Augmenting rainfall probability to ward off long-term drought?

Despite the ridiculous pseudo controversy surrounding global warming in the public discourse, the reality is that global warming is real and has already significantly started influencing the global climate. One of the most important factors in judging the range and impact of global warming as well as how society should respond is also one of the more perplexing, cloud formation. Not only do clouds influence the cycle of heat escape and retention, but they also drive precipitation probability. Precipitation plays an important role in maintaining effective hydrological cycles as well as heat budgets and will experience significant changes in reaction to future warming largely producing more extreme outcomes with some areas receiving significant increases that will produce flash flooding whereas other areas will be deprived of rainfall producing longer-term droughts similar to those now seen in California.

At its core precipitation is influenced by numerous factors like solar heating and terrestrial radiation.1,2 Of these factors various aerosol particles are thought to hold an important influence. Both organic and inorganic aerosols are plentiful in the atmosphere helping to cool the surface of Earth by sunlight scattering or serving as nuclei support for the formation of water droplets and ice crystals.3 Not surprisingly information regarding the means in which the properties of these aerosols influence cloud formation and precipitation is still limited, which creates significant uncertainties in climate modeling and planning. Therefore, increasing knowledge of how aerosols influence precipitation will provide valuable information for managing the various changes that will occur and even possibly mitigating those changes.

The formation of precipitation within clouds is heavily influenced by ice nucleation. Ice nucleation involves the induction of crystallization in supercooled water (supercooled = a meta-stable state where water is in liquid form at below typical freezing temperatures). The process of ice nucleation typically occurs through one of two pathways: homogenous or heterogeneous. Homogeneous nucleation entails spontaneous nucleation within a properly cooled solution (usually a supersaturated solution of relative humidity of 150-180% with a temperature of around –38 degrees C) requiring only liquid water or aqueous solution droplets.4-6 Due to its relative simplicity homogeneous nucleation is better understood than heterogeneous nucleation. However, because of the temperature requirements homogeneous nucleation typically only takes place in the upper troposphere and with a warming atmosphere it should be expected that its probability of occurrence would reduce.

Heterogeneous nucleation is more complicated because of the multiple pathways that can be taken, i.e. depositional freezing, condensation, contact, and immersion freezing.7,8 Typically these different pathways allow for more flexibility in nucleation with generic initiation conditions beginning at just south of 0 degrees C and a relative humidity of 100%. This higher temperature fails to prevent nucleation because of the presence of a catalyst, a non-water based substance that is commonly referred to as an ice-forming nuclei (IN). Also heterogeneous nucleation can involve diffusive growth in a mixed-phase cloud that consumes liquid droplets at a faster rate (Wegener–Bergeron–Findeisen process) than super-cooled droplets or snow/graupel aggregation.9

Laboratory experiments have demonstrated support for many different materials acting as IN: different metallic particles, biological materials, certain glasses, mineral dust, anhydrous salts, etc.8,10,11 These laboratory experiments involve wind tunnels, electrodynamic levitation, scanning calorimetry, cloud chambers, and optical microscopy.12,13 However, not surprisingly there appears a significant difference between nucleation ability in the lab and in nature.8,10

Also while homogenous ice nucleation is exactly that, heterogeneous nucleation does not have the same quenching properties.8 Temperature variations within a cloud can produce differing methods of heterogeneous nucleation versus homogeneous nucleation producing significant differences in efficiency. For example not surprisingly some forms of nucleation in cloud formations are more difficult to understand like high concentration formation in warm precipitating cumulus clouds; i.e. particle concentrations increasing from 0.01 L-1 to 100 L-1 in a few minutes at temperatures exceeding –10 degrees C and outpacing existing ice nucleus measurements.14 One explanation for this phenomenon is the Hallett-Mossop (H-M) method. This method is thought to achieve this rapid freezing through interaction with a narrow band of supercooled raindrops producing rimers.15

The H-M methodology requires cloud temperatures between approximately –1 and –10 degrees C with the availability of large rain droplets (diameters > 24 um), but at a 0.1 ratio relative to smaller (< 13 um droplets).16,17 When the riming process begins ice splinters are ejected and grow through water vapor deposition producing a positive feedback effect increasing riming and producing more ice splinters. Basically a feedback loop develops between ice splinter formation and small drop freezing. Unfortunately there are some questions whether or not this methodology can properly explain the characteristics of secondary ice particles and the formation of ice crystal bursts under certain time constraints.18 However, these concerns may not be accurate due to improper assumptions regarding how water droplets form relative to existing water concentrations.15

