climate change on his blog (see our post on this here).  Further he suggests that his readers go here for “real information on issues pertaining to climate change”

  1. Climate Depot (a kind of “Drudge Report” for climate issues).
  2. Climate Audit (Steve McIntyre is the man who demonstrated that Al Gore’s infamous “hockey stick” graph was a statistical absurdity.)
  3. Watts Up With That? (one of the best global warming skeptic blogs, edited by former TV meteorologist Anthony Watts).
  4. “U. S. Senate Minority Report: More Than 700 International Scientists Dissent Over Man-Made Global Warming Claims Scientists Continue to Debunk ‘Consensus’ in 2008 & 2009″
  5. Cornwall Alliance (a conservative evangelical response to global warming alarmism).

If you are remotely familiar with the AGW debate, you know how fully debunked the wacky claims made on these sites are.

Also see this article by Christopher Booker in the “Hawaii Reporter”, excerpted below:

2008: Another Grim Year for the Global Warmers
By Michael R. Fox Ph.D., 1/2/2009 10:45:23 AM

The year 2008 marked the tenth consecutive year of no global warming. This is not widely reported or known. In fact the Earth has been cooling for the last 6 years.

“Earth has cooled since 1998 in defiance of the predictions by the U.N.-IPCC. … The global temperature for 2007 was the coldest in a decade and the coldest of the millennium … which is why ‘global warming’ is now called ‘climate change.'” – Climatologist Dr. Richard Keen of the Department of Atmospheric and Oceanic Sciences at the University of Colorado.

The irrepressible Christopher Booker has noted the large changes in the global warming events during 2008 (http://tinyurl.com/8p7d83).

These include:

  • 1. Global temperatures continue to decline. Booker says “The decline in global temperatures was wholly unpredicted by all those computer models which have been used as the main drivers of the scare. Last winter, as temperatures plummeted, many parts of the world had snowfalls on a scale not seen for decades. This winter, with the whole of Canada and half the US under snow, looks likely to be even worse. After several years flatlining, global temperatures have dropped sharply enough to cancel out much of their net rise in the 20th century.”

So, why do deniers think the earth is cooling when it clearly isn’t?

(1) They base their opinions on proclamations of others, rather than examining factual evidence and making up their own minds.

(2) They fundamentally misunderstand what is being predicted about the earth’s temperature.  Nobody has ever predicted that it will warm every year, with each new year being warmer than the last.  Given all the factors that determine climate and global temperature, that would be an idiotic prediction.  The prediction is that there will be a warming trend of climate, i.e., on average, over long periods of time (decades to centuries) the earth will warm on average (not everywhere to the same degree).

(3) They simply confuse weather and climate (as has been pointed out here and countless other places over and over again).

Whatever the reason, they are lying about the climate record and deceiving the public with statements like these “Earth has cooled since 1998 in defiance of the predictions” “The track record of global warming kool aid pushers isn’t exactly a sterling one. The decade which is now closing was supposed to be the hottest on record, and we all know how that went.”

Compare these lies with the evidence, such as this figure from the WMOs recent report which stated “The decade of the 2000s (2000–2009) was warmer than the decade spanning the 1990s (1990–1999), which in turn was warmer than the 1980s (1980–1989)”:

See some of our many posts on this here, here, here and here.

Solar cycles and global warming: why the next decade is likely to be the warmest yet

There is a good article at Climate Progress about the role of solar cycles in climate warming. The intensity of the sun has been relatively low, which mutes the effects of greenhouse gases on global warming.  There was speculation earlier last year that we could be heading toward an even lower phase, but more recent evidence and models suggest otherwise.  As Joe Romm says on this new post: “2009 ends with a “sunspot surge” as solar cycle 24 revs up”.

From ClimateProgress: The 2000s were  the hottest decade in recorded history by far — even though we’re at “the deepest solar minimum in nearly a century.”  The 2000s were a full 0.2°C warmer than the 1990s, which of course had been the hottest decade on record, 0.14°C warmer than 1980s (according to the dataset that best tracks planetary warming).  Hmm.  It’s almost like the warming is accelerating.

NASA reported in September were becoming less frequent:

The sun is in the pits of the deepest solar minimum in nearly a century. Weeks and sometimes whole months go by without even a single tiny sunspot. The quiet has dragged out for more than two years, prompting some observers to wonder, are sunspots disappearing

If sunspots do go away, it wouldn’t be the first time. In the 17th century, the sun plunged into a 70-year period of spotlessness known as the Maunder Minimum that still baffles scientists. The sunspot drought began in 1645 and lasted until 1715; during that time, some of the best astronomers in history (e.g., Cassini) monitored the sun and failed to count more than a few dozen sunspots per year, compared to the usual thousands.

“Whether [the current downturn] is an omen of long-term sunspot decline, analogous to the Maunder Minimum, remains to be seen,” Livingston and Penn caution in a recent issue of EOS. “Other indications of solar activity suggest that sunspots must return in earnest within the next year.”

