Climate realist

Overview

The problem of raising an alarm is that if the people are not prepared it induces panic. I am not an alarmist, I am a realist. 

I am not taking the position of climate change denial, I want the real picture. This is not an attack on McPherson, Carana or anyone else. They have provided important information that everyone should be aware of I just believe the pendulum has swung too far. If the people believe they are defeated, then they will not adequately prepare.

Before I begin I am going to re-iterate I believe a lot of people are about to die from climate change effects, and that we have gone over the edge of a tipping point. The effects will be multi-generational. But, I want to know exactly what my kids will be facing. 

If I had a mechanism for doing so I would prefer to hide this article, and only show it to certain people. I am doing this for the people who already understand the seriousness of the situation and are now taking stock of the future for their family. To have a will to overcome adversity requires faith that there is some benefit in the effort. So I am going to argue, this will be a massive blow to humanity, but it is not an extinction event. 

Smoothing the extremes

To start I am going to look at an article at Arctic News. The article's intent is to alarm, and that is a good thing, for the general public, but it is not scientific. 

The spreading atmospheric methane global warming veil is raising the temperature of the lower atmosphere many times faster than carbon dioxide does, causing the extreme summer temperatures in Australia and the United States.

I find it difficult to imagine that the hydroxyl radicals in the tropo/stratosphere over Australia, being overwhelmed by methane from the tropics this early in the game. The warming in Australia is a result of carbon dioxide, not methane (yet).
This link http://methane-hydrates.blogspot.com.au/2013/12/noctilucent-clouds-further-confirmation-of-large-methane-releases.html has the methane in the stratosphere coming rising from Antarctica, not transferred through the atmosphere.

Much of this methane is coming from the subsea extreme methane emission zone (Enrico Anomaly) at the transition from the Eurasian Basin to the Laptev Sea which is sourced at an estimated depth of some 112 km in the upper asthenosphere in the Earths mantle (Light 2014). The Earth's mantle methane is being formed in an Arctic "graveyard of subducted plates" by the reactions between the subducted water, carbonate and iron (2) oxide at depths between 100 and 300 km (Light 2014). 

The claim is that the emissions are actually coming from methane created 100 - 300km below the surface. That is, the methane is abiotic, not organic, and resulting from geological chemistry and that methane has been locked away for millions of years. The article goes on to state that this is resulting from fault seals being warmed. The fault is the Gakkel Ridge 2300m - 4500m deep which is in the Eurasian Basin. The warming is beginning to affect the shallow sea beds, it is unlikely to be melting the hydrates at that depth yet. Hydrate melt temperatures are affected by depth, the deeper you go the more the temperature has to rise. From (here)

At 2300m your water pressure is 23220kpa (link). From the above chart the water temperature would have to be 19.5°C to convert the hydrate to gas at the higher points on the Gakkel Ridge. From this report "In 2012 and 2013, the warmest Atlantic Water temperatures (~5°C) were observed in the Barents Sea." So it is not possible that "fault seals" are being melted.
The more likely culprit is Earth tremors and quakes. But methane at those depths would recrystallize.

So what is the origin of the methane? It is organic material held in the sub sea permafrost, as a result of the Azolla event. That event was sufficient to reduce the global CO2 concentration a total of 2850ppm. That's a lot of Azolla, and it has been frozen down there for 49 million years. Well not entirely, but more on that later.

The 1850 ppb methane cloud will only arrive at the south pole 8 years before mantle methane derived from about 280 km depth (ca 2050) (Light, 2014). 

It is not possible that the methane cloud is going to go through the tropo/stratosphere all the way, with no dispersion, and unmolested by hydroxyls and arrive at the South Pole still measuring 1850 ppb.

The cold Arctic air will then be confined to the Greenland Ice cap and the hot Arctic air with its methane will flow south to the United States to further heat up the Gulf Stream, setting up an anticlockwise circulation around Greenland. 

If anything, the Thermohaline circulation (THC) will be shutdown by fresh water coming off Greenland. What the article claims is that the East Greenland current to be shutdown and reversed. This is very unlikely. In the fix it article, a huge volume of fresh water is going to come off Greenland. That water will not mix with the Atlantic ocean, but the chances are it, rather than the THC, will be flowing into the Arctic.