One of the more important element of rain formation in warm precipitating cumulus clouds, in addition to other cloud formations, appears to involve the location of ice particle concentrations at the top of the cloud formation where there is a higher probability for large droplet formation (500 – 2000 um diameters).15 In this regard cloud depth/area is a more important influencing element than cloud temperature.19 In addition the apparent continued formation of ice crystals stemming from the top proceeding downwards can produce raindrop freezing that catalyzes ice formation creating a positive feedback and ice bursts.20

This process suggests that there is a sufficient replenishment of small droplets at the cloud top increasing the probability of sufficient riming. It is thought that the time variation governing the rate of ice multiplication and how cloud temperature changes accordingly is determined by dry adiabatic cooling at the cloud top, condensational warming, evaporational cooling at the cloud bottom.15 Bacteria also appear to play a meaningful role in both nucleating primary ice crystals and scavenging secondary crystals.7 Even if bacteria concentrations are low (< 0.05 L-1) the catalytic effect of nucleating bacteria produces a much more “H-M” friendly environment.

The most prominent inorganic aerosol that acts as an IN is dust commonly from deserts that is pushed into the upper atmosphere by storms.21,22 The principal origin of this dust is from the Sahara Desert, which is lofted year round versus dust from other origin points like the Gobi or Siberia. While the ability of this dust to produce rain is powerful it can also have a counteracting effect as a cloud condensation nuclei (CCN). In most situations when CCN concentration is increased raindrop conversion becomes less efficient, especially for low-level clouds (in part due to higher temperatures) largely by reducing riming efficiency.

The probability of dust acting as a CCN is influenced by the presence of anthropogenic pollution, which typically is a CCN on its own.23,24 In some situations the presence of pollution could also increase the overall rate of rainfall as it can suppress premature rainfall allowing more rain droplets to crystallize increasing riming and potential rainfall. However, this aspect of pollution is only valid in the presence of dust or other INs for if there is a dearth of IN concentration, localized pollution will decrease precipitation.25 Soot can also influence nucleation and resultant rainfall, but only under certain circumstances. For example if the surface of the soot contains available molecules to form hydrogen bonds (typically from available hydroxyl and carbonyl groups) with available liquid water molecules nucleation is enhanced.26 Overall it seems appropriate to label dust as a strong IN and anthropogenic pollution as a significant CCN.

In mineral collection studies and global simulations of aerosol particle concentrations both deposition and immersion heterogeneous nucleation appear dominated by dust concentrations acting as INs, especially in cirrus clouds.10,27,28 Aerosols also modify certain cloud properties like droplet size and water phase. Most other inorganic atmospheric aerosols behave like cloud condensation nuclei (CCN), which assist the condensation of water vapor for the formation of cloud droplets in a certain level of super-saturation.25 Typically this condensation produces a large number of small droplets, which can reduce the probability of warm rain (above freezing point).29,30

Recall that altitude is important in precipitation, thus it is not surprising that one of the key factors in how aerosols influence precipitation type and probability appears to involve the elevation and temperature at which they interact. For example in mixed-phase clouds, the top area increases relative to increases in CCN concentrations versus a smaller change at lower altitudes and no changes in pure liquid clouds.15,31 Also CCN only significantly influence temperatures when top and base cloud temperatures are below freezing.31 In short it appears that CCN influence is reduced relative to IN influence at higher altitudes and lower temperatures.

Also cloud drop concentration and size distribution at the base and top of a cloud determine the efficiency of the CCN and are dictated by the chemical structure and size of an aerosol. For example larger aerosols have a higher probability of becoming CCN over IN due to their coarse structure. Finally and not surprisingly overall precipitation frequency increases with high water content and decreases with low water content when exposed to CCNs.31 This behavior creates a positive feedback structure that increases aerosol concentration, so for arid regions the probability of drought increases and in wet regions the probability of flooding increases.

