Algal Blooms: Not Caused by Global Warming

It seems that global warming is as easy to blame as “the devil made me do it” these days. Almost anything can be blamed on global warming it seems. It has become the new universal evil, replacing the threat of communism as the new global menace. But it doesn’t always deserve the blame for things that happen in our world, and with a little digging, you can often find that blaming global warming for a variety of ills and changes is about as credible as blaming the boogeyman. Consider algae blooms for example.

Earlier this year we saw this story

Harmful Algae Takes Advantage Of Global Warming: More Algae Blooms Expected

ScienceDaily (Apr. 7, 2008 ) — You know that green scum creeping across the surface of your local public water reservoir? Or maybe it’s choking out a favorite fishing spot or livestock watering hole. It’s probably cyanobacteria — blue-green algae — and, according to a paper in the April 4 issue of the journal Science, it relishes the weather extremes that accompany global warming. more…

Now we have this new factual story:

Scientists solve riddle of toxic algae blooms

Ed Struzik, Canwest News Service, Published: Tuesday, July 22, 2008

EXCERPT: After a remarkable 37-year experiment, University of Alberta scientist David Schindler and his colleagues have finally nailed down the chemical triggers for a problem that plagues thousands of freshwater and coastal ecosystems around the world.

Fifty years ago, no one knew what exactly caused algae blooms to appear on lakes and rivers. There was some evidence to suggest that carbon, nitrogen and phosphorous, which are associated with agricultural runoff and waste water, were responsible. But small-scale experiments weren’t able to show which were more important.

Schindler seemed to solve the problem when he and his colleagues conducted a number of groundbreaking experiments in northern Ontario in the 1960s and early 1970s. In a famous 1974 aerial photograph published by the journal Science, two portions of their experimental Lake 226 were highlighted. One side was treated with carbon, nitrogen and phosphorous. The other was treated with just carbon and nitrogen.

The side receiving phosphorous rapidly developed a huge bloom of blue-green algae. The side not receiving phosphorous remained in near-pristine condition.

Schindler’s latest series of long-term experiments shows that nitrogen removal completely fails to control blue-green algae blooms. He proved this by manipulating nitrogen and phosphorus levels on Lake 227 for 37 years. Nitrogen control, he found, only encouraged algae blooms.

more…

Conclusion? Phosphates and Nitrogen. Not global warming.

 

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41 thoughts on “Algal Blooms: Not Caused by Global Warming

  1. No pun intended–I thought that science was pretty well settled years ago. I thought that was why you can’t buy TSP any more.
    I must be too sleepy, I’ll read that again in the morning.

  2. But it doesn’t always deserve the blame for things that happen in our world

    I’d say it hasn’t been the cause of ANY problem. Only the THREAT of it has caused problems.

  3. Phosphates definitely make grass grow faster and greener. Used to drain graywater from the washing machine into the yard. Presto, the greenest lawn you’ve ever seen.

  4. If you read the article closely, you’ll notice that it states that phosphorus control need has been “settled” for a long time, but that NITROGEN control was always assumed to be needed also, but this experiment has proven that nitrogen control exacerbates the problem.
    Ergo the conclusion is that ONLY phosphorus control is needed, not nitrgoen control. This is the “news.”

  5. Ever notice that the ‘global warming caused it’ excuse is the default when whoever is doing the study it can’t find the real reason? It’s just easier to blame whatever on the currently popular bogeyman than to sort out the facts and find the real story.

  6. What a difference in the reporting. In an online magazine devoted to science, they latch onto global warming — what kind of science journalism is that? Then, the online edition of a Victoria newspaper, runs a Canwest News Service story that reports on the same phenomena and it gets right down to the practical matter of the steps needed to mitigate or eliminate the problem based on decades of rigorous study.
    The first sounds like an environmentalist’s press release, pitched to show the need for action to stop AGW.
    The second avoids the glitz and glame of what is currently fashionably chic and goes right to the heart of the matter, buffering lakes, streams, and wetlands from runoff.
    The first has got the sexy spin based on fantasy.
    The second is dull and boring mechanistic problem solving oriented, aka reality.
    No wonder science is in such a wretched state. Fantasy wins out over reality.

