Will human carbon emissions kill off the world's coral reefs by 2050?

Question

I'm talking about atmospheric CO2 causing ocean acidification, not global warming. The fact that we're causing atmospheric CO2 concentrations to increase which causes ocean acidification are 2 facts which I hope we can all accept.

"Modeling ocean chemistry under a range of atmospheric CO2 levels, an international team of researchers led by Ove Hoegh-Guldberg found that a rise of CO2 levels to 450-500 ppm would trigger major shifts in marine diversity, with present coral reefs giving way to "thermally tolerant and fast-growing corals". Under a scenario whereby atmospheric CO2 levels exceed 500 ppm by 2050, the researchers predict large-scale losses of corals and a 50 percent decline in marine animal species."

CO2 levels are currently increasing at a rate of nearly 2 ppm per year

http://en.wikipedia.org/wiki/Image:Mauna_Loa_Carbon_Dioxide.png

AT 384 ppm now, we'll reach 450 ppm by about 2045 and 500 ppm by 2070.

Is avoiding this reason enough to reduce GHG emissions?

Full story here:

http://news.mongabay.com/2007/1213-corals.html

My scenarios assume a constant rate of increasing CO2 emissions, the researchers' scenarios assume that the rate continues to accelerate as is currently the case. That's why they get 2050 where I get 2070.

Tomcat - you're ignoring the fact that we're already seeing significant bleaching in coral reefs. You're making the same mistake of looking back at geologic times while ignoring modern data.

An important distinction is that CO2 does not directly harm coral reefs. It's acidifying the oceans which is what harms the reefs.

Plasma - my mistake. I thought Science magazine would contain science. I didn't realize it was a tool of propaganda.

LMAO!

Tomcat - according to the IPCC (via your link), the 2 greatest threats to the Great Barrier Reef are increasing SSTs and ocean acidification.

Jim - either educate yourself on coral reef bleaching (Tomcat's link is a good start), or stick to geology.

Mikira - "We have already developed ways to lower our emissions, so why aren't they using that technology?"

A better question is - why aren't we?

How fast can we reduce emissions? Politicians are developing plans to reduce them by 50-80% by 2050.

Answer 1

Over long time scales, say a few thousand years, the ocean is well buffered with respect to changes in atmospheric CO2. As more, or less, CO2 is in the atmosphere, more, or less carbonate-bearing minerals dissolve into the ocean. In the case of high CO2, as the carbonate dissolves the alkalinity neutralizes the acidity from the CO2. This is why coral reefs could thrive in a world with an atmospheric partial pressure of CO2 of 2000 ppmv. The ocean wasn't more acidic, it still had a pH of around 8.3 (the endpoint of the titration of carbonic acid with carbonate), but it contained marginally more bicarbonate (I think like a factor of five or so but I am too lazy to do the calculations right now). Higher bicarbonate is not toxic, as far as I know, however the same is not true for pH, which is why what is going on now is so critical to marine life.

Over short time scales, say 100 years, the ocean surface is poorly buffered with respect to changes in CO2. There isn't time for carbonate to dissolve to neutralize the extra acidity from the carbonic acid. In this case the additional carbonic acid *will* acidify the surface layer and pH will drop (this has been observed and was the subject of a recent scientific achievement award to Richard Feely from NOAA PMEL). All ocean life is highly adapted to live in water with pH around 8.3, since over geologic time scales the ocean pH doesn't vary (because of the buffering effect of carbonate (there is a lot of dolomite, aragonite, calcite etc. around)). A change of pH of a few tenths of a pH unit is sure death for a lot of critters in the ocean.

Anyone who claims that high CO2 in the past implies things will be hunky-dory in 2050 simply is ignorant of basic aquatic chemistry. To those people, I highly recommend chap. 4, Dissolved Carbon Dioxide, in Aquatic Chemistry by Stumm and Morgan.

Answer 2

You're right untitled. Although Gore probably personally infected these reefs, I have been following some of these type issues. You've probably read in the past how antibiotics and steroids used for livestock contaminate the water supply and lead to abnormal development and diseases in both the fish, etc, and in humans drinking the water? Well now they are finding the same stuff in deep sea fish. Some species are dying out because the steroids makes the change gender or become sterile. That's how thoroughly we've poisoned our own environment.