While dust from natural sources as well as general pollution are the two most common aerosols, an interesting secondary source may be soil dust produced from land use due to deforestation or large-scale construction projects.32-34 These actions create anthropogenic dust emissions that can catalyze a feedback loop that can produce greater precipitation extremes; thus in certain developing economic regions that may be struggling with droughts continued construction in effort to improve the economy could exacerbate droughts. Therefore, developing regions may need to produce specific methodologies to govern their development to ensure proper levels of rainfall for the future.

While the role of dust has not been fully identified on a mechanistic level, its importance is not debatable. The role of biological particles, like bacteria, is more controversial and could be critical to identifying a method to enhance rainfall probability. It is important to identify the capacity of bacteria to catalyze rainfall for some laboratory studies have demonstrated that inorganic INs only have significant activity below –15 degrees C.10,35 For example in samples of snowfall collected globally originating at temperatures of –7 degrees C or warmer a vast majority of the active IN, up to 85%, were lysozyme-sensitive (i.e. probably bacteria).36,37 Also rain tends to have higher proportions of active IN bacteria than air in the same region.38 With further global warming on the horizon air temperatures will continue to increase lowering the probability window for inorganic IN activity, thus lowering the probability of rainfall in general (not considering any other changes born from global warming).

Laboratory and field studies have demonstrated approximately twelve species of bacteria with significant IN ability spread within three orders of the gammaproteobacteria with the two most notable/frequent agents being Pseudomonas syringae and P. fluorescens and to a lesser extent Xanthomonas.39,40 In the presence of an IN bacterium nucleation can occur at temperatures as warm as –1.5 degrees C to –2 degrees C.41,42 These bacteria appear to have the ability to act as IN due to the existence of a single gene that codes for a specific membrane protein that catalyzes crystal formation by acting as a template for water molecule arrangement.43 The natural origins of these bacteria derive mostly from surface vegetation.

Supporting the idea of the key membrane scaffolding, an acidic pH environment can significantly reduce the effectiveness of bacteria-based nucleation.45,46 Also these protein complexes for nucleation are larger for warmer temperature nucleating bacteria, thus more prone to breakdown in higher acidic environments.44,46 Therefore, low lying areas that have significant acidic pollution like sulfurs could see a reduction in precipitation probability over time. Also it seems that this protein complex could be the critical element to bacteria-based nucleation versus the actual biological processes of the bacteria as nucleation was augmented even when the bacteria itself was no longer viable.46

Despite laboratory and theoretical evidence supporting the role of bacteria in precipitation, as stated above what occurs in the laboratory serves little purpose if it does not translate to nature. This translation is where a controversy arises. It can be difficult to separate the various particles within clouds from residue collection due to widespread internal mixing, but empirical evidence demonstrates the presence of biological material in orographic clouds.47 Also ice nucleation bacteria are present over all continents as well as in various specific locations like the Amazon basin.37,48,49

Some estimates have suggested that 10^24 bacteria enter the atmosphere each year and stay circulating between 2 and 10 days allowing bacteria, theoretically, to travel thousands of miles.50,51 However, there is a lack of evidence for bacteria in the upper troposphere and their concentrations are dramatically lower than those of inorganic materials like dust and soot.28,35,52 Based on this lack of concentrations questions exist to the efficiency of how these bacteria are aerosolized over their atmospheric lifetimes. One study suggests that IN active bacteria are much more efficiently precipitated than non-active IN bacteria, which may explain the disparity between the observations in the air, clouds and precipitation.53

Another possible explanation for this disparity is that most biological particles are generated on the surface and are carried by updrafts and currents into the atmosphere. While the methods of transport are similar to inorganic particles, biological particles have a higher removal potential due to dry or wet deposition due to their typical greater size. Therefore, from a nature standpoint bacteria reside in orographic clouds because they are able to participate in their formations, but are not able to reach higher cloud formations, so most upper troposphere rain is born from dust not bacteria.

Some individuals feel that the current drop freezing assays, which are used to identify the types of bacteria and other agents in a collected sample, can be improved upon to produce a higher level of discrimination between the various classes of IN active bacteria that may be present in the sample. One possible idea is to store the sample at low temperatures and observe the growth and the type of IN bacteria that occur in a community versus individual samples.54 Perhaps new identification techniques would increase the ability to discern the role of bacteria in cloud formation and precipitation.

