Another link between CO2 and mass extinctions of species

By Andrew Glikson, Australian National University

Andrew Glikson, earth and
paleo-climate scientist at
Australian National University

It’s long been known that massive increases in emission of CO2 from volcanoes, associated with the opening of the Atlantic Ocean in the end-Triassic Period, set off a shift in state of the climate which caused global mass extinction of species, eliminating about 34% of genera. The extinction created ecological niches which allowed the rise of dinosaurs during the Triassic, about 250-200 million years ago.

New research released in Science Express has refined the dating of this wave of volcanism. It shows marine and land species disappear from the fossil record within 20,000 to 30,000 years from the time evidence for the eruption of large magma flows appears, approximately 201 million years ago. These volcanic eruptions increased atmospheric CO2 and increased ocean acidity.

Mass extinctions caused by rapidly escalating levels of CO2 have occurred before. Global warming image from www.shutterstock.com

Mass extinctions due to rapidly escalating levels of CO2 are recorded since as long as 580 million years ago. As our anthropogenic global emissions of CO2 are rising, at a rate for which no precedence is known from the geological record with the exception of asteroid impacts, another wave of extinctions is unfolding.

Mass extinctions of species in the history of Earth include:

• the ~580 million years-old (Ma) Acraman impact (South Australia) and Acrytarch (ancient palynomorphs) extinction and radiation 
• Late Devonian (~374 Ma) volcanism, peak global temperatures and mass extinctions 
• the end-Devonian impact cluster associated with mass extinction, which among others destroyed the Kimberley Fitzroy reefs (~360 Ma) 
• the upper Permian (~267 Ma) extinction associated with a warming trend
• the Permian-Triassic boundary volcanic and asteroid impact events (~ 251 Ma) and peak warming 
• the End-Triassic (201 Ma) opening of the Atlantic Ocean, and massive volcanism 
• an End-Jurassic (~145 Ma) impact cluster and opening of the Indian Ocean 
• the Cretaceous-Tertiary boundary (K-T) (~65 Ma) impact cluster, Deccan volcanic activity and mass extinction 
• the pre-Eocene-Oligocene boundary (~34 Ma) impact cluster and a cooling trend, followed by opening of the Drake Passage between Antarctica and South America, formation of the Antarctic ice sheet and minor extinction at ~34 Ma. 

Throughout the Phanerozoic (from 542 million years ago), major mass extinctions of species closely coincided with abrupt rises of atmospheric carbon dioxide and ocean acidity. These increases took place at rates to which many species could not adapt. These events – triggered by asteroid impacts, massive volcanic activity, eruption of methane, ocean anoxia and extreme rates of glaciation (see Figures 1 and 2) – have direct implications for the effects of the current rise of CO2.

Figure 1 – Trends in atmospheric CO2 and related glacial and interglacial periods since the Cambrian (542 million years ago), showing peaks in CO2 levels (green diamonds) associated with asteroid impacts and/or massive volcanism. CO2 data from Royer 2004 and 2006.

Figure 2 – Relations between CO2 rise rates and mean global temperature rise rates during warming periods, including the Paleocene-Eocene Thermal Maximum, early Oligocene, mid-Miocene, late Pliocene, Eemian (glacial termination), Dansgaard-Oeschger cycles, Medieval Warming Period, 1750-2012 and 1975-2012 periods.

In February 2013, CO2 levels had risen to near 396.80ppm at Mauna Loa Atmospheric Observatory, compared to 393.54ppm in February 2012. This rise – 3.26ppm per year – is at the highest rate yet recorded. Further measurements show CO2 is at near 400ppm of the atmosphere over the Arctic. At this rate the upper stability threshold of the Antarctic ice sheet, defined at about 500–600ppm CO2 would be reached later this century (although hysteresis of the ice sheets may slow down melting).

Our global carbon reserves – including coal, oil, oil shale, tar sands, gas and coal-seam gas – contain considerably more than 10,000 billion tonnes of carbon (see Figure 5). This amount of carbon, if released into the atmosphere, is capable of raising atmospheric CO2 levels to higher than 1000ppm. Such a rise in atmospheric radiative forcing will be similar to that of the Paleocene-Eocene boundary thermal maximum (PETM), which happened about 55 million years-ago (see Figures 1, 2 and 4). But the rate of rise surpasses those of this thermal maximum by about ten times.

Figure 3 – Plot of percent mass extinction of genera versus peak atmospheric CO2 levels at several stages of Earth history.

