How many deaths could result from failure to act on climate change?

A recent OECD study concludes that outdoor air pollution is killing more than 3.5 million people a year globally. The OECD estimates that people in its 34 Member countries would be willing to pay USD 1.7 trillion to avoid deaths caused by air pollution. Road transport is likely responsible for about half.

A 2012 report by DARA calculated that 5 million people were dying each year from climate change and carbon economies, mostly from indoor smoke and (outdoor) air pollution.

Back in 2012, a Reuters report calculated that this could add up to a total number of 100 million deaths over the coming two decades. This suggests, however, that failure to act on climate change will not cause even more deaths due to other causes.

Indeed, failure to act on climate change could result in many more deaths due to other causes, in particular food shortages. As temperatures rise, ever more extreme weather events can be expected, such as flooding, heatwaves, wildfires, droughts, and subsequent crop loss, famine, disease, heat-stroke, etc.

So, while currently most deaths are caused by indoor smoke and outdoor air pollution, in case of a failure to act on climate change the number of deaths can be expected to rise most rapidly among people hit by famine, fresh water shortages, as well as wars over food, water, etc.

How high could figures rise? Below is an update of an image from the earlier post Arctic Methane Impact with a scale in both Celsius and Fahrenheit added on the right, illustrating the danger that temperature will rise to intolerable levels if little or no action is taken on climate change. The inset shows projected global number of annual climate-related deaths for these two scenarios, i.e. no action and little action, and also shows a third scenario of comprehensive and effective action that would instead bring temperature rise under control.

[ click on image to enlarge ]

For further details on a comprehensive and effective climate plan, see the ClimatePlan blog.

Post by Sam Carana.

Large Falls in Arctic Sea Ice Thickness over May 2014

Comparing ice thickness (in meters) on May 2, 2014 (left) and May 30, 2014 (right, forecast run May 25, 2014)

Arctic sea ice has shown large falls in thickness in many areas over the course of May 2014, as shown on above image. The animation below also compares the situation between May 2, 2014, and May 30, 2014 (as forecast by Naval Research Laboratory on May 23, 2014). Ice thickness is in meters.

Thickness is an important indicator of the vulnerability of the ice. If only looking at sea ice extent, one might (wrongly) conclude that sea ice retreat was only minor and that everything looked fine. By contrast, when looking at thickness, it becomes evident that large falls have occurred over the course of May 2014.

Falls at the edges of the sea ice can be expected at this time of the year, but the large fall closer to the center is frightening. On the one hand, it appears to reflect cyclonic weather and subsequent drift of the ice. On the other hand, it also indicates how vulnerable the sea ice has become. Last year, a large area showed up at the center of the sea ice where the ice became very thin, as discussed in July 2013 in the post Open Water at North Pole and again in the September 2013 post North Hole.

The appearance of huge weak areas at the center of the sea ice adds to its vulnerability and increases the prospect of total sea ice collapse, in case of one or more large cyclones hitting the Arctic Ocean later this year. To highlight the dangerous situation, the main image from a post earlier this month is again added below.

Adding to the concerns are huge sea surface temperature anomalies, as illustrated by the image below, showing anomalies at May 23, 2014, and created by Harold Hensel with ClimateReanalyzer and Google Earth.

[ click on image to enlarge ]

The image below shows sea surface anomalies on May 26, 2014, with an overlay of land temperatures, as created by Harold Hensel and edited by Sam Carana.

The image shows sea surface temperatures on the Northern Hemisphere that are 1.44 degrees Celsius warmer than the baselline temperature, despite large areas with cold water partly resulting from the huge amounts of meltwater flowing down along the edges of Greenland into the North Atlantic Ocean. The graph below shows Northern Hemisphere and Global sea surface temperature anomalies over May 2014.

By comparison, current (May 27, 2014) surface temperature anomalies of 0.64°C globally and 0.84°C for the NH. The image below shows annual temperature anomalies (land and ocean data).