Among the other atmospheric agents and their potential influence on precipitation potassium appears to have a meaningful role. Some biogenic emissions of potassium, especially around the Amazon, can act as catalysts for the beginning process of organic material condensation.55 However, this role seems to ebb as potassium mass fraction drops as the condensation rate increases.55 This secondary role of potassium as well as the role of bacteria may signal an important element to why past cloud seeding experiments have not achieve the hypothesized expectations.

The lack of natural bacteria input into higher cloud formations leads to an interesting question. What would happen if IN active bacteria like P. syringae were released via plane or other increased altitude method that would result in a higher concentration of bacteria in these higher altitude cloud formations? While typical cloud formation involves vapor saturation due to air cooling and/or increased vapor concentration, increased IN active bacteria concentration could also speed cloud formation as well as precipitation probability.

Interestingly in past cloud seeding experiments orographic clouds appear to be more sensitive to purposeful seeding versus other cloud formations largely because of the shorter residence times of cloud droplets.56,57 One of the positive elements of seeding appears to be that increased precipitation in the target area does not reduce the level of precipitation in surrounding areas including those beyond the target area. In fact it appears that there is a net increase (5-15%) among all areas regardless of the location of seeding.58 The previous presumption that there was loss appears to be based on randomized and not properly controlled seeding experiments.58

The idea of introducing increased concentrations of IN active bacteria is an interesting one if it can increase the probability of precipitation. Of course possible negatives must be considered for such an introduction. The chief negative that could be associated with such an increase from a bacterium like P. syringae would be the possibility of more infection of certain types of plants. The frost mechanism of P. syringae is a minor concern because most of the seeding would be carried out between late spring and early fall where night-time temperatures should not be cold enough to induce freezing. Sabotaging the type III secretion system in P. syringe via some form of genetic manipulation should reduce, if not eliminate, the plant invasion potential. Obviously controlled laboratory tests should be conducted to ensure a high probability of invasion neutralization success before any controlled and limited field tests are conducted. If the use of living bacteria proves to be too costly, exploration of simply using the key specific membrane protein is another possible avenue of study.

Overall the simple fact is that due to global warming, global precipitation patterns will change dramatically. The forerunner to these changes can already been seen in the state of California with no reasonable expectation for new significant levels of rainfall in sight. While other potable water options are available like desalinization, the level of infrastructure required to divert these new sources from origins source to usage points will be costly and these processes do have significant detrimental byproducts. If precipitation probabilities can be safely increased through new cloud seeding strategies like the inclusion of IN active bacteria it could go a long way to combating some of the negative effects of global warming while the causes of global warming itself are mitigated.



Citations –

1. Zuberi, B, et Al. “Heterogeneous nucleation of ice in (NH4)2SO4-H2O particles with mineral dust immersions.” Geophys. Res. Lett. 2002. 29(10). 1504.

2. Hung, H, Malinowski, A, and Martin, S. “Kinetics of heterogeneous ice nucleation on the surfaces of mineral dust cores inserted into aqueous ammonium sulfate particles.” J. Phys. Chem. 2003. 107(9):1296-1306.

3. Lohmann, U. “Aerosol effects on clouds and climate.” Space Sci. Rev. 2006. 125:129-137.

4. Hartmann, S, et Al. “Homogeneous and heterogeneous ice nucleation at LACIS: operating principle and theoretical studies.” Atmos. Chem. Phys. 2011. 11:1753-1767.

5. Cantrell, W, and Heymsfield, A. “Production of ice in tropospheric clouds. A review.” American Meteorological Society. 2005. 86(6):795-807.

6. Riechers, B, et Al. “The homogeneous ice nucleation rate of water droplets produced in a microfluidic device and the role of temperature uncertainty.” Physical Chemistry Chemical Physics. 2013. 15(16):5873-5887.

7. Cziczo, D, et Al. “Clarifying the dominant sources and mechanisms of cirrus cloud formation.” Science. 2013. 340(6138):1320-1324.

8. Pruppacher, H, and Klett, J. “Microphysics of clouds and precipitation.” (Kluwer Academic, Dordrecht. Ed. 2, 1997). pp. 309-354.

9. Lance, S, et Al. “Cloud condensation nuclei as a modulator of ice processes in Arctic mixed-phase clouds.” Atmos. Chem. Phys. 2011. 11:8003-8015.