Answer 3

That could be one of the reasons that the oceans are "acidificating", but there are probably others. I've heard that since the ethanol boom, there is a big dead zone in the gulf of mexico just outside of the Mississippi river. It appears that all the extra chemicals that farmers are using to grow corn (for ethanol) has been running off into the Mississippi River water shed, and consequently flowing down the river and into the Gulf. I'm sure there are countless other examples of the oceans getting polluted in other ways. Acid rain anyone???

besides, I thought that some of these coral reefs were becoming quite endangered already, right?

Answer 4

It sounds like a good reason to lower our CO2 emissions. But I'm still worried about the fact that developing countries, such as China not having to do anything about any of the emissions they put into the air. That is one of the things that angers me the most about all of this. We have already developed ways to lower our emissions, so why aren't they using that technology? Or building wind turbines? Or etc. etc. etc.

And if we do successfully lower our emission of CO2 here in the US, will that offset what the third world is pumping out?

Do you have an estimate on how fast the whole world can get on board with cleaner technology for all of their power plants and industries?

Basically how fast can we turn our CO2 emissions around?

Answer 5

First you say that you are talking about pH and then you talk about bleaching which is related to temperature. I notice that your source didn't try to suggest that pH levels would change. They left it vague as all your claims are so that the ignorant just go along. In fact corals live in the ocean at a particular temperature range. Those living at the upper extreme of the lolerable range will suffer with warming. Those living at the lower temperature will thrive. In other words, people with an agenda, find corals in warm water that are stressing due to temperature and are bleaching due to lack of algae and they pretend that this extends to corals everywhere. It is nonsense, and a lie and you should know better. As to the increased CO2 and the increased acidity, I am willing to bet that it is a nonproblem. These political hacks that you refer to as scientists are not believable and just another example of the global warming scare industrial complex that has arisen to absorb the billions thrown at them as long as they keep trying to scare people. Tomcat is right. The extremely high CO2 levels did not prevent corals from thriving and I have examined numerous limestones as a geologist that formed from corals as evidence of that.

Answer 6

No, at the peak of the Jurassic CO2 was over 2000 PPM and the Cretaceous CO2 levels remained above 1000 PPM, and there were massive reef systems that thrived during that period. There is no evidence that coral species have adapted to the low CO2 environment that they currently live in, considering the fact that they evolved in an environment with CO2 at much higher levels.

http://mysite.verizon.net/mhieb/WVFossils/Carboniferous_climate.html


EDIT:

Acidification is one possible cause, but it is primarily because of temperature and or silt runoff.

EDIT:

LMAO..... Dana the IPCC has no credability, they have been caught lying one to many times.

EDIT:

Gwen, one of the greatest threats to the great barrier reef is runoff from agricultural activities in Australia. And as I have said many times the oceans have been cooling for several years, including the largest reef system on the planet. You and Dana are some Koolaid drinking little shisters aren't you?

http://blogs.news.com.au/images/uploads/GBR_SSTs_thumb.gif
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http://sitemaker.umich.edu/gc2sec7labgroup3/pollution


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Answer 7

No.

But now you gave Al Gore ammo to tax us even more for coral that 90% of the global population will never see or experience and mostlikely never will since they will get taxed more and never have enough money to go on a vacation to check out these corals.


Tax has a death grip on US citizens

Answer 8

Considder this. carbondioxide is such a bad thing? what do trees breathe in the day time, and convert to oxygen? Yep, they breathe carbondioxide in, and they in turn for our waste breath and emissions, clean pure oxygen. Why do people want to cut down on the air that trees use to give us oxygen?

Answer 9

No. Don't be silly.

We live in an ecosystem that constantly recycles elements. It's a self sustaining system. All lifeforms on this planet break down the compounds and they get reused. It's a wonderful system.

Try reading up on some science instead of reading all that propaganda junk. You might learn something important instead of getting yourself all worked up over nothing.

Answer 10

It's not only a tragic loss of an incredible ecosystem it's an indicator of the greater problem of loss of calcium carbonate production in the oceans.

Tomcat, think about what you said about "but it is primarily because of temperature and or silt runoff"
Temperature is one factor yes, but silt? Increased silt from an isolated Pacific atoll? Think about that one Tomcat.

EDIT
Tomcat, the Great Barrier Reef is but one reef in an ocean of dying reefs. The reality is that silt is not the probelm on the GBR. http://www.sciencemag.org/cgi/content/summary/316/5825/678?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=%28reef+AND+bleaching+AND+acidification+AND+silt%29&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT