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.

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).

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.

>> If you don’t buy AGW you don’t care about the environment.

I did not say that. At all.

Best,

dmb

It was probably both. IIRC, phosphates in fertilizer encourage root growth.

Nah. Rube Goldberg I aint.

“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”.

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.

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.

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>

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

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.