10. Hoose, C, and Mohler, O. “Heterogeneous ice nucleation on atmospheric aerosols: a review of results from laboratory experiments.” Atmos. Chem. Phys. 2012. 12:9817-9854.

11. Abbatt, J, et Al. “Solid ammonium sulfate aerosols as ice nuclei: A pathway for cirrus cloud formation.” Science. 2006. 313:1770-1773.

12. Murray, B, et Al. “Kinetics of the homogeneous freezing of water.” Phys. Chem. 2010. 12:10380-10387.

13. Chang, H, et Al. “Phase transitions in emulsified HNO3/H2O and HNO3/H2SO4/H2O solutions.” J. Phys. Chem. 1999. 103:2673-2679.

14. Hobbs, P, and Rangno, A. “Rapid development of ice particle concentrations in small, polar maritime cumuliform clouds.” J. Atmos. Sci. 1990. 47:2710–2722.

15. Sun, J, et Al. “Mystery of ice multiplication in warm-based precipitating shallow cumulus clouds.” Geophysical Research Letters. 2010. 37:L10802.

16. Hallett, J, and Mossop, S. “Production of secondary ice particles during the riming process.” Nature. 1974. 249:26-28.

17. Mossop, S. “Secondary ice particle production during rime growth: The effect of drop size distribution and rimer velocity.” Q. J. R. Meteorol. Soc. 1985. 111:1113-3324.

18. Mason, B. “The rapid glaciation of slightly supercooled cumulus clouds.” Q. J. R. Meteorol. Soc. 1996. 122:357-365.

19. Rangno, A, and Hobbs, P. “Microstructures and precipitation development in cumulus and small cumulous-nimbus clouds over the warm pool of the tropical Pacific Ocean. Q. J. R. Meteorol. Soc. 2005. 131:639-673.

20. Phillips, V, et Al. “The glaciation of a cumulus cloud over New Mexico.” Q. J. R. Meteorol. Soc. 2001. 127:1513-1534.

21. Karydis, V, et Al. “On the effect of dust particles on global cloud condensation nuclei and cloud droplet number.” J. Geophys. Res. 2011. 166:D23204.

22. Connolly, P, et Al. “Studies of heterogeneous freezing by three different desert dust samples.” Atmos. Chem. Phys. 2009. 9:2805-2824.

23. Lynn, B, et Al. “Effects of aerosols on precipitation from orographic clouds.” J. Geophys. Res. 2007. 112:D10225.

24. Jirak, I, and Cotton, W. “Effect of air pollution on precipitation along the Front Range of the Rocky Mountain.” J. Appl. Meteor. Climatol. 2006. 45:236-245.

25. Fan, J, et Al. “Aerosol impacts on California winter clouds and precipitation during CalWater 2011: local pollution versus long-range transported dust.” Atmos. Chem. Phys. 2014. 14:81-101.

26. Gorbunov, B, et Al. “Ice nucleation on soot particles.” J. Aerosol Sci. 2001. 32(2):199-215.

27. Kirkevag, A, et Al. “Aerosol-climate interactions in the Norwegian Earth System Model – NorESM. Geosci. Model Dev. 2013. 6:207-244.

28. Hoose, C, Kristjansson, J, Burrows, S. “How important is biological ice nucleation in clouds on a global scale?” Environ. Res. Lett. 2010. 5:024009.

29. Lohmann, U. “A glaciation indirect aerosol effect caused by soot aerosols.” Geophys. Res. Lett. 2002. 29:11.1-4.

30. Koop, T, et Al. “Water activity as the determinant for homogeneous ice nucleation in aqueous solutions.” Nature. 406:611-614.

31. Li, Z, et Al. “Long-term impacts of aerosols on the vertical development of clouds and precipitation.” Nature Geoscience. 2011. DOI: 10.1038/NGEO1313

32. Zender, C, Miller, R, and Tegen, I. “Quantifying mineral dust mass budgets: Terminology, constraints, and current estimates.” Eos. Trans. Am. Geophys. Union. 2004. 85:509-512.

33. Forester, P, et Al. “Changes in atmospheric constituents and in radiative forcing. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change.

34. O’Sullivan, D, et Al. “Ice nucleation by fertile soil dusts: relative importance of mineral and biogenic components.” Atmos. Chem. Phys. 2014. 14:1853-1867.