If this process continues unchecked the mean temperature of the atmosphere will rise a further 8°C and we will be facing global deglaciation, a more than 200 feet rise in sea level and a major terminal extinction event by the 2050s.

Dr Wadhams puts the global warming effect from the methane hydrates at .6C. Combine that with 3C by 2050 gives 3.6C (http://preppingforexile.blogspot.com.au/2014/06/the-timeline.html). At one point the article stated that 8C was an extinction event. If that was true there would be no humans at all, right now.

This correlation which goes back to 420,000 years ago shows that when the mean methane content of the atmosphere hit 1.79 ppm/v (1790 ppb) it produced a (delayed) methane eruption induced atmospheric temperature of some 20°C.

During the Permo-Carboniferous period CH4 levels were at 12,000 ppb (link) with an atmospheric temperature of 20°C. You can see the temperatures changes in the Permian in the image below.

This would indicate that temperatures are going to go up. However, 12,000 ppb is a lot different to 1790 ppb.

The United States and Canada must now cease all their fossil fuel extraction and go entirely onto renewable energy in the next 10 to 15 years otherwise they will be guilty of planetary ecocide - genocide by the 2050s. 

This is not simply not possible. You have to green logistics http://preppingforexile.blogspot.com.au/2014/05/logistics.html and you have to prepare for thermal events http://preppingforexile.blogspot.com.au/2014/05/body-temperature.html and the production of food is going to trend towards being generated in closed environments.
It is going to require an increased load on the network, and it will require a constant load that renewables do not offer. Throwing everything at converting to renewables without a realistic view of what the load will be will result in no funds to build the systems actually required.
Accusing them of genocide is inflammatory and dangerous. We are all individually culpable. If we did not participate in the system, the system would change.

...global warming has heated up the oceanic currents fed by the Gulf Stream flowing into the Arctic, causing massive destabilization of the subsea methane hydrates and fault seals and releasing increasing volumes of methane directly into the atmosphere (Light 2014).

There is no evidence of fault seals being affected by the gulf stream current. This is impossible, here is a temperature profile of the arctic ocean.



Here is the topography.



A simple melt event would not result in this effect as the fault is still covered in sediment. The temperatures are no where remotely close to what it would take to melt hydrates at those depths. From this link, the methane clathrate stability curve shows that at the depth discussed it the temperature would have to exceed 20°C for the methane to be released as gas.

The other issue people raise is that of East Siberian Arctic Shelf (ESAS) hydrates. Given the above chart you could draw the conclusion that in the shallow waters the hydrates could exist, and that a small amount of warming would convert them into gas. This is a crucial point that is reinforced by NASA (below), due to the self-preservation phenomena of methane hydrates, it is true they could exist. The problem is that throughout much of the ESAS methane hydrates could never have formed in the first place. There is not enough pressure. The average depth is 45m, the following chart (link) shows the formation requirements for methane hydrates.

That is not to say that methane is not being emitted from there, as explained earlier it is just not from melting hydrates (more below). This may seem like splitting hairs but it is important in the context of global warming. If the warming causes a release then there is a potential for a sudden release of massive quantities. That may still occur, but it won't be from melting hydrates in the ESAS.

So the emission event as discussed in the article would have to be from an earthquake.

Linear zones of extreme methane emissions on Figure 7 that occur at right angles to the trend of the Gakkel Mid-Ocean Ridge in the Eurasian Basin are probably methane that is deeply sourced and has entered shear fault systems, some of which represent plate boundary zones (Carana 2014, Light 2014). 

Many of these emissions coincide with Earth tremors/quakes at the same time.

The high equatorial concentration of methane will be the reason for the extreme "El Nino" this year and the heating extends eastwards to the Gulf Stream enhancing its energy in a giant feedback loop (Figure 11a from Harold Hensel, personal communication, 2014). 

Ocean temperatures in the Kelvin wave is the direct driver of El Nino, not atmospheric methane. Here is the actual problem.

A major feedback mechanism is the heat trapping Methane Global Warming Veil sourced from the subsea Arctic methane hydrates which has blanketed the whole of the United States as far south as the Gulf Coast (Figure 9)(from July 2013 - Methanetracker.org). 

The source of the methane over the United States is the United States itself. (link)

A second feedback mechanism is caused by the Arctic Ocean ice and Arctic region permafrost which is being degraded severely by atmospheric temperatures around 20°C above normal, especially in Siberia and Alaska.