From Climate Progress: When we last looked at the sun [please, don’t try that at home], NASA was reporting that the sunspot cycle was about to come out of its depression, if a newly discovered mechanism for predicting solar cycles — a migrating jet stream deep inside the sun — proved accurate (see National Solar Observatory, NASA say no “Maunder Minimum”). It now appears TSI is well on its way to recovering, as NASA and others had predicted

Even as Solar Cycle 24 picks up, it won’t affect global temperatures quickly.  Again, as  NASA explained in January:

Because of the large thermal inertia of the ocean, the surface temperature response to the 10-12 year solar cycle lags the irradiance variation by 1-2 years. Thus, relative to the mean, i.e, the hypothetical case in which the sun had a constant average irradiance, actual solar irradiance will continue to provide a negative anomaly for the next 2-3 years.

To Save the Planet, Save the Seas

There was a great guest op-ed in the NYT on December 27, 2009 about the importance of plant life in the oceans as carbon sinks or sponges for all the carbon (CO2) people are producing on the land.

See our related posts on this here, here and here.

And read lots more about this concept and the role of algae, seagrass, and phytoplankton as carbon stores at the Blue Carbon website here.

To Save the Planet, Save the Seas

By DAN LAFFOLEY

Peterborough, England

FOR the many disappointments of the recent climate talks in Copenhagen, there was at least one clear positive outcome, and that was the progress made on a program called Reducing Emissions From Deforestation and Forest Degradation. Under this program, key elements of which were agreed on at Copenhagen, developing countries would be compensated for preserving forests, peat soils, swamps and fields that are efficient absorbers of carbon dioxide, the primary heat-trapping gas linked to global warming.

This approach, which takes advantage of the power of nature itself, is an economical way to store large amounts of carbon. But the program is limited in that it includes only those carbon sinks found on land. We now need to look for similar opportunities to curb climate change in the oceans.

Few people may realize it, but in addition to producing most of the oxygen we breathe, the ocean absorbs some 25 percent of current annual carbon dioxide emissions. Half the world’s carbon stocks are held in plankton, mangroves, salt marshes and other marine life. So it is at least as important to preserve this ocean life as it is to preserve forests, to secure its role in helping us adapt to and mitigate climate change.

Sea-grass meadows, for example, which flourish in shallow coastal waters, account for 15 percent of the ocean’s total carbon storage, and underwater forests of kelp store huge amounts of carbon, just as forests do on land. The most efficient natural carbon sink of all is not on land, but in the ocean, in the form of Posidonia oceanica, a species of sea grass that forms vast underwater meadows that wave in the currents just as fields of grass on land sway in the wind.

Worldwide, coastal habitats like these are being lost because of human activity. Extensive areas have been altered by land reclamation and fish farming, while coastal pollution and overfishing have further damaged habitats and reduced the variety of species. It is now clear that such degradation has not only affected the livelihoods and well-being of more than two billion people dependent on coastal ecosystems for food, it has also reduced the capacity of these ecosystems to store carbon.

The case for better management of oceans and coasts is twofold. These healthy plant habitats help meet the needs of people adapting to climate change, and they also reduce greenhouse gases by storing carbon dioxide. Countries should be encouraged to establish marine protected areas — that is, set aside parts of the coast and sea where nature is allowed to thrive without undue human interference — and do what they can to restore habitats like salt marshes, kelp forests and sea-grass meadows.

Managing these habitats is far less expensive than trying to shore up coastlines after the damage has been done. Maintaining healthy stands of mangroves in Asia through careful management, for example, has proved to cost only one-seventh of what it would cost to erect manmade coastal defenses against storms, waves and tidal surges.

The discussions in Copenhagen have opened the way for all countries to improve the management of oceans and coasts to harness their immense potential to mitigate climate change — especially over the next decade, while the world’s politicians, scientists and engineers develop longer-term strategies for stabilizing the atmospheric concentration of greenhouse gases.

In their continuing negotiations on climate change, nations should now make it a priority to produce a single map of the world that documents all the different types of coastal carbon sinks, and identify the ones that are in most immediate need of preservation. New studies should be undertaken to better understand how best to manage these areas to increase carbon sequestration. Then, following the example of the forests program, it will be possible to establish formulas for compensating countries that preserve essential carbon sinks in the oceans.

We urgently need to bring the ocean into the agenda alongside forests so that, as soon as possible, we can help the oceans to help us.

Dan Laffoley is the marine vice chairman of the World Commission on Protected Areas at the International Union for Conservation of Nature and the principal specialist for marine at Natural England.

Model to data temperature comparisons – how well did they do?