35. Murray, B, et Al. “Ice nucleation by particles immersed in supercooled cloud droplets.” Chem. Soc. Rev. 2012. 41:6519-6554.

36. Christner, B, et Al. “Geographic, seasonal, and precipitation chemistry influence on the abundance and activity of biological ice nucleators in rain and snow. PNAS. 2008. 105:18854. dio:10.1073/pnas.0809816105.

37. Christener, B, et Al. “Ubiquity of biological ice nucleators in snowfall.” Science. 2008. 319:1214.

38. Stephanie, D, and Waturangi, D. “Distribution of ice nucleation-active (INA) bacteria from rainwater and air, NAYATI Journal of Biosciences. 2011. 18:108-112.

39. Vaitilingom, M, et Al. “Long-term features of cloud microbiology at the puy de Dome (France). Atmos. Environ. 2012. 56:88-100.

40. Cochet, N and Widehem, P. “Ice crystallization by Pseudomonas syringae.” Appl. Microbiol. Biotechnol. 2000. 54:153-161.

41. Heymsfield, A, et Al. “Upper-tropospheric relative humidity observations and implications for cirrus ice nucleation.” Geophys. Res. Lett. 1998. 25:1343-1346.

42. Twohy, C, and Poellot, M. “Chemical characteristics of ice residual nuclei in anvil cirrus clouds: implications for ice formation processes.” Atmos. Chem. Phys. 2005. 5:2289-2297.

43. Joly, M, et Al. “Ice nucleation activity of bacteria isolated from cloud water.” Atmos. Environ. 2013. 70:392-400.

44. Attard, E, et Al. “Effects of atmospheric conditions on ice nucleation activity of Pseudomonas.” Atmos. Chem. Phys. 2012. 12:10667-10677.

45. Kawahara, H, Tanaka, Y, and Obata H. “Isolation and characterization of a novel ice-nucleating bacterium, Pseudomonas, which has stable activity in acidic solution.” Biosci. Biotechnol. Biochem. 1995. 59:1528-1532.

46. Kozloff, L, Turner, M, and Arellano, F. “Formation of bacterial membrane ice-nucleating lipoglycoprotein complexes.” J. Bacteriol. 1991. 173:6528-6536.

47. Pratt, K, et Al. “In-situ detection of biological particles in high altitude dust-influenced ice clouds.” Nature Geoscience. 2009. 2:dio:10.1038/ngeo521.

48. Prenni, A, et Al. “Relative roles of biogenic emissions and Saharan dust as ice nuclei in the Amazon basin.” Nat. Geosci. 2009. 2:402-405.

49. Phillips, V, et Al. “Potential impacts from biological aerosols on ensembles of continental clouds simulated numerically.” Biogeosciences. 2009. 6:987-1014.

50. Burrows, S, et Al. “Bacteria in the global atmosphere – Part 1: review and synthesis of literature data for different ecosystems.” Atmos. Chem. Phys. 2009. 9:9263-9280.

51. Burrows, S, et Al. “Bacteria in the global atmosphere – Part 2: modeling of emissions and transport between different econsystems.” Atmos. Chem. Phys. 2009. 9:9281-9297.

52. Despres, V, et Al. “Primary biological aerosol particles in the atmosphere: a review. Tellus B. 2012. 64:349-384.

53. Amato, P, et Al. “Survival and ice nucleation activity of bacteria as aerosols in a cloud simulation chamber.” Atmos. Chem. Phys. Discuss. 2015. 15:4055-4082.

54. Stopelli, E, et Al. “Freezing nucleation apparatus puts new slant on study of biological ice nucleators in precipitation.” Atmos. Meas. Tech. 2014. 7:129-134.

55. Pohlker, C, et Al. “Biogenic potassium salt particles as seeds for secondary organic aerosol in the Amazon.” Science. 2012. 337(31):1075-1078.

56. Givati, A, and Rosenfeld, D. “Separation between cloud-seeding and air-pollution effects.” J. Appl.Meteorol. 2005. 44:1298-1314.

57. Givati, A, et Al. “The Precipitation Enhancement Project: Israel - 4 Experiment. The
Water Authority, State of Israel. 2013. pp. 55.

58. DeFelice, T, et Al. “Extra area effects of cloud seeding – An updated assessment.” Atmospheric Research. 2014. 135-136:193-203.