Figure 4 – The Paleocene-Eocene Thermal Maximum (PETM) represented by sediments in the Southern Ocean, central Pacific and South Atlantic oceans. The data indicate a) deposition of an organic matter-rich layer consequent on extinction of marine organisms; b) lowering of δ18O values representing an increase in temperature and c) a sharp decline in carbonate contents of sediments representing a decrease in pH and increase in acidity (Zachos et al 2008) 

The Paleocene-Eocene boundary thermal maximum event about 55 million years ago saw the release of approximately 2000 to 3000 billion tons of carbon to the atmosphere in the form of methane (CH4). It led to the extinction of about 35-50% of benthic foraminifera (see Figure 3 and 4), representing a major decline in the state of the marine ecosystem. The temperature rise and ocean acidity during this event are shown in Figures 4 and 6.

Based on the amount of carbon already emitted and which could continue to be released to the atmosphere (see Figure 5), current climate trends could be tracking toward conditions like those of the Paleocene-Eocene event. Many species may be unable to adapt to the extreme rate of current rise in greenhouse gases and temperatures. The rapid opening of the Arctic Sea ice, melting of Greenland and west Antarctic ice sheets, and rising spate of floods, heat waves, fires and other extreme weather events may signify a shift in state of the climate, crossing tipping points.

Figure 5 – CO2 emissions from fossil fuels (2.12 GtC ~ 1 ppm CO2). Estimated reserves and potentially recoverable resources.By analogy to medical science analysing blood count as diagnosis for cancer, climate science uses the greenhouse gas levels of the atmosphere, pH levels of the ocean, variations in solar insolation, aerosol concentrations, clouding states at different levels of the atmosphere, state of the continental ice sheets and sea ice, position of high pressure ridges and climate zones and many other parameters to determine trends in the climate. The results of these tests, conducted by thousands of peer-reviewed scientists world-wide, have to date been ignored, at the greatest peril to humanity and nature.

Continuing emissions contravene international laws regarding crimes against humanity and related International and Australian covenants. In the absence of an effective global mitigation effort, governments world-wide are now presiding over the demise of future generations and of nature, tracking toward one of the greatest mass extinction events nature has seen. It is time we learned from the history of planet Earth.

Figure 6: The Paleocene-Eocene boundary thermal maximum. http://www.uta.edu/faculty/awinguth/petm_research/petm_home.html

This article was earlier published at The Conversation (on March 22, 2013).

Earth is on the edge of runaway warming

The old picture, with Earth well within
our solar system's habitable zone

How well is Earth's orbit around the sun positioned within the boundaries of the habitable zone? The illustration by the Wikipedia image on the right would give that impression that Earth was comfortably positioned in the middle of this zone.

What is the habitable zone? To be habitable, a planet the size of Earth should be within certain distances from its Sun, in order for liquid water to exist on its surface, for which temperatures must be between freezing point (0° C) and boiling point (100° C) of water.

In the Wikipedia image, the dark green zone indicates that a planet the size of Earth could possess liquid water, which is essential since carbon compounds dissolved in water form the basis of all earthly life, so watery planets are good candidates to support similar carbon-based biochemistries.

If a planet is too far away from the star that heats it, water will freeze. The habitable zone can be extended (light green color) for larger terrestrial planets that could hold on to thicker atmospheres which could theoretically provide sufficient warming and pressure to maintain water at a greater distance from the parent star.

A planet closer to its star than the inner edge of the habitable zone will be too hot. Any water present will boil away or be lost into space entirely. Rising temperatures caused by greenhouse gases could lead to a moist greenhouse with similar results.

The distance between Earth and the Sun is one astronomical unit (1 AU). Mars is often said to have an average distance from the Sun of 1.52 AU. A recent study led by Ravi Kopparapu at Penn State mentions that early Mars was warm enough for liquid water to flow on its surface. However, the present-day solar flux at Mars distance is 0.43 times that of Earth. Therefore, the solar flux received by Mars at 3.8 Gyr was 0.75 × 0.43 = 0.32 times that of Earth. The corresponding outer habitable zone limit today, then, would be about 1.77 AU, i.e. just a bit too far away from the Sun to sustain water in liquid form. Venus, on the other hand, is too close to the Sun (see box below).

Kopparapu calculates that the Solar System’s habitable zone lies between 0.99 AU (92 million mi, 148 million km) and 1.70 AU (158 million mi, 254 million km) from the Sun. In other words, Earth is on the edge of runaway warming.