Meanwhile, the development of this year's 'north hole' at the center of the sea ice appears to persist, as illustrated by the image below.

Post by Sam Carana.

The real budgetary emergency and the myth of "burnable carbon"

by David Spratt

How fast and how profoundly we act to stop climate change caused by human actions, and work to return to a safe climate, is perhaps the greatest challenge our species has ever faced, but are we facing up to what really needs to be done?

We have to come to terms with two key facts: practically speaking, there is no longer a "carbon budget" for burning fossil fuels while still achieving a two-degree Celsius (2°C) future; and the 2°C cap is now known to be dangerously too high.

No Carbon Budget Left - David Spratt from Breakthrough  -  "We have no carbon budget left
for burning of fossils fuels - emergency action is now the only viable path"  - David Spratt

For the last two decades, climate policy-making has focused on 2°C of global warming impacts as being manageable, and a target achievable by binding international treaties and incremental, non-disruptive, adjustments to economic incentives and regulations (1).

But former UK government advisor Professor Sir Robert Watson says the idea of a 2°C target "is largely out of the window”, International Energy Agency chief economist Fatih Birol calls it "a nice Utopia", and international negotiations chief Christiana Figueres says we need "a miracle". This is because, in their opinions, emissions will not be reduced sufficiently to keep to the necessary "carbon budget" (2).

The carbon budget has come to public prominence in recent years, including in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report in 2013, as being the difference between the total allowable greenhouse gas emissions for 2°C of warming, and the amount already emitted or spent. The budget varies according to the likelihood of overshooting the target: the higher the risk, the bigger the budget. In the IPCC report, no carbon budget is given for less than a one-in-three chance of failure.

At that one-in-three risk of failure, the IPCC says the total budget is 790 GtC (gigatons, or one billion tons, of carbon), less emissions to 2011 of 515 GtC, leaving a budget of 275 GtC in 2011, or ~245 GtC in 2014 (3).

What is less well understood is that if the risk is low, there is no carbon budget left (4).

Breakthrough National  Climate Restoration
Forum 21-22 June,  Melbourne

Climate change with its non-linear events, tipping points and irreversible events – such as mass extinctions, destruction of ecosystems, the loss of large ice sheets and the triggering of large-scale releases of greenhouse gases from carbon stores such as permafrost and methane clathrates – contains many possibilities for catastrophic failure.

Ian Dunlop, a former senior risk manager and oil and coal industry executive, says the management of catastrophic risk has to be very different from current processes. As serious, irreversible outcomes are likely, this demands very low probabilities of failure: management of catastrophic risk "must centre around contingency planning for high-impact and what were regarded as low-probability events, which unfortunately are now becoming more probable… Major, high-risk industrial operations, such as offshore oil exploration, provide a model, with detailed contingency planning and sequential barriers being put in place to prevent worst-case outcomes" (5).

If a risk-averse (pro-safety) approach is applied – say, of less than 10% probability of exceeding the 2°C target – to carbon budgeting, there is simply no budget available, because it has already been used up. A study from The Centre for Australian Weather and Climate Research shows that "the combination of a 2°C warming target with high probability of success is now unreachable" using the current suite of policy measures, because the budget has expired (6).

This is illustrated in Figure 1 where, as we move to the right (greater probability of meeting target) along the blue line which is the 2°C carbon budget, we reach a point around 90% probability (blue circle) where the total budget intersects with what we have already emitted.

As well, on-going greenhouse emissions associated with food production and deforestation are often conveniently pushed to one side in discussing carbon budgets. UK scientists have shown that if some reasonably optimistic assumptions are made about deforestation and food-related emissions for the rest of the century, then most emission reduction scenarios are incompatible with holding warming to +2ºC, even with a high 50% probability of exceeding the target. In other words, food and deforestation has taken up the remaining budget, leaving no space for fossil fuel emissions (7).

