That is why I call these people watermelons. They may be green on the outside, but underneather they are all commie red.

That was funny!

They’re really coming out of the woodwork today.

Huh?

Sorry, dude.  The first two statements are entirely compatible.

The ocean current they are referring to is our familiar Gulf Stream.  It is driven by a “saline pump”, in which the warm waters that are carried towards Europe sink as they are cooled.  As they descend, they flow back towards the equator, creating a “heat pump” that pulls heat from near the equator and conveniently deposits it at higher temperate zones.  The pump depends on the salinity of the water being high enough.  If the salinity is reduced too much, the pump shuts off.

This isn’t wacko commie talk, it’s just the physics of ocean currents, and pretty basic stuff by oceanographic standards.

The second piece of the puzzle is the rapid melting of glaciers during the last century in North America, Greenland and the European Alps.  This rapid warming is decreasing the salinity of the oceans, resulting in a reduction in the strength of the Gulf Stream “heat pump”.  Melt enough ice off, and the pump shuts down… then we get a rapid cooling in Europe and a mini-ice age.

Just because two statements appear at odds to a layman, doesn’t mean there’s anything wrong with science.  It could just mean you need to educate yourself a bit more before jumping to conclusions.

Finally most of the warming is unrelated to human activity.  You could cut human-generated green house gases to zero, and you would still get a warming trend.  As I’ve pointed out before, the biggest correlation with global mean temperature is solar activity, and not greenhouse gas emissions.

There may be and likely are problems with releasing so many greenhouse gases, but the biggest problem is likely something other than just global warming induced by the greenhouse gases.  As an example, part of the CO2 released into the atmosphere is getting absorbed into the oceans, increasing its acidity.  This wasn’t anticipated by scientists, and is a good example of why we need to be cautious about carte blanche modifications to our atmospheric chemistry.

[...] Rob points out the ridiculous credibility problem global warming folks have. [...]

Carrick: I defer to your apparent expertise in this area.  I do have one question, though.  Has anyone ever observed this “saline pump” fail?  If so, what happened when it did?  Maybe this is extrapolation, which isn’t the same as actually observing a cause and effect relationship manifest itself.

Now why are Carrick’s wise words relegated to the “Comments” section, while gilbyguy’s drivel is front-paged?

robert108:

Has anyone ever observed this “saline pump” fail?

Indirectly ... yes (via prehistorical geophysical data).

Let me put it this way though.....

The Gulf Stream warm-ocean current and the corresponding cold subsurface currents are observable facts.

The physics behind the mechanisms which drive this current are extremely well understood.

It is an extrapolation from the current ocean data to infer what would happen if the salinity of the ocean in the Atlantic were to drop.

This extrapolation is very different from e.g. a linear extrapolation of data (an operation that almost always sucks if you don’t have a physical model), because the extrapolation is being performed directly from a physical model.

If anybody wants to challenge the physics, good luck.  We’re talking Newton’s laws of mechanics applied to fluids, here.  From my understand of the relevant fluid mechanics, I am quite confident with the veracity of the statement:  “If the salinity of the oceans drop, the deep ocean currents will either shut down or at least operate less effectively to transport heat from the equator to more temperate latitudes.”

The caveat I felt post hoc that I should have raised in my comment is that we don’t know for certain what will happen if the salinity drops low enough to shut off the pump.

Historically, we know that that the drop of salinity caused by global warming has led cooling of Europe.  In this case, I think the jury is out.... it could be that the resulting increase in Greenland’s and Europe’s ice fields will rapidly increase the salinity of the ocean enough to fully restart the pump.  That is an alternative scenario the doomsday’ers won’t bother mentioning…

Do they know why the ocean is absorbing all that CO2 and are we screwed if it stops?

Dave:

Now why are Carrick’s wise words relegated to the “Comments” section, while gilbyguy’s drivel is front-paged?

Let’s agree to be nice, Dave.

Personally, I have no problem with people asking questions and raising issues.

At the risk of sounding like a school teacher, but I mean this sincerely, Gilbyguy raised an important question that I’m sure a lot of other people have wondered about too.  My reply is buried, simply because I haven’t bothered to write a front page article on it.  I’m kind of busy right now or I might ( my local time is 11:05PM & I’m south of the equator, can you guess where I am?)

One of the things I really like about Rob’s blog is that lots of people from different walks of life frequent it.  This gives a lot of fresh perspectives on the issues of the day, and for me at least is an enriching experience.  Whether Gillyguy agrees with my comments, at least he has gotten (hopefully!) a coherent explanation of what “scienitsts really believe” as opposed to environmentalist propaganda.