Image by Kopparapu et al. New calculations show that Earth is positioned on the edge of the habitable zone
(green-shaded region), boundaries of which are determined by the moist-greenhouse
(inner edge, higher flux values) and maximum greenhouse (outer edge, lower flux values)

Kopparapu says that if current IPCC temperature projections of a 4 degrees K (or Celsius) increase by the end of this century are correct, our descendants could start seeing the signatures of a moist greenhouse by 2100.

Kopparapu argues that once the atmosphere makes the transition to a moist greenhouse, the only option would be global geoengineering to reverse the process. In such a moist-greenhouse scenario, not only are the ozone layer and ice caps destroyed, but the oceans would begin evaporating into the atmosphere's upper stratosphere.

Venus' runaway greenhouse effect a warning for Earth by Sam Carana - first posted November 28, 2007, at: http://global-warming.gather.com/viewArticle.action?articleId=281474977189423 Venus was transformed from a haven for water to a fiery hell by an runaway greenhouse effect, concludes the European Space Agency (ESA), after studying data from the Venus Express, which has been orbiting Venus since April 2006. Venus today is a hellish place with surface temperatures of over 400°C (752°Fahrenheit), winds blowing at speeds of over 100 m/s (224 mph) and pressure a hundred times that on Earth, a pressure equivalent, on Earth, to being one km (0.62 miles) under the sea. Hakan Svedhem, ESA scientist and lead author of one of eight studies published on Wednesday in the British journal Nature, says that Earth and Venus have nearly the same mass, size and density, and have about the same amount of carbon dioxide. In the past, Venus was much more Earth-like and was partially covered with water, like oceans, the ESA scientists believe. How could a world so similar to Earth have turned into such a noxious and inhospitable place? The answer is planetary warming. At some point, atmospheric carbon triggered a runaway warming on Venus that boiled away the oceans. As water vapour is a greenhouse gas, this further trapped solar heat, causing the planet to heat up even more. So, more surface water evaporated, and eventually dissipated into space. It was a “positive feedback” -- a vicious circle of self-reinforcing warming which slowly dessicated the planet. “Eventually the oceans began to boil”, said David Grinspoon, a Venus Express interdisciplinary scientist from the Denver Museum of Nature and Science, Colorado, USA. “You wound up with what we call a runaway greenhouse effect”, Hakan Svedhem says. Venus Express found hydrogen and oxygen ions escaping in a two to one ratio, meaning that water vapor in the atmosphere the little that is left of what they believe were once oceans is still disappearing. While most of Earth's carbon store remained locked up in the soil, rocks and oceans, on Venus it went into the atmosphere, resulting in Venus' atmosphere now consisting of about 95% carbon dioxide. “Earth is moving along the curve that connects it to Venus”, warns Dmitry Titov, science coordinator of the Venus Express mission. References - Venus Express - European Space Agency (ESA) http://www.esa.int/SPECIALS/Venus_Express/SEMGK373R8F_0.html - Venus inferno due to 'runaway greenhouse effect', say scientists http://www.physorg.com/news115477239.html - Probe likens young Venus to Earth http://physicsworld.com/cws/article/news/32018 - European mission reports from Venus http://www.nature.com/nature/journal/v437/n7062/full/4371071a.html

References

- Habitable zones around main-sequence stars: new estimates

Ravi Kumar Kopparapu et al. 2013

http://iopscience.iop.org/0004-637X/765/2/131

- Habitable Zone - Wikipedia

http://en.wikipedia.org/wiki/Habitable_zone

- Earth is closer to the edge of Sun's habitable zone

http://physicsworld.com/cws/article/news/2013/mar/25/earth-is-closer-to-the-edge-of-suns-habitable-zone

- Updated model for identifying habitable zones around stars puts Earth on the edge

http://www.gizmag.com/habitable-zone/26051/

How much will temperatures rise?

Runaway Global Warming

If we take the NASA Annual Mean Land-Ocean Temperatures and draw a projection into the future, temperatures will quickly be 3 degrees Celsius higher than the base period (1951-1980), i.e. well before 2050, as illustrated on image 1. below. 

Image 1. Temperatures will be 3 degrees Celsius higher well before 2050

Above projection appears to be steeper than even the worst-case scenario pictured by the IPCC for years, such as on the image below.

Image 2. from IPCC 2001. Projections of globally averaged surface temperature 2000-2100 are shown for six SRES scenarios and IS92a using a model with average climate sensitivity. The grey region marked "several models all SRES envelope" shows the range of results from the full range of 35 SRES scenarios in addition to those from a range of models with different climate sensitivities. The temperature scale is departure from the 1990 value.