The average anomaly has been 5 - 7°C, 20°C was a spike. Not to say that 20°C is a good thing.

Cenozoic pyroclastic volcanoes also occur on the west end of the ESAS, so destabilization of shallow methane hydrates is probably also opening deep seated, verticle fractures which will allow mantle methane to rise up into the atmosphere

If they are deep seated then it is unlikely that they will be under immediate threat as depth affects the freezing point of methane hydrates. Again, due to the physical properties there can be no shallow hydrates created in the ESAS.

The massive hydroxyl hole in the atmosphere over Indonesia and the west Pacific also allows the shallow Methane Global Warming Veil to rise vertically into the dense equatorial stratospheric methane belt increasing its concentration (Figure 10). This is probably the source of the El Nino heat build up in the Pacific which is likely to occur in the Summer and Fall where the winds over the warmer ocean have shifted to the east 

There does not appear to be a dense stratospheric methane belt.

The El Nino build up of heat in the Pacific is due to Easterly trade winds transferring atmospheric heat into the ocean. The article goes on to state;

The North Atlantic has the largest zone of high salinity on Earth due to extreme evaporation caused by pollution clouds pouring off North America (Figure 14)(Ametsoc, 2001).

The North Atlantic salinity is due to hot dry air coming off the Sahara desert.

I won't go through the rest of the article. I think the intent is right, but some of the assumptions are wrong. The conclusion that;

Humanity's absolute incompetence and stupidity caused by our fatal addiction to fossil fuels in assessing and dealing with the impact of global warming and climate change can only lead to our total extinction in the near future. When it is all over by 2050, Aliens are sure to arrive and pick their way through the debris of our flooded cities when they come to terraform the Earth to their own liking.

Total extinction in the near future is not a foregone conclusion. As some of these processes will take time to play out. To me, this time factor is absolutely critical. The time before panic sets in is the time required for preparation.

For example,  here is another article.

After the snow begins to melt, and because shallow melt ponds have an albedo of approximately 0.2 to 0.4, the surface albedo drops to about 0.75. As melt ponds grow and deepen, the surface albedo can drop to 0.15. The ocean reflects only 6% of the incoming solar radiation and absorbs the rest. Furthermore, all the heat that during the melt went into transforming ice into water will - in the absence of ice - be absorbed by the ocean as well.

No mention is made of the Zenith angle. That is the angle of the sun, as the sun's angle increases so does the amount of radiation reflected. You don't get much of a reflection when you look directly down at a still water surface. The more you increase the angle the more reflections you will see.
In the Arctic the sun is much lower in the sky. Here is a table of the albedo affect on various substances;

(source). The values stated in the article (0.15) are at the very tail end of the albedo of open water with a large Zenith angle (0.10 - 1.00). Under those circumstances the figure of 6% reflection is invalid. 
No mention is made of the increased reflection/dispersion of the sun's radiation through the atmosphere at those angles. When the sun is at an angle, it has to pass through much more atmosphere before it hits the target. As discussed here, that is not a simple issue. 

As the The solar zenith angle (SZA) increases, the daily dose decreases, however the length of the day is longer in summer, which somewhat balances it out. Not completely though.

Hydroxyl generation

With reduced Hydroxyls, what will remove the methane from the atmosphere? How, can there be any confidence that the methane will not stay in the atmosphere. That would result in runaway global warming as forecasted.
It pays to look at the various forces that create Hydroxyls and a powerful one is lightning. 

Here, we show that the reaction of electronically excited nitrogen dioxide with water can be an important source of tropospheric hydroxyl radicals. Using measured rate data, along with available solar flux and atmospheric mixing ratios, we demonstrate that the tropospheric hydroxyl contribution from this source can be a substantial fraction (50%) of that from the traditional O(1D) + H2O reaction in the boundary-layer region for high solar zenith angles. (link)

For every one degree Celsius of long-term warming there will be a near 10 percent increase in lightning activity. "During El Nino years, which occur in the Pacific Ocean or Basin, Southeast Asia gets warmer and drier. There are fewer thunderstorms, but we found fifty percent more lightning activity," says Prof. Price. Typically, he says,we would expect drier conditions to produce less lightning. However, researchers also found that while there were fewer thunderstorms, the ones that did occur were more intense. (link)

Here is an example from the recent bush fires in Australia. The yellow dots were lightning events from an incoming front that really brought no significant rain. The blue dots were active fires.

