EnviroLink Forum

there are 9 such mechanisms that I know of:
- when organic material rots, it produces methane and CO2... both are greenhouse gases. In permafrost areas, the top area grows stuff in the summers then freezes before it can rot. This builds up a thick layer of frozen un-rotted organic material from the centuries or even milleniums of permafrost. Melt that permafrost and bang-you have thousands of years of organic material suddenly rotting.
-soda pop contains CO2 to make it bubbly. Try this experiment sometime: add some hot water to cold pop and see it fizz up. Water will hold a variety of gases including oxygen that fish breath with their gills. Cold water holds more gases then warm water. Methane is a rather heavy gas so water with methane in it sinks to the bottom of the ocean. Also, geologic structures release methane which stays in the water instead of going into the atmosphere. Deep water is very dark so has no sunlight to warm it. The cold water is heavier so stays at the bottom. If the oceans do warm up, they release some of their methane and CO2 and any other gases they have.
- Ocean water flow is based on a combination of inertia (like a turning wheel wants to keep turning) and the locations of water heating and cooling. If they change the path they flow in even a slight amount, they disturb water that has been sitting in place for centuries. This cold water then gets pulled to the surface under areas of water warming to replace the warmed water that is flowing away from the warming area. Of course this means the water is warmed quickly and pushed to the surface then send around the globe near the surface to warm even more. Back to the previous item... any methane and CO2 it has is released. Weather changes and water level changes and sources of cold water like melting glaciers on Greenland or Antarctica can all impact the path of the ocean flows.
-Warmer air can hold more liquid vapors then colder air. The air is mostly heated by the surface of the planet. This means that a warmer planet will have more low clouds that keep the surface warm at night but not more higher level clouds that reflect most of the sunlight back into space (because the upper atmosphere is not being heated directly by the earth but rather by the cold arctic air mixing during movements of the jet stream... dry air mostly). Warmer oceans and warmer dirt will make more of these clouds that act like blankets at night and thus have a net warming effect.
-snow reflects sunlight back into space as visible light (CO2 does not reflect visible light back down... only infrared light caused by hot objects called "black bodies" for a reason). Warmer weather means the snow comes later and melts earlier meaning less sunlight is reflected back into space and thus more warming can happen in the longer non-winter months

I can detail the rest if you like but those are the main ones... heat the planet and the planet causes even more heating as a result.

edit: I forgot to explain "tipping point"... when the Earth causes more warming increases from the above mentioned things then the speed at which we reduce the heating (either natural reductions of variations in weather or sun activity or changes in how we affect the land), then the heating will happen faster and faster due to the above things. The point where it will heat no matter what we do is this "tipping point".

No.

What is going to suddenly change?

What mechanisim will it be that alters?

Plants rot and give off CO2 and methane etc as allways. What point will need to be achieved to get a positive feed back loop?

What temperature rise will we have to see for this catastrophy to happen?

What mechanisim will do this tipping? Why will it do it at this time?

The IPCC says that the worst case scenario is for a 6.4 degree c temperature rise by 2100 but this, I think, has been revised down to a more reasonable max of 3.2 degrees. That would give an expected foot or so of sea level rise. Do you have information that the IPCC has it wrong? They don't talk of a tipping point resulting in positive feedback.

The ability to recvoer from the trend.



There are a few possible, but once one is reached it is probable more will follow. The plant surviabilty range is the most likely as plants do not change range as quickly as animals and will be more vulnerable.



Not really a known since we have never seen a massive die off to be able to gauge the process, but there is a lot of carbon in the cycle that can be released.



Not really known, which is the big concern. Just like playing Russian Roulette, you do not know when it will happen but you do know that playing long enough will see a nasty result.



Still not sure what you are trying to ask. The initial fialure of a few plant species and that impact on the other plant and animal species will cause additional stress on the survivors, which will in turn cause more failures to survive until there is a major extinction or something happens to cahnge the temperature trend that does not also cause major extinctions.



Because the situation has been set for this path and we are pushing farther and farther down it.



So you were not asking about the tipping points related to the article, you were asking about other tipping points?

_________________
With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none”
Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."
Albert Einstein

I see the confusion. These are different tipping points than the article referenced. These are tipping points for a jump in temperature, which would also bring about the extinction tipping points discussed in the article. The extinction tipping points may be reached before the temperature tipping points.

_________________
With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none”
Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."
Albert Einstein

http://www.livescience.com/8599-extinct ... table.html

When ecologists model the decline of species (a computer simulation of sorts), they see tipping points — sets of circumstances that make extinction all but certain.

To date, mathematical modeling has revealed a few statistical harbingers of tipping points. Right before a system reaches the point of no return, it goes through a phase called "critical slowing down." That phase is the statistical equivalent of the gut feeling you may experience right before a canoe tips over or a rollercoaster makes a plunge: that the system can no longer recover from perturbations in the environment (like your last-minute attempt to balance the canoe), and a dramatic change is imminent.

In nature, those perturbations might be small changes in temperature or precipitation, or simple normal fluctuations in how many offspring a species produces.

"The ability of the system to respond to perturbations, to these little nudges, is diminished," study researcher John Drake, an ecologist at the University of Georgia, told LiveScience. "So lots of little nudges accumulate, and that's what we call critical slowing down."

To find out if critical slowing down can predict extinction in real-world ecosystems, Drake and Blaine Griffen of the University of South Carolina used millimeters-long crustaceans called water fleas. The tiny algae-eaters were split into two groups and fed until their population stabilized. After about 150 days, the researchers stopped feeding one of the groups.