Could temperatures rise faster in future than what the IPCC anticipated in 2001? The answer must be yes! In 2007, the IPCC described that, even if greenhouse gas concentrations in the atmosphere were stabilized for 100 years at year 2000 values (B1), then we would still be committed to a further warming of 0.5°Celsius. This committed warming should not be confused with ‘unavoidable climate change’ over the next half century, which would be greater because forcing cannot be instantly stabilized. And of course, as it turned out, emissions have not been stabilized at 2000 values, but have in fact increased substantially.

As it turned out, the models used by the IPCC made all kinds of assumptions that didn't eventuate. But before deciding to instead settle for a relatively simple extrapolation of observed data, there are some issues that require a further look.  

As discussed in the earlier post Accelerated Arctic Warming, temperatures in the Arctic have been rising at a much faster pace than global temperatures, and if this accelerated rise continues, we can expect a 10 degrees Celsius rise in the Arctic before 2040, as illustrated by image 3. below.  

Image 3. Three kinds of warming - 2: Accelerated warming in the Arctic 

Such a temperature rise in the Arctic will undoubtedly lead to additional greenhouse gas emissions in the Arctic, of carbon dioxide, nitrous oxide and particularly methane, threatening to trigger runaway global warming. 

The image below, from the methane-hydrates blog, combines these three kinds of warming, showing global temperatures that soon catch up with accelerated Arctic warming, as heatwaves at high latitudes will cause wildfires, in particular in Siberia, where firestorms in peat-lands, tundras and forests could release huge amounts of emissions, including soot, much of which could settle on the Himalayan plateau, darkening the ice and snow and resulting in more local heat absorption. Rapid melt of glaciers will then cause flooding at first, followed by dramatic decreases in the flow of river water that up to a billion people now depend on for water supply and irrigation.

In other words, the situation looks much more dire than what most models make us believe; the more reason to adopt the climate plan that is also described at the post at the methane-hydrates blog.

Image 4. Three kinds of warming - 1, 2 and 3 

References

- IPCC (TAR) - Climate Change 2001: Synthesis Report

http://www.grida.no/publications/other/ipcc_tar/?src=/climate/ipcc_tar/vol4/english/figspm-10b.htm

- IPCC (AR4) - Climate Change 2007: Working Group I: The Physical Science Basis

http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch10s10-es-16-radiative-forcing.html#10-es-17-climate-change

- Accelerated Arctic Warming

http://arctic-news.blogspot.com/2013/01/accelerated-arctic-warming.html

- Methane hydrates

http://methane-hydrates.blogspot.com/2013/04/methane-hydrates.html

Advice for Parents at the End of the World

Douglas Spence -
Software Engineer and
concerned citizen

by Douglas Spence

The state of things today

We are in the early stages of an abrupt climate shift, driven initially by the disappearing Arctic albedo from sea ice and land snowpack. There are multiple other positive feedbacks set to come into play in the near future. We may have passed the point of no return where not even an immediate decision to deploy geoengineering could buy more time - and even if we did manage to buy more time - the prognosis for it being used to prevent the problem still looks very poor.

There is every chance that this will lead to the loss of global civilisation - widespread conflict and famine and general unpleasantness on a global scale. It is likely that this process will start in earnest sooner than it is comfortable to contemplate and be far worse than most people are capable of imagining. It is likely most people will perish.

While I think one should not entirely give up on averting catastrophe I think a realistic world view requires that one accept the possibility of failure and work on handling it. So what to do?

Simple Steps

The first thing to do is to stop being a passive observer. I encounter an increasing number of people who seem to intellectually grasp that we're in a very serious mess but who change nothing in their lives. Instead they either push it to the back of their mind as a tomorrow problem, or passively consume information on the internet or television and stare transfixed as the crash unfolds. So the first thing is to start - today, not tomorrow. Even today is really a bit late, but tomorrow is to declare your future not to be worth your effort.

The second thing is to arrive at a basic strategy. I can't tell you what form that will take as it depends a great deal upon your situation - where and how you currently live. I can say that there is plenty of straight-forward survivalist advice out there that will give you a good starting point. The hierarchy of needs - food, water, shelter - and so on. You need to determine how you will achieve those in a collapse scenario. Be careful to be realistic in determining how you will achieve them. If your plan is to travel into the mountains and hunt wildlife remember millions of other people will have the same idea. It may not be a realistic plan. The basics of surviving are a pre-requisite to anything else. In my opinion the ideal is to get into a remote region where the ratio of population to natural resource is favourable and where it is effectively inaccessible to most other people.