Even once the methane reacts with hydroxyls doesn't it then convert into CO2? Yes, it does. However, it needs to be mentioned that methane is measured in parts per billion (ppb) whereas carbon dioxide is measured in parts per million (ppm). So the resulting CO2 will be 1000 times less potent than the equivilant measurement of CO2 ppm.
Will the CO2 remain in the atmosphere for 100 years? Possibly, but once civilization has downsized there will be powerful sequestration forces.

From this article. Guy McPherson states

 Tickell is taking a conservative approach, considering humans have not been present at 3.5 C above baseline (i.e., the beginning of the Industrial Revolution, commonly accepted as 1750). 

That is not true. Lucy the earliest fossil record of hominid lived 3.2 million years ago (link). From this Scientific American article.

The last time the Earth enjoyed greenhouse gas levels like those of today was roughly 4 million years ago, during an era known as the Pliocene. The extra heat of average temperatures as much as 4 degrees Celsius warmer turned the tropical oceans into a nice warm pool of bathwater, as noted by new research published in Nature on April 4.

So the basic human body definitely functioned at 4 C warmer than we have today.
Again from the McPherson article

I’m not sure what it means to plan for 4 C (aka extinction) ... When there is no ability to grow food or secure water, humans will exit the planetary stage.

On what basis is this assumption of extinction made? That there would be no water or an ability to grow food anywhere? See the map in the conclusion for a world at 10 C higher than we are today.
Severely reduced in numbers? Yes. Extinction? No.

The article goes on to state

Earth’s atmosphere will harbor, at minimum, the current level of atmospheric carbon dioxide concentration for at least the next 1,000 years, as indicated in the 28 January 2009 issue of the Proceedings of the National Academy of Sciences.

This is not true, and not what the linked article states at all. From the link...

shows how changes in surface temperature, rainfall, and sea level are largely irreversible for more than 1,000 years after carbon dioxide (CO2) emissions are completely stopped.

McPherson is stating the CO2 levels will remain the same, which doesn't seem possible due to sequestration (more on this below). What the article is stating is that the effects will remain, not the CO2 concentration. The distinction is all important. If the CO2 concentration remained the warming effect would escalate. It won't post collapse. And this is a view that Mr. McPherson states

All of the above information fails to include the excellent work by Tim Garrett, which points out that only complete collapse avoids runaway greenhouse. 

From the same article;

In a provocative new study, a University of Utah scientist argues that rising carbon dioxide emissions – the major cause of global warming – cannot be stabilized unless the world’s economy collapses or society builds the equivalent of one new nuclear power plant each day.

I would agree the world's economy will collapse, but that does not equate to extinction. Once it does collapse the CO2 does not permanently remain in the atmosphere. 
Back to this article. Guy states

Writing on 28 November 2013 and tacking on only one feedback loop — methane release from the Arctic Ocean — Sam Carana expects global temperature anomalies up to 20 C 2050 (an anomaly is an aberration, or deviation from long-term average).

The really interesting part of that linked article is the statement;

As the Naval Research Laboratory animation below shows, sea ice in that area is rather thick. How it is possible for the methane to appear there? The answer must be, it seems, that there is so much movement in the sea ice in this area, that there are many cracks through which the methane can rise. 

We know from the hydrate analysis above, that it is not possible for the hydrates to melt at freezing temperatures, even above freezing if the depth is sufficient. Arctic News has stated that methane releases can come from earthquakes. Just 28 days before, there was a 5.3 earthquake (link). That would have given enough movement to release deep seated methane. The ice movement would have allowed that methane to escape into the atmosphere. As you can see in the image this is a volatile area

Continuing with the Arctic News article.

And while most efforts to contain global warming focus on ways to keep global temperature from rising with more than 2°C, a polynomial trendline already points at global temperature anomalies of 5°C by 2060. Even worse, a polynomial trend for the Arctic shows temperature anomalies of 4°C by 2020, 7°C by 2030 and 11°C by 2040, threatening to cause major feedbacks to kick in, including albedo changes and methane releases that will trigger runaway global warming that looks set to eventually catch up with accelerated warming in the Arctic and result in global temperature anomalies of 20°C+ by 2050.