In the last few months, we’ve heard the comment “Notwithstanding the dramatic increases in man-made CO2 emissions over the last decade, the world’s warming has stopped” pushed around with alarming regularity. We discussed this in a previous posting (‘Abbott’s climate change policy is “bullshit”‘) which included a great analysis by Tamino, who demonstrated pretty well that the temperature this decade did exactly as expected – it’s getting warmer (see also “WMO finds 2000–2009 the warmest decade; so much for that “global warming pause” meme“)

Another one of those re-occurring memes that’s been posted here on the comments section of Climate Shifts is that the “computer climate models (are) known to not be able to predict future climate very well” and “observational evidence does not match the models to date“. Considering that it’s almost the end of the first decade of the 21st century, it seems like a good time to be checking our predictions and future projections of climate change. Enter Gavin from Real Climate, who points out the vital importance of “updat(ing) all of the graphs of annual means with another single datapoint”:

Above is the annual mean anomalies from the IPCC AR4 models (black line) and their 95% envelope (grey shading) and the surface temperature records from HadCRUT3v (red line) and GISTEMP (blue lines). As Gavin points out:

As you can see, now that we have come out of the recent La Niña-induced slump, temperatures are back in the middle of the model estimates. If the current El Niño event continues into the spring, we can expect 2010 to be warmer still.

So far, the model predictions are looking solid. We can pretty much debunk the meme “observational evidence does not match the models to date“.

Next up, Gavin deals with a pretty key question: how does the oldest of all climate models hold up? Below are three scenarios from Hansen’s 1988 paper on climate projections:

How about that “computer climate models (are) known to not be able to predict future climate very well” meme? It seems like even the first GCM model did a pretty good job of predicting the increases in temperature pretty well, although the B & C scenarios are a little warm compared to the actual surface temperature records.  To conclude:

…despite the fact these are relatively crude metrics against which to judge the models, and there is a substantial degree of unforced variability, the matches to observations are still pretty good, and we are getting to the point where a better winnowing of models dependent on their skill may soon be possible. (Read more over @ Real Climate)

Ocean acidification turns up the volume

What was that? Can’t hear me? Don’t worry, ocean acidification will fix that.

According to a new paper published in Nature Geoscience, as the oceans become more acidic through increased atmospheric CO2, the changes in seawater chemistry will result in fewer reactions and less acoustic used. This means that sound will travel further, and therefore be louder at a fixed distance than under less acidic conditions.

Sound absorption attenuation as a function of frequency and seawater pH (Ilyina et al 2010)

The authors predict that by 2100, sound absorption could fall by up to 60% high latitudes regions of the world. Most of the absorption of sound occurs at low frequencies (1,000 to 5,000 hertz) – the same range as propellor noises, ship sounds and military sonar. Marine noise is a huge issue in the oceans, and is already known to harm cetaceans (‘i’m beached as, bro‘) – and this is projected to get louder and louder:

Temporal evolution of seawater pH and sound absorption coefficient in acoustic hotspots (Ilyina et al 2010)

“We’re not saying that during the next 100 years all dolphins will be deafened,” Dr. Zeebe said. “But the background noise could essentially override or mask the sounds that they’re depending on.” (Read More)

Ilyina et al (2010) Future ocean increasingly transparent to low-frequency sound owing to carbon dioxide emissions Nature Geoscience (3)18-22

ENSO Wrap-Up

The Australian Bureau of Meteorology has posted an updated report on the status of the current ENSO.  You can read the full report here.  Hightlights include:

Pacific Ocean temperatures remain at levels typical of a mature El Niño. Over the past fortnight, Trade winds have remained weak over the central tropical Pacific, resulting in further warming of the underlying ocean. As a result, central Pacific Ocean surface temperatures are now at their warmest level since the El Niño of 1997-98, exceeding temperatures observed in both the 2002-03 and 2006-07 events. During the past week, small regions which are more than 3°C above their average temperature have emerged along the equator.

Leading climate models continue to suggest tropical ocean temperatures are approaching their peak, and will remain above El Niño thresholds through the southern summer before starting to cool.

Over the past fortnight, the Southern Oscillation Index has fallen slightly, and remains at levels typical of an El Niño event. Similarly, cloudiness and rainfall near the equator remains enhanced, while eastern Austrailan rainfall remains low; all typical of a mature El Niño event. However, the influence of El Niño events on Australian rainfall typically declines by mid to late summer.

  • The tropical Pacific Ocean sea surface remains significantly warmer than the long-term average in central and eastern areas.
  • The sub-surface water of the tropical Pacific remains warmer than the long-term average.
  • The latest approximate 30-day SOI value is −10; the monthly value for November was −7. The SOI has remained relatively stable throughout December.
  • Trade winds are weaker than normal across the Pacific.
  • Cloudiness near the date-line has increased over the past fortnight.
  • All of the above are consistent with a moderately strong El Niño, which most leading international computer models surveyed by the Bureau predict will persist through the southern hemisphere summer, but decline thereafter.