Sunday, May 4, 2014

Will the Anthropocene last for only 100 years?

On November 9, 2013, methane levels as high as 2662 ppb (parts per billion) were recorded, as indicated by the red dot on the image below.

This image, from an earlier post, gives an idea of the height of this level compared to historic methane levels, and how fast levels of methane (CH4) have been rising compared to levels of two other greenhouse gases, i.e. carbon dioxide (CO2) and nitrous oxide (N2O).

CO2 concentrations in the atmosphere have now risen to levels well above the 400 parts per million (ppm), as illustrated by the graph below, from This 400 ppm is 143% the pre-industrial peak level of 280 ppm.

Paleorecords show that greenhouse gases levels go up and down in lockstep with temperatures in history. The image below shows that carbon dioxide levels back in history typically moved between approximately 180 ppm and 280 ppm, a difference of 100 ppm. Since 1950, CO2 levels have risen by roughly the same difference.

In a fascinating lecture, Dr Jan Zalasiewicz suggests that the Anthropocene started around 1950, when levels of greenhouse gases started to rise exponentially, in line with the rise of fossil fuel use, as also illustrated by the image below.

The image below, from an earlier post, shows that temperatures typically moved up and down by roughly 10 degrees Celsius between a glacial and interglacial phase of the ice ages, suggesting that a 100 ppm rise of carbon dioxide and 300 ppb rise of methane go hand in hand with a 10°C temperature rise.

Many eminent scientists have warned that the high current carbon dioxide levels have already locked us in for a future temperature rise of several degrees Celsius, a rise that is yet to fully manifest itself and that is only held off by the temporary masking effect of sulfur dioxide that is emitted when burning fuel (especially coal) and by the (decreasing) capacity of oceans, ice sheets and glaciers to act as a buffer for heat. Once the masking effect of sulfur dioxide ends and the Arctic sea ice collapses, a huge sudden rise in temperature can be expected, hitting vulnerable pools (see image below) which would accelerate the temperature rise even more and could cause temperatures to rise by another 10°C within decades.

The scenario of such a huge rise in temperature becomes a distinct possibility when considering the combined warming impact of carbon dioxide, methane, nitrous oxide, water vapor and albedo changes, and the vulnerability of some of the terrestrial and marine carbon pools. Also note that, while the above Unesco image gives an estimate of 104 or 10,000 Gt C for ocean methane hydrates, several studies give even higher estimates, as illustrated by the image below, from Pinero et al.

The amount of carbon stored in hydrates globally was in 1992 estimated to be 10,000 Gt (USGS), while a later source gives a figure of 63,400 Gt C for the Klauda & Sandler (2005) estimate of marine hydrates. A warming Gulf Stream is causing methane eruptions off the North American coast. Furthermore, methane appears to be erupting from hydrates on Antarctica, on the Qinghai-Tibetan Plateau and on Greenland. In just one part of the Arctic Ocean alone, the East Siberian Arctic Shelf (ESAS), up to 1700 Gt of methane is contained in sediments in the form of methane hydrates and free gas. A sudden release of just 3% of this amount could add over 50 Gt of methane to the atmosphere, i.e. some seven times what is in the atmosphere now, and experts consider such an amount to be ready for release at any time.

Importantly, methane levels have risen even more strongly than carbon dioxide levels. As the image at the top of this post shows, the current methane level is 250% its pre-industrial peak level, i.e. 1100 ppb above the pre-industrial peak level of 700 ppb. Historically, methane has only moved by some 300 ppb between a glacial and interglacial phase of the ice ages. IPCC/NOAA figures suggest that global mean methane levels have been rising by 5 or 6 ppb annually over recent years and there are some worrying indications that the rise of methane levels might accelerate even further.

To obtain mean methane abundance, measurements are typically taken at an altitude of 586 mb, as methane typically shows up most prominently at this altitude. Indeed, mean methane levels were highest at this altitude in April 2013, at just under 1800 ppb. Looking at mean global methane levels in April 2014 at this altitude, one could at first glance conclude that the situation had not changed much, and that 2014 methane levels had merely risen by a few ppb, in line with IPCC data. So, at first glance one might conclude that there may appear to be only a minimal rise (if any at all) in global mean methane levels when taking measurements at lower altitudes.