This polynomial regression was generated with no negative feedbacks, all positive. It seems to have been taken as a given that this trend will be followed. However, it seems this trend line is already broken, from NASA;

The air temperatures across a broad swathe of the Arctic Ocean were 1-3°C lower than they were during 2007-2012 (Fig. 5). These relatively low temperatures are likely to have contributed to a notable increase in the minimum extent of the 2013 summer sea ice cover, relative to the record low in 2012.

The only way then for this polynomial to be accurately followed if it is redrawn with every new temperature. Of course, then it is not a projection of where values are going, simply a record of the existing state. The Guy McPherson essay uses this chart;

But this methane increase is from human activity, not from the Arctic. From this article.

The warming Arctic could add significant amounts of methane gas to the atmosphere as permafrost melts and releases huge quantities of gas trapped in previously frozen ground. While some studies indicate methane may already be escaping from the Arctic ground, atmospheric levels of methane in the Arctic have not increased yet, Dlugokencky said. Ed Dlugokencky, an atmospheric chemist with NOAA's Earth Sciences Research Laboratory in Boulder, Colo.

That article is dated 30 January 2014! So NOAA is stating the Arctic is not yet showing significant methane levels. But I agree, this is a "not yet" issue. Further in the McPherson article;

If you think we’ll adapt, think again.

He then goes on to state issues relating to evolution. However, evolution is not the same as adaptation. Humanity uses adaptation everyday, without having to evolve. We fly without having evolved wings. We adapted the technology to support our flight. Given the current population and emissions, collapse is inevitable. Survival post-collapse is what we need to adapt to. Guy then states;

On a positive note, major assessments fail to account for economic collapse. However, due to the four-decade lag between emissions and temperature rise, the inconvenient fact that the world has emitted more than twice the industrial carbon dioxide emissions since 1970 as we did from the start of the Industrial Revolution through 1970, and also due to the feedback loops described below, I strongly suspect it’s too late for economic collapse to extend the run of our species. 

I agree, I do not believe anything will change in the current economic system. History has demonstrated that the only way to dramatically change the system is through fundamental movements. That is complete boycotts, migration, revolutions or large scale death through disease. Our current system is so entrenched that gradual change will not occur fast enough to meet the threat.
Collapse is inevitable and we should be preparing for the subsequent 40 year period where the temperatures will spike. The temperatures that will result, will be survivable in some areas and in others, only with special preparation. In the McPherson article Guy states;

How long will the hangover persist, after we’re done with the fossil-fuel party? According to University of Chicago oceanographer David Archer: “The climatic impacts of releasing fossil fuel CO₂ to the atmosphere will last longer than Stonehenge,” Archer writes in his January 2008 bookThe Long Thaw. “Longer than time capsules, longer than nuclear waste, far longer than the age of human civilization so far.”

The article linked to gives this chart;

Notice though that the peak is at 1,400 ppm, it is unlikely that will those values will ever been seen. Here is what we have emitted so far ;

At roughly 10 ppm every 10 years, a collapse in 20 years would put us at 420ppm (let's say 500ppm). The dispersal mechanisms are different for Methane vs CO2. So we will just discuss CO2 here, so a collapse would put CO2 at somewhere in the mid 300s within 30-40 years after collapse. 

One of the forces for this process is sequestration into forests. While it is undeniable that forests are being cleared and certain species of trees attacked by pests, that is the current situation, not the one that will exist post-collapse. Some trees will thrive in a longer growing season. That will be balanced by fires, and here I am speaking from an Australian perspective. Our forests actually have evolved to need fire to reproduce, making Australia one of the most fire prone areas in the world.
We recently had massive fires within 1km of our house. The conclusion might be that the forest fires would release all the carbon dioxide back into the atmosphere, but that is not what actually happens with Australian native trees. They survive, albeit with a haircut, and new ones sprout. Some species actually require smoking to germinate. Any CO2 held in the trunk remains. More details here.

But this is not limited to Australian natives. Here is a list of fire retardant plants.
http://www.apsvic.org.au/plant_fire_resistant.html
http://www.wariapendi.com.au/hints-tips/fire-retardant-plants
So it is likely certain species will flourish as a carbon sink, and others will not be able to compete. What species will thrive will depend on the local climate specifics. Here is the Whittaker Biome diagram.