Is it time to administer compulsory voting in the United States?

When looking at voting rolls regardless of the election period or environment, highly educated middle-aged working men are the most likely individuals to vote with various declining participation rates among other demographics.1,2 This decline is meaningful for voting in a democracy, either direct or indirect, is a direct representation of political power and influence. In addition as individuals become poorer and less educated their voting probability decreases.1 Not surprisingly research has demonstrated that politicians target their messages and actions towards those demographics that have the higher voting probabilities, regardless of whether or not those actions will produce the best outcomes for society in general.3 In some context politicians view their “constituents” as only those individuals who vote. Therefore, politicians will commonly ignore the concerns and problems of those individuals in demographics less likely to vote producing an environment that increases the probability of both income and social stratification.

To combat this aspect of inequality spread some individuals theorize that the United States should adopt compulsory (mandatory) voting over the current voluntary system. Compulsory voting is certainly not a new or exotic idea as 22 countries in the world already have some form of compulsory system including Australia and most of South America (assurance for those who only think such a system exists in 3rd world countries). Also compulsory voting has demonstrated a shift in public policy closer in line to the preference of citizens alleviating the divergence between citizen and constituent.4 So with the legitimacy of compulsory voting as an idea on sound footing, the question is should the United States change its current voting system as well?

Some voices may immediately suggest that the idea of compulsory voting is a direct challenge to individual freedom and liberty, thus should be rejected without discussion; these voices would belong to individuals who are either overreacting or foolish for the real issue is how one defines the role of voting in a society. This role can be defined as either a duty or a power. If defined as a duty then voting is regarded as a civic responsibility that one should engage in to justify his/her citizenship and contribution to society; therefore, compulsory voting should be viewed as reasonable and appropriate including any penalties associated with not voting. If defined as a power then voting is regarded as a means in which citizens can exert their influence on society, but voting should be regarded as only an opportunity not a requirement to express this power. However, it is important to note that in a voluntary voting structure if one chooses not to vote then one has no legitimacy in complaining about the current state of society.

When taking measure of most public discourse on this issue it appears that a majority would classify voting under the latter definition: a mandatory opportunity that a democracy must offer its citizens where participation is only voluntary. Unfortunately for those who hold this view such a belief is not so straightforward. A number of people appear to believe in the philosophy that individual decisions are made in a vacuum where that decision only affects that individual and not society as a whole. This mindset has produced the idea of a separation from society. For example some individuals have argued that if one does not ride public transit buses then that individual’s taxes should not go towards supporting the operation of buses. Clearly this makes little sense on a social level and if such an idea would be expanded beyond such a simple measure, which some would argue it should be, and applied to society as a whole then society would become extraordinarily complex and in general cease to function effectively producing a net negative to all parties. Therefore, one must consider measuring the voluntary nature of voting versus the good of society.

As mentioned above overall voting rates have fallen steadily and significantly over the last half century among all demographics sans the elderly (65+).5,6 Therefore, the possibility certainly exists that the United States’ democracy could become an oligarchy producing a singular path and set of cultural values. Regardless of one’s political leanings, there exists an extremely high probability that an oligarchy will be inherently negative to society producing significant societal disruption and inefficiency. With this potential reality the idea of voluntary voting could be dismissed in favor of compulsory voting under the idea of “for the good of society”. Understand that this mindset is not designed to produce a certain cultural/societal outcome, but instead to ensure sufficient representation. Basically it is akin to forcing Team A, B and C to play Team D in said sporting event. Forcing the game does not mean that Team D will lose, it just means that Team D will not win by forfeit.

Furthermore to those who argue that voting should be voluntary then it should follow that individuals should be given every convenience and opportunity to vote. Unfortunately the disheartening reality is that over the last decade certain actions have been taken in multiple states to increase the probability that citizens are denied the opportunity to vote or at least are given unjustifiable obstacles to overcome before having the opportunity. These actions raise the question of how could one support the idea of voting as a voluntary expression of citizenry power that is mandated by the government when the government and other private agencies work to limit the ability of citizens to vote? One of the guarantees of compulsory voting is that states and the Federal government would not have the ability to produce these additional obstacles to the process of voting and must produce an effective means to allow its citizens the opportunity to vote. The reality of the situation is that unless government, especially at the state level, can demonstrate an ability to produce appropriate voting opportunity compulsory voting may be necessary to ensure democracy in the United States.