The image below illustrates this. What should be added is that the analysis used only selected altitudes and only used part of all data. So, further analysis may be necessary to verify these findings.

Importantly, closer examination of above graph shows that the situation is dramatically different when looking at the rise in methane levels at higher altitudes. A huge rise in mean methane levels appears to have taken place, to the extent that the highest mean level is now reached at 469 mb. Overall, the average rise in methane across the altitudes that are highlighted in the image is no less than 16 ppb.

The table below shows the altitude equivalents in mb (millibar) and feet.
56925 feet44689 feet36850 feet30569 feet25543 feet19819 feet14383 feet8367 feet1916 feet
74 mb147 mb218 mb293 mb367 mb469 mb586 mb742 mb945 mb

As the image below illustrates, this rise appears to go hand in hand with much higher peak readings, especially at higher altitudes. It appears that the additional methane originates from the higher latitudes of the Northern Hemisphere and has over the past few months moved closer to the equator, which is what typically occurs as methane rises in altitude.

Peak readings in above image are averages over April. On specific days, peak readings could be much higher, e.g. on April 28, 2014, methane levels were recorded as high as 2551 ppb at 469 mb.

As said, there appears to be a 16 ppb rise when comparing global mean methane levels between April 2013 and April 2014. Indeed, the culprit appears to be the rapid rise of methane emissions from hydrates that has been documented by this blog and that I estimated to amount to 99 Tg annually, as illustrated by the image below, from an earlier post.

So, it appears that the rise of methane in the atmosphere is accelerating. What can we expect? As temperatures can be expected to continue to rise and as feedbacks start to kick in, this may well constitute a non-linear trend. The image below shows a polynomial trend that is contained in IPCC AR5 data from 1955 to 2011, so they didn't include this recent steep rise. Nonetheless, the polynomial trendline points at methane reaching mean global levels higher than 3000 ppb by the year 2030. If methane starts to erupt in large quantities from clathrates underneath the seafloor of the Arctic Ocean, this may well be where we are heading.
So, how high could temperatures rise? Worryingly, a non-linear trend is also contained in the temperature data that NASA has gathered over the years, as described in an earlier post. A polynomial trendline 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.

Without action, it appears that the Antropocene will lead to extinction of the very human beings after which the era is named, with the Anthropocene only running from 1950 to 2050, a mere 100 years and much too short to constitute an era. In that case a better name would be the Sixth Extiction Event, as also illustrated by the image below, from an earlier post.

In conclusion, it's high time that we start acting as genuinely wise modern human beings and commit to comprehensive and effective action as discussed at the Climate Plan blog.


  1. If we look at the point in time when large-scale use of phosphate rather than bat guano or other manure fertilizers began, world population stood at about two billion people. That point in time was during the 1920s into the 1930s. The Great Depression and World War II then limited population growth, even though from the late 1930s on the use of fossil fuels exploded in the run-up to war.

    Once the war ended rapid population growth ensued, made possible by fossil fuels and phosphate, as well as by numerous advances in medicine and medical care, with a lot of the advances in medical care coming during WWII and the Korean War.

    When did the Anthropocene era start? I would say that the large-scale switch from various kinds of manure to phosphate chemical fertilizer as well as the switch from coal to oil-based fuels as the largest source of power and heat generation, combined with the vast rapid advance in medical care and in prescription drugs along with vitamins and food nutrient additives, marks the approximate beginning of the Anthropocene era.

    Here is some interesting comment from Jeremy Grantham and Business Insider on the subject of a looking eventual exhaustion of world phosphate supply along with an eventual population crash because of it, along with world population growth and phosphate use charts:

  2. You have a wonderful blog !
    Most people will get your smart analyses only when it will be too late to fight against it ...

    1. My gut tells me it's already too late. We're facing the effects of CO2 released up until 1974. With a 40 year lag between emissions and their ability to effect warming, I'm expecting the hardest hits are yet to come. To get an idea of what we're in for, dig this: a recent study indicated that in the last 29 years as much CO2 was belched into the atmosphere as during all the previous years of the Industrial Revolution prior to 1974!