Given Methane though, those 30-40 years are going to be very hard times for mankind. In regards to methane many articles refer to the research (Light 2013) which states;

Furthermore over periods of a few months to a few years methane has a global warming potential from 1000 to 100 times that of carbon dioxide

2 points here a warming potential of 1000 is only realistic over a period of less than 5.7 months (Carana). In addition, that assumes the gas can disperse evenly across the globe, which is not possible in those timeframes. Therefore the warming potential is actually localized. The article goes on to state;

A giant pall of methane covers the Northern Hemisphere (Figures 9a,b)) and massive amounts methane have been erupting along the entire length of the Eurasian basin and the Laptev Sea from October to December, 2013 (Figures 10 - 12). The Eurasian basin was not a region of major emissions in 2012 (Figure 10, Extraction priority map) confirming that the rate of emission from destabilized Arctic subsea methane hydrates has increased at such a pace that the differences are now clearly discernable on atmospheric methane map data (Figures 10 and 11).

It makes the assumption that methane over the Eurasian basin was the result of melting hydrates. However, as shown previously this can only currently occur via earthquakes. Again from the Light article.

This confirms that the Gulf Stream (Atlantic) waters have got so hot that they are now destabilizing the methane hydrates throughout the entire Arctic Ocean and after they have made their exit from the Arctic Ocean as the East Greenland Current

There is a valid reason to suspect a destabilizing of the shallow sea bed (but more on that below), but certainly not the Eurasian basin, it would radically defy the physics of the hydrates. 
However, the Light article is then used as a platform for many other articles such as this one by Clinton Callahan which states;

Because of my research, my new collaboration partners at www.planetaryculture.com asked me to submit a blog paragraph about what the United Nations needs to know about methane and global warming for a paper they will read at the United Nations' Climate Summit set for 23 September 2014 in New York City....

According to Light's analysis, the temperature of Earth's atmosphere will resemble that of Venus before 2100....

Shakhova et al. in 2008 considered release of up to 50 Gt of predicted amount of hydrate storage as highly possible for abrupt release at any time.

However, Shakhova et al (2013) did not find or claim to have found a 50 Gt C reservoir of methane ready to erupt in a few years. That claim, which is the basis of the Whiteman et al (2013) $60 trillion Arctic methane bomb paper, remains as unsubstantiated as ever. - See more
So this and much of the work of Carana, Light and McPherson is based on 2008 Shakhova's work which has been realized as theoretical, not actually proven by observation. From the linked discussion;

I believed shallow methane hydrates were found disassociating at the ESAS because this is what has been stated repeatedly as if it is fact. Even with the caveats and qualifications, the existence of the hydrates has been stated again and again - I took this at face value and couldn't quite believe that it would be possible for scientists to make such statements with such seeming certainty and be wrong.

More recent research from Shakhova has shown the emission rate increasing. (link) So where is this methane coming from? From realClimate.org;

1. Decomposition (fermentation) of thawing organic carbon (see Azolla event)
2. Methane gas that has been trapped by ice
3. Decomposition (melting) of methane hydrates

There is a problem with (3), Methane hydrates can exist at the shallowness of the ESAS. But the problem is that there is simply insufficient pressure for them to form in the first place.

...methane hydrate can only form hundreds of meters below the sea floor in that setting, so thermodynamically, hydrate is not expected to be found at or near the sea floor. (Methane hydrate can be found close to the sediment surface in deeper water depth settings, as for example in the Gulf of Mexico or the Nankai trough). The implication is that it will take centuries or longer before heat diffusion through that sediment column can reach and destabilize methane hydrates. - (link) 

As this is the heart of the extinction alarm that article bears reading in full. The fear of an abrupt release at any time is unjustified according to Gavin Schmidt. Schmidt is a climate modeller at the NASA Goddard Institute

Assuming then that the sub sea permafrost methane is organic in nature then it should be noted that the region previously heated during the Early Holocene and then again in the Eemian to temperatures warmer than today. Would that imply that some of that organic methane would have previously emitted and has dissipated into the atmosphere? If so, how much is left? It doesn't seem possible that the source of the methane is abiotic, because of the depth profile of methane hydrates it would crystallize a long time before getting to the surface.

How much is venting now can be seen interactively here.

