350,000 Marchers = 50 Parts Per Million

People's Climate March, New York, September 21, 2014, photo by Cindy Snodgrass

by Nathan Currier

How big a deal was the march in Manhattan yesterday? One of the organizers was 350.org, a group started by Bill McKibben based on a paper by climate scientist James Hansen which stated that we should aim for about 350 parts per million (ppm) CO2. We are currently at about 400ppm, so we need to move "only" about 50ppm in the opposite direction from our rapid growth, which hit a frightening 3ppm clip last year.

It will take a huge effort, and few alive today will live to see it (short of large-scale engineering), but it is interesting to ponder the minute change this represents in the air -- a shift of just 5 one-thousandths of one percent (.005 percent) of the atmosphere! That is one of the fascinating things in climate science, how such a minute change in our atmosphere could potentially have such an impact on the energy balance of our whole planet.

Keep this in mind if you are trying to contemplate how big a deal it is that some 350,000 people came out into the streets of Manhattan, the capital of capitalism, the cultural heart of the nation where manufactured denial has most stymied action. That's because this happens to be exactly the same proportion of the 7 billion members of humanity, 5 one-thousandths of one percent, as that 50ppm is a shift in the composition of the air. Further, some have estimated the real number of marchers as 400,000, and if the global estimates swell equally, then globally about the same proportion were marching as the CO2 growth since industrialization is a shift in atmospheric composition. In a way, all those marching were just a trace, and as soon as we dissipated into streets and subways afterwards, quickly outnumbered by people going about their everyday lives, that seemed obvious, but in another way, how monumental the right little trace can become!

And speaking of powerful little traces, methane is even far less concentrated in the air than CO2, about 220 times less so, but there was really some methane floating around the Manhattan air yesterday! No, I don't mean all those leaky pipes in the city that have led local tests to sometimes register incredibly high ambient readings of the greenhouse gas. I mean that among the marchers anti-fracking signs often seemed to outnumber all other "sub-theme" signs. This is a fascinating phenomenon, as some of us have felt that, since we all ultimately must live in the here and now, and since one cannot impact the climate we have here and now very effectively through CO2 mitigation, yet one can only gain practical political traction by dealing with that here and now, so one of the best ways to gauge seriousness in getting movement going on climate would be to watch for meaningful action on methane. In a sense, if you want people to start climbing up a very steep ladder, you need to give them a nice low first step, and that first climate step would be methane. As Robert Watson, the previous Chair of the United Nation's Intergovernmental Panel on Climate Change put it succinctly, rapidly cutting methane, "would demonstrate to the world that we can do something to quickly slow climate change. We need to get moving to cool the planet's temperature. Methane is the most effective place for us to start."

The Manhattan climate march also provided a fitting example of how getting the big slow march of change rolling can be frustrating: for those in the back it took two hours to start any movement at all, and then another two hours to reach Columbus Circle, its ostensible starting point. Similarly inevitable drags on climate mitigation are making rapid methane action all the more important. And uncertainties in near-term climate change, with a rising potential for high-impact lower-probability events to cause abrupt heating (like non-human methane emissions in the arctic taking off more quickly than models predict), means that ignoring the near-term climate for too long could ultimately prove fatal to all our best intentions. So it's fascinating to see an interest in methane growing from the grass roots, even if it is still largely (and erroneously) confined to the fracking issue at this point. Let's hope that the interest in this merest little trace gas of our air -- since industrialization it has risen by about 1.1 ppm, a shift of about 1.1 ten-thousandth of 1 percent of the atmosphere! -- sparks soon. The group 1250 was initially intended to provide a kind of autonomous offshoot to McKibben's 350, in order to help generate that spark, but McKibben himself soon said that he "had his hands full with CO2" and did not at the time send along to his followers the group's initial petition drive, which then quickly languished. But if methane interest does reach that critical concentration, and that spark is provided, you know what happens next: that's when climate action goes boom.

Above text was earlier posted by Nathan Currier at the HuffingtonPost 

Below follow further photos by Cindy Snowgrass of the People's Climate March.

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.

Turning forest waste into biochar

Too much biomass waste in tundra and boreal forests makes them prone to wildfires, especially when heatwaves strike. Furthermore, leaving biomass waste in the forest can cause a lot of methane emisions from decomposition.

In order to reduce such methane emissions and the risk of wildfires, it makes sense to reduce excess biomass waste in fields and forests. Until now, this was typically done by controlled burning of biomass, which also causes emissions, but far less than wildfires do. Avoiding wildfires is particularly important for the Arctic, which is vulnerable to soot deposits originating from wildfires in tundra and boreal forest. Such soot deposits cause more sunlight to be absorbed, accelerating the decline of snow and ice in the Arctic.

A team of scientists at University of Washington, sponsored by the National Science Foundation, has developed a way to remove woody biomass waste from forests without burning it in the traditional way. The team has developed a portable kiln that can be assembled around a heap of waste wood and convert it to biochar on the spot, while the biochar can also be burried in the soil on the spot.

Demonstration in Kerby, Oregon,
Nov. 6, 2012,  by Carbon Cultures. 
Credit: Marcus Kauffman at Flickr

The team initially started testing the effectiveness of a heat-resistant blanket thrown over woody debris.  The team then developed portable panels that are assembled in a kiln around a slash pile.

Students have set up a company, Carbon Cultures, to promote the technology and to sell biochar. CEO of Carbon Cultures is Jenny Knoth, also a Ph.D. candidate in environmental and forest sciences.