In addition, the carbon budget analysis makes optimistic and risky assumptions about the stability of Arctic, and of polar and other carbon stores such as permafrost. As one example, the modelling discussed in the IPCC report projects an area of summer Arctic sea-ice cover in the year 2100 higher that actually exists at the moment, yet there is a great deal more warming and sea-ice loss to come this century! In fact, many Arctic specialists think the Arctic will be sea-ice free in summer within the next decade, with consequences for global warming that the carbon budget calculations have significantly underestimated. (8)

Australian Climate Council member Prof. Will Steffen says the IPCC carbon budget may "be rather generous". The IPCC report says the modelling used does not include explicit representation of permafrost soil carbon decomposition in response to future warming, and does not consider slow feedbacks associated associated with vegetation changes and ice sheets. Recent research suggests these events could happen well below 2°C of warming, so they should be taken into account, but they are not.

Accounting for the possible release of methane from melting permafrost and ocean sediment implies a substantially lower budget (9). This reinforces the need to take a pro-safety, risk-averse approach to the carbon budget, especially since some research suggests that Arctic permafrost may be vulnerable at less than 2°C or warming (10).

For all these reasons – that is, prudent catastrophic risk management, accounting for food production and deforestation emissions, and for Arctic sea ice and carbon store instability – the idea of "burnable carbon" – that is, how much more coal, gas and oil we can burn and still keep under 2°C – is a dangerous illusion, based on unrealistic, high-risk, assumptions.

A second consideration is that 2°C of warming is not a safe target. Instead, it's the boundary between dangerous and very dangerous (11), and 1°C higher than experienced during the whole period of human civilisation (12), illustrated in Figure 2. The last time greenhouse gas levels were as high as they are today, modern humans did not exist (13), so we are conducting an experiment for which we have no direct observable evidence from our own history, and for which we do not know the full result.

However, we do understand that many major ecosystems will be lost, a 2°C sea-level rise will eventually be measured in the tens of metres (14), and much of human civilisation and large, productive river delta systems will be swamped. There is now evidence to suggest that the current conditions affecting the West Antarctic ice sheet are sufficient to drive between 1.2 and 4 metres of sea rise (15), and evidence that Greenland will contribute more quickly (16), and they are just two contributors to rising sea levels.

It is now clear that the incremental-adjustment 2°C strategy has run out of time, if for no other reason than the "budget" for burning more fossil fuels is now zero, yet the global economy is still deeply committed to their continuing widespread use.



We all wish the incremental-adjustment 2°C strategy had worked, but it hasn't. It has now expired as a practical plan.

We now have a choice to make: accept much higher levels of warming of 3–5°C that will destroy most species, most people and most of the world's ecosystems; a set of impacts some more forthright scientists say are incompatible with the maintenance of human civilisation.

Or we can conceive of a safe-climate emergency-action approach which would aim to reduce global warming back to the range of conditions experienced during the last 10,000 years, the period of human civilisation and fixed settlement. This would involve fast and large emissions reduction through radical energy demand reductions, whilst a vast scaling-up of clean energy production was organised, together with the remaking of many of our essential systems such as transport and food production, with the target being zero net emissions. In addition, there would need to be a major commitment to atmospheric carbon dioxide drawdown measures. This would need to be done at a speed and scale more akin to the "war economy", where social and economic priority is given to what is perceived to be an overwhelming existential threat.

After 30 years of climate policy and action failure, we are in deep trouble and now have to throw everything we can muster at the climate challenge. This will be demanding and disruptive, because there are no longer any non-radical, incremental paths available.

Prof. Kevin Anderson and Dr Alice Bows, writing in the journal Nature, say that "any contextual interpretation of the science demonstrates that the threshold of 2°C is no longer viable, at least within orthodox political and economic constraints" and that "catastrophic and ongoing failure of market economics and the laissez-faire rhetoric accompanying it (unfettered choice, deregulation and so on) could provide an opportunity to think differently about climate change" (17).