The problem is that a lot of assumptions regarding extinction have been made on theoretical values. The timing is not established, the volumes are unknown and assumptions are made on false premises in a chaotic climate with positive and negative feedbacks. The point of this has not been to disagree with the premise that the environment is about to dramatically change. In this environment, accurate predictions are impossible, all will not be established until it is well and truly happening. This needs to be considered in a background environment of dwindling energy reserves being sourced from increasingly volatile regions. 

All we can say with certainty is that there will be a period in human history possibly known as the collapse. (No point in saying Great it would be an understatement anyway). However perhaps because of the previous assumptions, statements have been made that equate collapse to extinction. These are not the same things. Only if you assume that there is no other civilization possible than the one we presently have, then humanity becomes extinct. But of course humans have had civilizations for thousands of years without anything close to our modern version. The issue is really whether or not we are prepared for the extreme environment we are about to face.

At this point I will say that Guy McPherson has made admiral attempts to get off the grid and be self-sufficient with his Mud Hut process. I admire his efforts, what I would suggest is that this approach be understood, but then extended, and that is what this site is about.

Conclusion

This is a great threat that is posed to humanity, but it must be approached rationally. Creating panic won't help. The point of this is not to say that it will not happen, the point is the speed at which it will occur and how long it will remain with us.

The Permo-Carboniferous had CH4 levels of 12,000 ppb at 20C. That is a lot different to our current levels of 1790 ppb. What this would imply is that should the methane hydrates rapidly emit methane that atmospheric concentrations will go up significantly. There is a potential that a depletion of hydroxyls in the atmosphere will allow the CH4 to remain in the atmosphere for longer. This will certainly decimate civilization in certain wide-spread areas. 

This and current CO2 levels would indicate a target climate as warm as, or warmer than that of the Mid-Pliocene. For arguments sake let's be pessimistic and target the Paleocene-Eocene Thermal Maximum (PETM). This is certainly not an event that will happen by 2036, as some are suggesting, but we will take it as being a target to determine whether it is survivable.

 it suggests a 6 °C (11 °F) rise from ~17 °C (63 °F) before the PETM to ~23 °C (73 °F) during the PETM. (link)

At the time there was limited ice at the poles, the poles and the equator experienced similar heating. The values suggested are average summer time night and day. We currently are at 12°C so that is looking at an 11°C increase. A radical change no doubt. Hottest temperature ever recorded was 56.7 °C in Death Valley. At 68°C you could be buttered.

Unfortunately we cannot look at geological history to determine what temperatures would be experienced in different locations because the land masses had moved since that time. The best tool we have is mathematical models and they predict the following wet bulb globe temperatures at 10°C.

Now during the PETM period there were extinctions. No doubt these extinctions are due to complex factors whereby older organism types were unable to compete with newer types and/or the loss of their food sources. However, this period also marks the beginning of primates on land, that's us.

2 things should be mentioned. The first is that there are areas that are survivable, above ground in summer. The second is that an average temperature of even 25C is survivable in cave structures like Coober Pedy, that is because shallow caves or mines acquire the average temperature of the surrounding soil. The surrounding soil acquires the average temperature of the atmosphere. There are many many complicating factors (water, food, security, community) that I am attempting to cover at this site.

 What is it exactly that is going to cause total extinction? 

A breakdown of society? No, as discussed elsewhere some areas will have Thorium reactors with a local supply.
Thermal events? Not for everyone, and not all the time
Oxygen depletion? Some parts yes, but not all by 2050
Oceanic death? No, but it will affect about 600 million people.
Anoxic oceans? Some parts definitely, but not all by 2050
Extreme weather? No, but it will result in migration
Food shortages? No, but it will result in migration
Nuclear pollution? Unlikely, even in the worst case scenarios the Southern hemisphere will probably be survivable.
Wars? Possibly, though Mutually Assured Destruction will limit the use of nuclear weapons. Also as discussed in the nuclear pollution post the effect will be much more pronounced in the Northern Hemisphere.

These effects are cumulative, and will result in a very hostile environment to live in, no doubt. Some people are predicting that as society disintegrates so will any chance of humanity surviving. If we are unprepared, then they may be right. But as the map above indicates not all the Earth will be uninhabitable. This is called extirpation (the death of populations) not extinction. That is why we should be planning, not panicking. The cumulative effects need to be dealt with very carefully, and that is what this site is about.

If you have any suggestions on anything I might be wrong about please comment. Particularly if it is of a technical nature.