    2. I forgot to include the fact that, along with all the carbon dioxide reaching altitude, the methane bomb will be joining the party.

      Am I correct in saying that methane is effective as a GHG at low altitudes? I read somewhere that it is. If so, my gut feelings are going to overload!

    3. For more on methane's warming potential see also FAQ #13 and methane hydrates

    4. Wow! That's an amazing wealth of information. Thank you for your good work.

  3. Which percentage of the current emission of methane is attributable to FRACKING ? I have been told a good 7%.

    1. There are several major issues involved in fracking and methane emissions. Several recent studies have estimated a 6-7% rate of well casing and/or well casing cementing failure over some period of years, which contaminates groundwater and eventually releases airborne contaminates, including methane; several recent major university studies have found a 3-7% well and natural gas transmission system leakage rate between the well and the end user, mainly due to deteriorating underground piping and compressor leaks, and several recent major university studies have found very high rates of airborne methane leakage from drilling (fracking) operations, that exceed the US Federal standard by as much as 1000 times.

      So in answer to your question, if we combine the known studied fracking leakage rates, well-casing and/or well-cementing leakage rates, and natural gas transmission system leakage rates, and then also add known drilling rig explosions where natural gas has been leaked, along with the occasional explosion elsewhere in the distribution system, the total natural gas industry methane leakage is well above 7% of total natural gas extracted, which makes natural gas even worse in climate change impact than burning soft lignite coal or even petcoke refinery tailings would be.

      It should be noted that the climate change impact of the natural gas industry leakage rate is also exacerbated by the industry-wide practice of flaring excess gas, as well as due to the 1200-1500 tractor-trailer truckloads necessary to drill a single frack well, along with the paved road damage that the trucks cause, which must then be repaired causing even more carbon emissions too.

      This is a good piece on fracking impacts from Western Resource Advocates in Boulder, CO:

  4. I think they should back date the Anthropocene and the Sixth Great Extinction to around 2m years ago when we began to drive the megafauna to extinction. Then, wouldn't we qualify as an era???

    1. There is unlimited potential to peacefully prosper if we can maybe break with bad habits. Knock on wood.
      Key is correcting root core monetary accounting error that allows the externalization of value- importance of Earth. Making this Law and enforcing it in a rapid change ending Money as we know it so it no longer can be slush fund agent isolating value of health of Earth's ecosystems that hold HZ through thick and thin naturally. But heat pulse hitting methane Clathrate stability zone and ocean flow changes and a whole host of feedbacks are going to continue to try to accelerate to extinct us.. This is a great challenge or test.
      Basically what we have here is an in process extinction event which we as agent could redirect our force. Redirect it so what we do to make living helps restore Open Systems.
      I expressed this in comment to Dr Light's article about Gulf Stream here at Arctic News -explained about system isolation and how present monetary is and how entropy is forced to rise by Physical Law.
      Basically, when monetary security is propped up by construct lacking accountability, like present corporate world is, it's flat lethal to Earth. We can change that and are in process change on whole so simply put, civilization lines up with Earth alive. Let's remove evil from money so as to clear the way to possibly succeed. And so ingenuity of youth will zoom like the Universe has never seen.. Up Up Up.

  5. Wish there was good news related to methane hydrate destabilization, but they are destabilizing even at lower latitudes than the Arctic:

    1. Yes, that's the Carolina Rise off the North American coast. I have meanwhile added more places where hydrates are venting, such as that one, which was also discussed in an earlier post.

  6. Anthropocene fueled by industrial fixing of nitrogen. Hober-Bosh Process is blame. All American crops have been engineered to eat and sequester methane from ambient air. The crops for one season cycles the entirety of methane emissions. 700 Tg

  7. PIOMAS -it looks bad:

  8. The Anthropocene could last for only 65 years, not because civilization will end in 2015, but because that could be the year when humanity will start to fundamentally accept the need to clean up the environment. Accordingly, this could be the start of the Ecocene.