  7. Huh? Is this something new? As an Environmental Engineering graduate student, we’ve always talked about phosphorus controlling algal blooms in freshwater systems. I’ve never heard that nitrogen was the controlling factor in freshwater. The hypothesis is that this switches in the oceanic waters where N is more of an issue than P. Since it seems this study is dealing with freshwater ponds in Canada, I don’t see how it resolves the issue as to ocean waters and things such as Gulf Hypoxia…
    As to N fertilization, the major factor controlling need to remove nitrogen is the fact that wastewater treatment plants of older design only oxidize carbon to the Biological Oxygen Demand limits in the regulations. In a lot of US states regulations are being set at a Total Maximum Daily Load on a water body based on all discharging point sources, which is set by regulating agencies so that dissolved oxygen due to bacterial metabolism of C compounds doesn’t cause the dissolved oxygen in the water to drop below 5 mg/L O2 downstream of the discharge. TMDLs take into account all discharging sources to a water body.
    Less than 5 mg/L O2 will kill sensitive aquatic species. Trout are used as the economically important indicator for this. Older waste water treatment plants do not oxidize ammonia + ammonium (NH3+NH4+) to nitrate (NO3-), which, like carbon compounds, at a slower rate, exert an oxygen demand as it is oxidized to nitrate in a water body. Ammonia (NH3) is also highly toxic to aquatic organisms, and this is why most treatment plants try to oxidize or remove (as N2) nitrogen.
    Now, since cyanobacteria do like warmer waters and the solubility of oxygen is reduced as temperature increases, its not a total red herring to say that global warming, if it exists, could exacerbate the problem in eutrophic waters. BUT the temperature could go way high and cause few problems in a water body without high levels of nutrients.
    Good luck to everyone on the P problem, especially in Canada where they don’t have a Conservation Reserve Program or anything really like it. Here in the Midwest everyone is jumping to put every bit of land that corn can be planted on back into production due to the high prices. Controlling P runoff from soil (P is mainly associated with particulate matter) and agricultural practices is a huge issue that should be addressed, but there are no regulations on non-point sources. Unfortunately, best management practices that limit runoff cost money and take away acres that can be planted in crops.
    Sorry for the tome… this is a subject close to my heart.

  8. Leon Then, the online edition of a Victoria newspaper, runs a Canwest News Service story that reports on the same phenomena and it gets right down to the practical matter of the steps needed to mitigate or eliminate the problem based on decades of rigorous study.
    Huh. That’s decidedly odd, since the CanWest newspaper chain is fully on the AGW bandwagon, complete with a weekly enviro section (mostly stories ion how people do without cars, re-do their home/business with geo-thermal, write-ups on “green” local business, etc) and daily “suzuki suggests” boxes, as well as PR tips from a local PR firm whose head is on the Suzuki Foundation’s board (the firm runs DaSmogBlog).
    They even had Suzuki as guest editor last year for a whole week of AGW and anti-industry news.
    That’d be when I stopped buying the local Vancouver paper, since the choice here is CanWest blue-collar or CanWest white-collar.

  9. I know nothing about a link between AGW and algal blooms.
    I do know though that proving a link between phosphorous and algae says nothing about whether a link between AGW and algae exists or not.

  10. This matter has been a major controversy in Sweden for years on account of major algal blooms in the Baltic. Personally I think it is rather obvious. Blue-green algae (cyanobacteria) are the ONLY organisms on this planet that can fixate nitrogen and they are indeed the major source of nitrogen to the whole biosphere. Consequently trying to limit them by nitrogen control is obviously futile.
    Note that this does not mean that limiting nitrogen in effluent is unnecessary, most water plants (which incidentally includes a lot of that green scum) are indeed nitrogen-limited.

  11. At the risk of sounding the “science is settled” horn…
    I would surmise that the point of this post is simply to remind us all (and put it on record) that not everything bad or ugly in the world is the result of “AGW”.
    This is simply a pre-emptive counter to the inevitable march of the media (MSM) focusing on the Beijing Olympics and, no doubt, blaming China’s recent algal blooms on “AGW”.
    PS- When I say “remind us all” I’m coming from the point of a regular Joe/Jason… not a professional earth sciences kind of guy… (although I did get a “B” in an upper level Geology class at the UofA… I learned early-on to mutter on about “Pre-Cambrian” and “Apache Conglomerate”… ) 🙂
    Back to lurking.

  12. Sarasota County (Florida) has enacted a no phosphate ferilizing law. During our summer rainy season you cannot use any fertilizer with phosphates, I believe they cannot even be sold although I have not checked that out. This is to prevent phosphate run off during heavy rains. Nitrogen is not an issue.

  13. “It has become the new universal evil, replacing the threat of communism as the new global menace.”
    Interesting comparison, as the desired “cure” proposed by the greens is barely distinguishable from communism – i.e. governmental control of all aspects of our lives, and jailing people who dare vocalize differing opinions.