Anderson says there is no longer a non-radical option, and for developed economies to play an equitable role in holding warming to 2°C (with 66% probability), emissions compared to 1990 levels would require at least a 40% reduction by 2018, 70% reduction by 2024, and 90% by 2030. This would require "in effect a Marshall plan for energy supply". As well low-carbon supply technologies cannot deliver the necessary rate of emission reductions and they need to be complemented with rapid, deep and early reductions in energy consumption, what he calls a radical emission reduction strategy (18). All this suggests that even holding warming to a too-high 2°C limit now requires an emergency approach.

Emergency action has proven fair and necessary for great social and economic challenges we have faced before. Call it the great disruption, the war economy, emergency mode, or what you like; the story is still the same, and it is now the only remaining viable path.

keynote speaker, David Spratt, explains why there is no carbon budget left to burn.

Sources:
This article was originally published at ClimateCodeRed.org
Above video, NO CARBON BUDGET LEFT TO BURN, was uploaded by Breakthrough.



Notes

1. Jaeger, C.C. and J. Jaeger (2011), "Three views of two degrees", Reg. Environ. Change, 11: S15-S26; Anderson, K. and A. Bows (2012) “A new paradigm for climate change”, Nature Climate Change 2: 639-70
2. http://www.bbc.co.uk/news/science-environment-19348194; http://www.guardian.co.uk/environment/2011/may/29/carbon-emissions-nuclearpow; http://www.smh.com.au/environment/weather/climate-pioneers-see-little-chance-of-avoiding-dangerous-global-warming-20131105-2wyon.html
3. IPCC (2013) "Working Group I Contribution to the IPCC Fifth Assessment Report Climate Change 2013; The Physical Science Basis: Summary for Policymakers"
4. "For a 90% probability of not exceeding 2C of warming the carbon budget had reduced to zero by 2012, using a multi-agent (that is, the well-mixed greenhouse gases, including CO2 and CH4)", Raupach (2013, unpublished), based on Raupach, M. R., I.N. Harman and J.G. Canadell (2011) "Global climate goals for temperature, concentrations, emissions and cumulative emissions", Report for the Department of Climate Change and Energy Efficiency. CAWCR Technical Report no. 42. Centre for Australian Weather and Climate Research, Melbourne; Rogelj, J., W. Hare et al. (2011) "Emission pathways consistent with a 2°C global temperature limit", Nature Climate Change 1: 413-418 show at Table 1 no feasible pathways for limiting warming to 2°C during the twenty-first century with a "very likely" (>90%) chance of staying below the target, without carbon drawdown.
5. Dunlop, I. (2011), "Managing catastrophic risk", Centre for Policy Development, 
http://cpd.org.au/2011/07/ian-dunlop-managing-catastrophic-risk/
6. Raupach, M. R., I.N. Harman and J.G. Canadell (2011) "Global climate goals for temperature, concentrations, emissions and cumulative emissions", Report for the Department of Climate Change and Energy Efficiency. CAWCR Technical Report no. 42. Centre for Australian Weather and Climate Research, Melbourne. 
7. Anderson, K. and A. Bows (2008) “Reframing the climate change challenge in light of post-2000 emission trends”, Phil. Trans. R. Soc. A 366: 3863-3882; Anderson, K. and A. Bows (2011) “Beyond ‘dangerous’ climate change: emission scenarios for a new world”, Phil. Trans. R. Soc. A 369: 20–44
8. Wadhams, P. (2012) “Arctic ice cover, ice thickness and tipping points”, AMBIO 41: 23–33; Maslowski, W., C.J. Kinney et al. (2012) "The Future of Arctic Sea Ice", The Annual Review of Earth and Planetary Sciences, 40: 625-654