_________________
With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none”
Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."
Albert Einstein

I should explain "positive feedback loop". When I took "industrial instrumentation technology" we would design control systems for various industrial processes. An example everyone knows about is the float control in a toilet tank. As you add water, the float rises up and operates a valve to slow down the water and eventually stop it. When you flush, the level goes down and the float drops and the valve is turned on again to fill the tank. The level of water is called the process. The float and the valve is called the feedback loop. When the level decreases, the water flow increases which is the opposite or a "negative" reaction. And vice versa, increased level results in decreased flow, the opposite reaction. If the valve was turned upside down so lifting the float increased the water flow, the tank would overflow because the float would be trying to add more water as the level rose... a positive feedback. Similarly, if you flush, the float would fall and decrease the water from decreased level... two negatives equals a positive so yeah it is a positive feedback and the tank will just run dry. As you can see, a positive feedback loop will cause the process to go to extremes but a negative feedback loop will control the process to reach a steady state.

I never imagined anybody was considering the equilibrium of new species formed to species going extinct. The extinction rate is very fast so to stop the decline in species numbers, we all have to believe in Creationism to make new species faster then the millions of years evolution requires. As for a positive feedback on extinction, I think you have to look at rats. Norway rats have caused the extinction of many species of rodents. People were not noticing because rodents are pests. Many small predators also became extinct before being cataloged because they could not kill and eat rats and the smaller rodents they relied upon were killed off by those rats. Then we started poisoning rats and ground squirrels and to our surprise, we lost countless insects, amphibians, and reptiles that inhabit the holes they live in. We narrowly saved the Black Footed Ferret but the black plague is killing them and their prey... another burrowing rodent. Many birds are now extinct or almost so because they relied on holes of animals or prey species that went extinct. A new poison for grasshoppers was introduced that stayed in the plants. Drastic reductions in rodent numbers resulted and surprise, surprise... birds of prey declined rapidly due to not having enough food to produce eggs (this included grasshopper-eating birds). Thankfully that pesticide has been banned in most countries but it was too late to stop the decline in some species... they are now declining due to inbreeding due to low numbers. This is only prairie rodents I am talking about... I think tipping points have past for many ecosystems already. Another factor is "bush meat" in many poor countries... as the easy-to-catch species get eaten, the endangered species become the next menu item. We need to stop farmers from growing cotton to growing grains and animals to keep food prices down to save wildlife... not going to happen. The tipping point is long past on that issue in many parts of the world. By the way, the easy-to-catch species I was referring to are the various rodents who (surprise) have largely become extinct due to poisoning efforts by farmers... a tipping point long since past.

So all these tippiing points are unknown airy predictions with no actual modeling or physics involved.

Might as well say anything. We are all doomed because of the great tipping pointed monster which will steal our souls....

No, but because that tipping points are by definition an unknown as we have never seen them the science indicates the probabilities of their range. Without seeing the tipping point occur and documented in certain circumstances one cannot give specifics and even when the points have been documented the variables are still limited to the levels for any prediction. That is why predictions of specific changes always include the caveat of all other things remaining the same.

_________________
With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none”
Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."
Albert Einstein

the very real hard data is that the earth is heating up and that animals are going extinct very fast. Without a way to measure ALL the causes of such heating and ALL the causes of extinction, we cannot determine if the causes are not justified for the speed of the reaction in heating rate or extinction rate. If we did have such causes and effects carefully measured and find them unjustified, the difference would be proof of a tipping point being past. Using graphs, we can mathematically isolate waves of causes and then see if new sources are being added. The math to do this is about 10 times as hard with each new source so our current computers can only isolate about 3 or 4 or the main causes. Isolating annual influences and solar cycle influences (11 year cycle), they have found a steadily increasing factor. This factor could be the increase in CO2 but the curve does not exactly match so something else is at play. This might mean we are past a tipping point or it could mean we do not yet understand all the inputs (just sticking to the heat thing as species extinctions have billions of possible tipping points rather then a handful) As you can see, you are asking the impossible of exact proof without being past a tipping point and looking back in time. My point is that this increased rate (both earth temperatures and animal extinctions) is alarming and impossible to slow down within our lifetime so if we do find a tipping point before it passes, we will not be able to do anything anyways as it takes us years for changes to come into effect and years more for that effect to influence the trends.

I see this as very similar to the cigarette causing cancer debate for more than the reasons the same fallacies are used to confuse people.

The question could be posed about how many cigarettes will cause lung cancer. It seems on the surface to be a simple question and it is a very simple question that relies on a lot of very complex variables to give an answer. The fact is there may be a cancer rleated to smoking in a very short time frame or a very long time frame even with the same number of cigarettes consumed in a day. The other variables come into play in the final determination of when the effect will be exhibited. A probability range can be worked out based on larger numbers of people used as data points, but no definite determination can be made for a specific person to predict which cigarette will be the tipping point into cancer. We do not have a large number of planets to use as data points so we cannot create a similar probability range. Even if we did, the key is the one planet on which we live that may be one of the really early cases and if so we have passed a tipping point before we expect it and we are in trouble.

The only real solution to be safe is to assume there is no time to waste in mitigation as if this is the case and we wait we may not have the chance to attempt mitigation in the future.

_________________
With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none”
Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."
Albert Einstein