  14. RJ Hendrickson (21:19:43) :
    Phosphates definitely make grass grow faster and greener. Used to drain graywater from the washing machine into the yard. Presto, the greenest lawn you’ve ever seen.
    Back in ’82, during a long cold snap, my parents killed a 75 year old post oak that way. The runoff encouraged the tree to enter a growth phase during the middle of winter. I hated to see that tree go, did a lot of climbing in that tree as a kid. I also had to dig the hole through clay and sandstone for the new one…

  15. Patrick Henry (05:23:07)
    These dogmas are just a means to an end: Control by some elite. The Soviets were an oligarchy which just used communism for rhetorical purposes. Gore’s desire is for control by pseudo-intellectuals like himself. They have latched onto environmentalism because it gives them a lever to power, and the control of resources is power.

  16. ISTM that people are treating this asset as a problem.
    You should harvest the stuff. Probably contains lipids and valuable enzymes.
    You can read that as bio-diesel and stock-feed/fertilizer if it suits.

  17. Several factors contribute to the increasing incidence of freshwater harmful algal blooms (HABs), primarily caused by cyanobacteria (a.k.a. blue-green algae). HABs require sufficient:
    nutrients, sunlight, warmth, and quiescent, stagnant water.
    Global warming affects nutrients (increased runoff during more frequent heavy storms), warmth (increasing on average), and quiescent, stagnant water (more frequent droughts). Other factors also contribute to the rising incidence of freshwater HABs.
    See our book: http://www.epa.gov/cyano_habs_symposium/

  18. Dr Hudnell,
    That may be true, but there hasn’t been increasing drought, more frequent heavy storms, or increasing warmth (at least the last 10 years or so).

  19. The first article says that nutrient runoff is the primary cause of algal blooms, and they are exacerbated by higher water temperatures.
    The second article describes the specific nutrient responsible for algal blooms, but does not address the effects, if any, of water temperature.
    Exactly how is the second one intended to refute the first?
    REPLY: Algal blooms don’t happen without the chemical triggers, the point being that the temperature alone is not a trigger.

  20. bikermailman,
    Was it the phosphates, or the warm water warming up the roots and tricking the tree into thinking spring had arrived?

  21. The Global Warming scare will turn out to be the biggest fraud since the Y2K scare. Hansen and company will be ridiculed and their careers will be ruined.

  22. Keneth:
    Has it been proved then that AGW causes an increase in number and intensity of storms? I won’t be rushing out to read your book

  23. This article reminds me of something I read a couple of years ago about Poison Ivy. I think this is what gave impetus to my AGW skepticism. When will it end?
    Updated 5/29/2006 10:34 PM ET
    “WASHINGTON (AP) — Another reason to worry about global warming: more and itchier poison ivy. The noxious vine grows faster and bigger as carbon dioxide levels in the atmosphere rise, researchers report Monday. And a CO2-driven vine also produces more of its rash-causing chemical, urushiol, conclude experiments conducted in a forest at Duke University where scientists increased carbon-dioxide levels to those expected in 2050.”
    http://www.usatoday.com/tech/science/discoveries/2006-05-29-poison-ivy-study_x.htm

  24. Bernd,
    It’s too low a concentration and too sporadic to be useful. You can’t continually bloom a lake because the dying algae sucks up all the oxygen and nutrients suffocating or starving everything, including itslef. You have to filter it quickly enough to not get this problem yet keep a high enough concentration to be worth filtering (ie: about twice as much biodiesel can be produced as it takes to operate the filtration, purification, and pond maintenance combined).
    The idea is infeasible due to the small amount of algae that can grow before the lake is covered. Sorry, but the production is the wrong order of magnitude.

  25. I detect an error of omission.
    I won’t go far to say that it’s your intent to obfuscate, but it’s worth pointing out, from the first article you link to and then go on to mock:
    “It’s long been known that nutrient runoff contributes to cyanobacterial growth. Now scientists can factor in temperature and global warming,” said Paerl, who, with professor Jef Huisman from the University of Amsterdam, the Netherlands, explains the new realization in Science paper.
    “As temperatures rise waters are more amenable to blooms,” Paerl said.

    What I perceive in your post is to suggest that the whole lot of us who harbor concerns regarding climate change would place increasing algal bloom activity squarely and solely at the feet of warming without consideration for measurable, verafiable reality.
    Speaking for myself (I have a background in hydrology and watershed studies, fwiw), I’ve long understood nutrient (over)loading to be the primary culprit. I’m not alone. I don’t think it’s a reach worth ridicule to posit that increased temperature would help to facilitate algae’s propensity to feast on the ever larger nutrient buffet.
    It’s also worth offering for consideration that nutirent loading itself over and beyond what the systems can absorb and assimilate is not some isolated, happens-in-a-vacuum event, but a byproduct of flawed stewardship of our natural resources–whether intentional or not.
    Best,
    dmb