The third thing is to understand the limitations of the usual survivalist type information. Much depends upon the specifics of the situation you are preparing for. Climate change is unique in two ways that are unhelpful in terms of common survivalist thinking. Firstly it is a long duration problem (for many thousands of years at the very least) and a lot of the survivalist thinking equips you for a short duration problem. Secondly climate change means that the very environment we depend upon may change radically around us. That means that even if you already knew how to live off the land for your area right now (for example which plants are safe to eat) that is not necessarily going to give you a longer term strategy. Do remember that no matter how much food you store and how many tools you own - all these things are finite and will wear out. It is better to be excellent at problem solving than at hoarding tonnes of gear. It is also selfish to your children to predicate your existence upon short term answers, leaving them to solve more problems later. Sound familiar? That's because that's the sort of thinking that led to the climate crisis - and we must change it!

Accordingly once you are happy you have planned for the initial collapse episode, you need longer term plans. I suggest learning about the earth system and understanding what is likely to happen in the areas you are likely to be inhabiting. You also need to consider how your children and grandchildren will live into the indefinite future. I think you should think about the even longer term future:

Seven generation sustainability
http://en.wikipedia.org/wiki/Seven_generation_sustainability

Unfortunately it's easy to be lazy and short term. If our ancestors had cared about us seven generations ago - I am certain we wouldn't have these problems today. Accordingly, we must change this attitude if we value children. Those who do not will consign their descendents either to death or to the most primitive and brutal of existences.

Finally I strongly suggest you make sure you're on very good terms with your neighbours wherever you end up. The importance of community and social cohesion cannot be overstated. Make friends, not enemies.

A diverse range of seeds is essential - above examples scale up rapidly from low seed
numbers

On Children

It is beyond my comprehension at this point how anyone with children can NOT be preparing.

I would suggest that if you have children you start to help them become prepared - in ways that would make sense anyway. For example I believe children should know where food comes from. That means growing plants and raising and killing animals. They should also understand that if they value the ability to eat they should respect not only the world that provides those plants and animals but also the plant and animal itself. If one cannot respect something how can you look after it and in turn yourself?

I do not think you should lie to children, but on the other hand the truth should not be forced upon them either. Children usually have more flexible minds than adults and can arrive at their own understanding in their own time - if given as much truth as they reasonably ask for. We don't live in utopia and you can definitely be too protective. Particularly with younger children - make sure not to tell them things you don't want them to tell other people.

Make sure your children do not depend upon electronic gadgets and toys for emotional satisfaction. Help them to understand the simple beauty of nature and the real world. If they are old enough teach them the basic survival skills that count most. Perhaps the importance of clean water, how to make fire and how to respond to environmental stress in the form of dangerous heat and cold.

You and your children should be in good physical shape. That doesn't necessarily mean being a toned athlete but a basic standard of physical fitness is essential. A little stored body fat might actually be a good thing but certainly not enough to affect your fitness or mobility. A little of it could help you when you are starving. I would however note to all those who think an answer is to hoard lots of food - if you are obviously well fed while those around you starve, expect them to kill you and take your food. A modest stockpile is arguably a substantial advantage but only if used wisely.

It is essential to cultivate a practical and optimistic attitude. Instead of encouraging the all too common passive mindset of waiting for someone else to solve a problem (or of saying something is simply too hard) perseverance should be encouraged, and willingness to try. Ability to learn from failure is also important.

One of my pet peeves about how most people view the end of the world is they necessarily think the loss of civilisation and the descent of the world into violent conflict is a hopeless situation. They automatically think it will be dreadful and not worth trying to survive in. I can only say that I think the collapse itself will be a finite duration event (until the population is back within carrying capacity) and that the most important thing about being civilised is how people treat each other.

One can find happiness in small simple things if one is willing to accept it! Those things will never go away for those who value them.

What if you cannot survive?

Firstly, survival is mostly in the mind. In many cases your mental attitude is the biggest factor - not your physical limitations. A couple of examples:

• Juliane Koepcke
  http://en.wikipedia.org/wiki/Juliane_Koepcke
• For 40 Years, This Russian Family Was Cut Off From All Human Contact, Unaware of WWII
  http://www.smithsonianmag.com/history-archaeology/For-40-Years-This-Russian-Family-Was-Cut-Off-From-Human-Contact-Unaware-of-World-War-II-188843001.html

Secondly, if you genuinely think yourself unable to survive in a collapsed world, I can only suggest the following:

1. Do your absolute best to try to stop things from collapsing - this is by definition your best survival strategy 
2. Help someone else - if your good deeds can live longer than you, why not try to help future generations? 

Good luck.