9. IPCC (2013) "Working Group I Contribution to the IPCC Fifth Assessment Report Climate Change 2013; The Physical Science Basis;
10. Vaks, A., O.S. Gutareva et al. (2013) “Speleothems Reveal 500,000-Year History of Siberian Permafrost”, Science 340: 183-186; Schaefer, K., T. Zhang et al. (2011) "Amount and timing of permafrost carbon release in response to climate warming", Tellus 63:165-180
11. Anderson, K. and A. Bows (2011) “Beyond ‘dangerous’ climate change: emission scenarios for a new world”, Phil. Trans. R. Soc. A 369: 20–44
12. Marcott, S.A, J.D. Shakun et al. (2013) "A Reconstruction of Regional and Global Temperature for the Past 11,300 Years", Science 339: 1198-120; Hansen, J., P. Kharecha et al. (2013) "Assessing 'dangerous climate change': Required reduction of carbon emissions to protect young people, future generations and nature", Plos One 8: 1-26
13. Tripadi, A.K., C.D. Roberts et al. (2009), "Coupling of CO2 and Ice Sheet Stability Over Major Climate Transitions of the Last 20 Million Years", Science 326: 1394-1397
14. Rohling, E. J.,K. Grant et al. (2009) “Antarctic temperature and global sea level closely coupled over the past five glacial cycles”, Nature GeoScience, 21 June 2009 `af
15. NASA (2014), "NASA-UCI Study Indicates Loss of West Antarctic Glaciers Appears Unstoppable", Media release, 12 May 2014, http://www.nasa.gov/press/2014/may/nasa-uci-study-indicates-loss-of-west-antarctic-glaciers-appears-unstoppable, accessed 19 May 2014; Rignot, E., J. Mouginot et al. (2014) "Widespread, rapid grounding line retreat of Pine Island, Thwaites, Smith and Kohler glaciers, West Antarctica from 1992 to 2011", Geophysical Research Letters, doi: 10.1002/2014GL060140; Joughin, I., B.E. Smith et al. (2014), "Marine Ice Sheet Collapse Potentially Under Way for the Thwaites Glacier Basin, West Antarctica", Science 344: 735 -738
16. NASA (2014), "Hidden Greenland Canyons Mean More Sea Level Rise", Media release, 19 May 2014, http://www.nasa.gov/press/2014/may/hidden-greenland-canyons-mean-more-sea-level-rise, accessed 19 May 2014; Morlighem, M., E. Rignot et al. (2014), "Deeply incised submarine glacial valleys beneath the Greenland ice sheet", Nature Geoscience, doi:10.1038/ngeo2167
17. Anderson, K. and A. Bows (2012) “A new paradigm for climate change”, Nature Climate Change 2: 639-70
18. Anderson, K. (2014) "Why carbon prices can’t deliver the 2°C target", 13 August 2013, http://kevinanderson.info/blog/why-carbon-prices-cant-deliver-the-2c-target, accessed 19 May 2014; Anderson, K. (2012) "Climate change going beyond dangerous – Brutal numbers and tenuous hope", Development Dialogue, September 2012; Anderson, K. (2011) "Climate change going beyond dangerous – Brutal numbers and tenuous hope or cognitive dissonance", presentation 5 July 2011, slides available at http://www.slideshare.net/DFID/professor-kevin-anderson-climate-change-going-beyond-dangerous; plus (7) above.

More extreme weather can be expected

The heaviest rains and floods in 120 years have hit Serbia and Bosnia this week, Reuters and Deutsche Welle report.

The animation below shows the Jet Stream's impact on the weather. Cold temperatures have descended from the Arctic to Serbia and Bosnia in Europe and all the way down to the Gulf of Mexico in North America, while Alaska, California, and America's East Coast are hit by warm temperatures. In California, 'unprecedented' wildfires and fierce winds lead to 'firenadoes', reports CNN.

The image below shows that on May 15, 2014, the wind approaching Serbia and Bosnia at 700 hPa reached speeds of up to 120 km per hour (75 mph), as indicated by the green circle on the main image and inset.