  26. I’ve been screaming for years that CO2 emissions are the least of our environmental concerns, and even if anthropogenic global warming were a concern, we should be more concerned about agricultural run off.
    There are rivers and streams in Mississippi (the state) that are so polluted with pesticides and fertilizers that the fish are unsafe for human consumption. These same streams feed into the Mississippi River, and eventually the Gulf of Mexico, causing that nice Gulf Dead Zone.
    <scaremongering>The quest for higher yields in farming will kill us all.</scaremongering>

  27. Global warming affects nutrients (increased runoff during more frequent heavy storms), ….. and quiescent, stagnant water (more frequent droughts).
    That is the kind of global warming causes everything statement that is regularly lampooned here.
    Otherwise, I concur with the statements about agricultural runoff being our most serious pollution problem.
    Resources are always finite (although somewhat elastic for governments). Putting (more) resources into one problem, necessarily means putting less resources into other problems.
    Global warming does cause algal blooms, not through rising temperatures, but by taking resources away from solving the algal bloom problem. A real inconvenient truth.

  28. Doesn’t sound very scientific, taking a study of cyanobacteria blooms focused on a small area of one country and extrapolating the results to “thousands of freshwater and coastal ecosystems around the world.”
    If all the worlds water bodies had the same watershed, climate and farming practices as northern Ontario, then they might have a point.
    This is bad science from academics with illusions of grandeur, exaggerating the implications of their findings.

  29. I want to reinforce what Zeke Hausfather wrote above. There is no contradiction between the two studies. Here is a quote from the article in Science, which anyone who follows the link can read:
    “It’s long been known that nutrient runoff contributes to cyanobacterial growth. Now scientists can factor in temperature and global warming,”
    Like many posters have pointed out, scientists have been aware of the role of phosphates for a long time. Mr. Watts, really, when you rush onto the Internet with stuff like this you only make it clear that real scientists generally do know what they’re talking about, and climate skeptics don’t.
    REPLY: The point is that GW is not the trigger, phosphates and nitrogen are. The story is about the clarifcation of the role of the trigger as being chemical in nature. Do you dispute it?
    So then, show me how global warming, by itself, triggers algal blooms. Be sure to show known examples of this cause and effect where it can be said with absolute certainty that “global warming caused this algal bloom”.

  30. There could be a link. If warmer temperatures make us sweat more, we wash our clothes more often, making more P laden runoff that causes…
    Nah. Rube Goldberg I aint.

  31. MarkW (09:44:04) :
    It was probably both. IIRC, phosphates in fertilizer encourage root growth.

  32. This is really interesting, considering here in northeast Florida the Department of Environmental Protection is requiring point sources (wastewater plants) and nonpoint sources (stormwater and ag runoff) to remove nitrogen prior to discharging to the St. Johns River to alleviate algal blooms. The cost of nitrogen removal will be close to $1 billion. I’m interested in finding out more about this study.

  33. DMB
    What piety. The old chesnut. If you don’t buy AGW you don’t care about the environment. That is nonsense. Most life forms benefit from a warmer environment. When I hear the word “stewardship” I know which bible is being quoted. Someone give me a bucket.

  34. Our editor (Anthony?) responds that “REPLY: Algal blooms don’t happen without the chemical triggers, the point being that the temperature alone is not a trigger.”
    However, unless my reading of the initial article under criticism is incorrect, it never argued that temperature an trigger algal blooms in the absence of a nutrient trigger, but rather that temperature can exacerbate the resulting blooms.
    I’ll admit that the news blurb is far from the model of lucidity (the Science paper that it is based on is much better), but it does say that:
    “”It’s long been known that nutrient runoff contributes to cyanobacterial growth. Now scientists can factor in temperature and global warming,” said Paerl, who, with professor Jef Huisman from the University of Amsterdam, the Netherlands, explains the new realization in Science paper.”
    Note that temperature “contributes to growth” rather than “triggers growth” which is an accurate way to phrase it, since higher temperatures are conducive to algal growth.

  35. Global warming affects nutrients (increased runoff during more frequent heavy storms), ….. and quiescent, stagnant water (more frequent droughts).

    Except there’s no evidence of increasing, heavier, or more frequent anything (storms, droughts, floods, take your pick).

  36. Drew Latta:
    The Gulf hypoxia issue is mostly due to freshwater intrusion into the Gulf. The density gradient is stratified by lower-density fresh water runoff, blocking oxygen getting to the deeper waters.
    This year’s dead zone is larger mostly due to the flooding of the Mississippi.

  37. That is how I interpreted what you said, in summary. If that is not your opinion then sorry for that.

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