The kiln restricts the amount of oxygen that can reach the biomass, which is transformed by pyrolysis into biochar. The woody waste is heated up to temperatures of about 1,100 degrees Fahrenheit (600 Celsius), as the kiln transforms some 800 pounds of wood into 200 pounds of biochar in less than two hours. “We also extinguish with water because it helps keep oxygen out and also activates the charcoal [making it more fertile in soil].”

Currently, the total costs of disposing of forest slash heaps (the collections of wood waste) approximate a billion dollars a year in the United States, according to Knoth.

And of course, adding biochar to the soil is a great way to reduce carbon dioxide levels in the atmosphere. “Biochar is proven to fix carbon for hundreds of thousands of years,” Knoth said.

Demonstration in Kerby, Oregon, November 6, 2012, organized by Carbon Cultures.  Credit: Marcus Kauffman at Flickr

As said, when biomass waste is left in the open air, methane emissions are produced during its decomposition. Moreover, such waste will fuel wildfires, which produce huge amounts of emissions. The traditional response therefore is to burn such waste. Pyrolyzing biomass produces even less greenhouse gases and less soot, compared to such controlled burning.

Biochar is produced in the process, which can be added to the soil on the spot. This will help soil retain moisture, nutrients and soil microbes, making forests more healthy, preventing erosion and thus reduces the risk of wildfires even further, in addition to the reduction already achieved by removal of surplus waste.

A healthy forest will retain more moist in its soil, in the air under its canopy, and in the air above the forest through expiration, resulting in more clouds that act as sunshades to keep the forest cool and return the moist to the forest through rainfall. Forests reinforce patterns of air pressure and humidity that result in long-distance air currents that bring moist air from the sea inland to be deposited onto the forest in the form of rain. Finally, clouds can reflect more sunlight back into space, thus reducing the chance of heatwaves.

References

- Recycling wood waste - The Daily of the University of Washington
- Helping Landowners with Waste Wood While Improving Agribusiness and Energy - National Science Foundation

Related

- Biochar
- CU-Boulder gets into biochar

- Fires are raging again across Russia
- Abrupt Local Warming

How much methane is located in the Arctic?

Arctic sources of carbon have been studied by a team of researchers at Lawrence Livermore National Laboratory, Livermore, California, United States, led by Joshuah Stolaroff. Their estimates are illustrated in the image below, showing the potential total release, next to their characteristic annual release of methane and the geographic extent for each source.

Stolaroff et al., 2012, DOI: 10.1021/es204686w 

Note: Numbers in brackets behind the figures in above table relate to references below. If you cannot view these references, click here. 


For comparison, the NOAA image below shows the world's carbon dioxide emissions for each year in PgC (i.e. GtC or billions of tonnes of carbon).

Annual total emissions. The bars in this figure represent carbon dioxide emissions for each year in PgC yr-1 from the specified region. The final bar, labeled 'Mean', represents the 2001-2010 average. CarbonTracker models four types of surface-to-amosphere exchange of CO2, each of which is shown in a different color: fossil fuel emissions (tan), terrestrial biosphere flux excluding fires (green), direct emissions from fires (red), and air-sea gas exchange (blue). Negative emissions indicate that the flux removes CO2 from the atmosphere, and such sinks have bars that extend below zero. The net surface exchange, computed as the sum of these four components, is shown as a thick black line. 

Clearly, if merely a fraction of the sources at the top would end up in the atmosphere, we'd be in big trouble. Some of the carbon may be released gradually in the form of carbon dioxide, but it's much worse if large amounts of methane escape abruptly into the atmosphere, given factors such as methane's high Global Warming Potential. Anyway, it should be clear that the huge size of some of these sources poses a terrifying threat.  

References

1. Boucher, O.; Folberth, G. A. New Directions: Atmospheric methane removal as a way to mitigate climate change? Atmospheric Environment 2010, 44, 3343 – 3345.
2. Solomon, S. et al. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change; Cambridge University Press: Cambridge, UK, 2007.
   http://www.ipcc.ch/publications_and_data/publications_ipcc_fourth_assessment_report_wg1_report_the_physical_science_basis.htm
3. Reagan, T. M.; Moridis, J. G.; Elliot, M. S.; Maltrud, M.; Cameron-Smith, P. Basin-scale assessment of gas hydrate dissociation in response to climate change. Proceedings of the 7th International Conference on Gas Hydrates (ICGH 2011), 2011.
   http://adsabs.harvard.edu/abs/2010AGUFMOS43B..08R 
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5. Heidel, K.; Holmes, G.; Singh, A.; D. Keith, D. Process Costing of A Contactor for Air Capture. 10th International Conference on Greenhouse Gas Control Technologies, Amsterdam, 2010.
   http://keith.seas.harvard.edu/Misc/Process simulation of direct CO2 capture from air.pdf
6. Stolaroff, J. K.; Keith, D. W.; Lowry, G. V. Carbon Dioxide Capture from Atmospheric Air Using Sodium Hydroxide Spray. Environmental Science & Technology 2008, 42, 2728–2735, PMID: 18497115.
   http://pubs.acs.org/doi/abs/10.1021/es702607w
7. Trenberth, K. E.; Smith, L. The Mass of the Atmosphere: A Constraint on Global Analyses. J. Climate 2005, 18, 864–875.
   http://journals.ametsoc.org/doi/abs/10.1175/JCLI-3299.1
8. Seinfeld, J. H.; Pandis, S. N. Atmospheric Chemistry and Physics; John Wiley and Sons: New York, 1998.
9. Massman, W. J. A review of the molecular diffusivities of H2O, CO2, CH4, CO, O3, SO2, NH3, N2O, NO, and NO2 in air, O2 and N2 near STP. Atmospheric Environment 1998, 32, 1111–1127.
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