The image below, from skeptical science, shows the cyclonic spin that can be expected in a through such as the one that hit Serbia and Bosnia recently.

As the Jet Stream changes, more extreme weather events can be expected. What makes the Jet Stream change? As the Arctic is warming up faster than the rest of the world, the temperature difference between the Arctic and the equator decreases, in turn decreasing the speed at which the Jet Stream circumnavigates the globe. This can cause 'blocking patterns', with extreme weather events hitting an area longer than before.

As the jet stream becomes wavier, cold air can more easily descend from the Arctic down to lower latitudes in a downward through of the Jet Stream, while warm air can more easily reach higher latitudes in an upward ridge of the Jet Stream.

This spells bad news for many areas across the world that can be expected to be hit by more extreme weather events such as heatwaves, wildfires fuelled by stronger winds and more intense drought, storms and floods.

Heatwaves are a huge threat in the Arctic, especially when followed by storms that can cause warm surface water to mix down to the bottom of the sea and warm up sediments under the seafloor that can contain huge amounts of methane in the form of hydrates and free gas. The situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog.


Related

- Extreme weather strikes around the globe - update
http://arctic-news.blogspot.com/2014/02/extreme-weather-strikes-around-the-globe-update.html

- Escalating extreme weather events to hammer humanity (by Paul Beckwith)
http://arctic-news.blogspot.com/2014/04/escalating-extreme-weather-events-to-hammer-humanity.html

- Our New Climate and Weather (by Paul Beckwith)
http://arctic-news.blogspot.com/2014/01/our-new-climate-and-weather.html

- Our New Climate and Weather - part 2 (by Paul Beckwith)
http://arctic-news.blogspot.com/2014/01/our-new-climate-and-weather-part-2.html

- Changes to Polar Vortex affect mile-deep ocean circulation patterns
http://arctic-news.blogspot.com/2012/09/changes-to-polar-vortex-affect-mile-deep-ocean-circulation-patterns.html

- Polar jet stream appears hugely deformed
http://arctic-news.blogspot.com/2012/12/polar-jet-stream-appears-hugely-deformed.html

Post by Sam Carana.

Outlook for sea ice remains bleak

In April 2014, Arctic sea ice reached its annual maximum volume. It was the second lowest on record, according to calculations by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center. The ice volume in March 2014 also was the second lowest on record, as discussed in an earlier post. The fall in volume over the years is illustrated in the graph below, by Wipneus.

Another way of depicting the continuing fall in sea ice volume is the Arctic Death Spiral below, by Andy Lee Robinson.

The graph below, from the Danish Metereological Institute, shows mean temperatures that have been much higher than they used to be at higher latitudes. Mean 2 m temperatures for the region north of the 80th northern parallel as a function of the day of year are shown (red line), against the 1958 - 2002 mean (green line).

High levels of methane over the Arctic will have contributed to these high temperatures. Furthermore, the Jet Stream is changing as the difference in temperature between the Arctic and the equator decreases, causing more extreme weather events such as heatwaves and storms that could speed up the demise of snow and ice cover in the Arctic.

The graph below, by the Japan Aerospace Exploration Agency, shows that Arctic sea ice extent was 12,469,546 km² on May 8, 2014.

In addition, an El Niño event could cause even more ferocious heatwaves and storms to hit the Arctic. The image below, from IRI at Columbia University, shows that the chance of an El Niño event developing in the course of 2014 is close to 80%.

The outlook for the sea ice remains bleak and the possibility that a total collapse could occur in September calls for comprehensive and effective action, as discussed at the climate plan blog.

Post by Sam Carana.

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 keelingcurve.ucsd.edu. 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 feet	44689 feet	36850 feet	30569 feet	25543 feet	19819 feet	14383 feet	8367 feet	1916 feet
74 mb	147 mb	218 mb	293 mb	367 mb	469 mb	586 mb	742 mb	945 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.

Post by Sam Carana.