To those who believe that applying compulsory voting is a ploy to increase the power base of one particular political viewpoint, current research demonstrates the uncertainty in the validity of this idea. Basically there is no significant difference between the preferences of voters and non-voters in already existing compulsory systems.7,8 In the United States it is thought that non-voters may slightly lean Democrat, but there is no certainty in this analysis for it is based on extrapolation from polling information and polling in general remains a foolish way for producing information as it is unreasonable to suggest that the views of five thousand people could properly characterize the views of fifty million. Therefore, at the current time there is no rational reason to conclude that compulsory voting in the United States would produce a significant power shift for one party over all of the others. Even if there was evidence to such a shift, what would be the problem for a democracy is supposed to be rule by the majority.

Even if compulsory voting were put into practice there are certain issues of access, functionality and penalties that must be considered. The issue of access is important for if government is going to demand that all citizens vote then it must make arrangement that all citizens have appropriate opportunity to do so. While a number of individuals have championed online voting as a means to produce ease of access, such claims produce equality and security concerns. Too frequently one hears about an individual or group hacking a corporation acquiring personal information and/or credit information to have sufficient confidence in the security of online voting and despite the mindset of certain technophiles not everyone has a personal at-home Internet connection or other means of access to the Internet that could effectively accommodate voting. (i.e. online access at a public library).

Therefore, with the uncertainty surrounding the use of Internet voting as nothing more than a luxury or advanced supplemental medium, local and state government must produce sufficient plans of action for in-person polling stations and voting by mail. Some could argue that in lieu of Internet voting, voting by mail is the next best thing. While having the option of voting by mail would be an important access element, eliminating in-person polling stations would not be the correct response. In past opinion polls voting by mail is constantly favored by wide margins over electrons that are run by mail.9,10

In a compulsory system exclusively relying on mail would also be extremely burdensome for the homeless. In addition there are some that are less confident that their vote will be counted when voting is performed through the mail.11 The Washington State system appears to be a good starting point for a national “vote by mail” system where the ballot is sent weeks ahead of time allowing the voter ample time to inform him/herself regarding the important issues and cast their ballot when convenient versus under a specific time crunch. However, there are still in-person stations available for use if an individual is uncomfortable or unable to cast their vote by mail. Whether or not early in-person voting would still be required under a compulsory system is unknown, but weighing on the side of caution to ensure sufficient voting opportunity in the first few elections it should be expected that counties offer early in-person voting for at least two days prior to Election Day.

From a functional standpoint one must address the mindset of those individuals who have previously not elected to vote. Once those with access issues are eliminated, the principal reason that individuals do not vote is that they suffer from a nihilistic mindset, i.e. they do not believe that their vote will matter. A similar mindset is that of the “forsaken voter”. An example of this mindset is seen in one of the major complaints of blacks and environmentalists, that the Democratic Party does not respect their opinions because Democratic leadership believes that these groups have nowhere else to go if they want to advance their political beliefs; they can’t vote for a Republican because that would be self-defeating, if they are real Democrats, and they can’t vote for a Green party member or other third party because of the infinitesimal probability that the person would actually win. Therefore, both types of individuals can feel that their “expression of power” through the vote is pointless.

So the chief question on this issue becomes how to manage those individuals who in the past decided not to vote because of the belief that it did not matter when they are now forced to vote or accept a penalty? Various other countries handle this issue with the straightforward opinion of allowing voters to cast their vote for a “none of the above”, which is thought to represent the dissatisfaction of that voter with the existing candidates. While this option is viable, it does not appear to be meaningful. On its face it can easily be argued that casting a vote for “none of the above” is pointless because it defeats the point of compulsory voting. What is the point of an individual spending any financial or opportunity cost voting if one is not going to cast a meaningful vote? Note that allowing a voter to merely leave a ballot blank is akin to selecting a “none of the above” option.

Individuals in favor of this option would argue that casting a vote for “none of the above” is a demonstration of dissatisfaction with the existing candidates and their respective platforms. Under this mindset a stronger message is sent to the political establishment by voting “none of the above” versus voting for “the lesser of two evils”. It could be argued that eliminating this option would be detrimental to producing efficiency in democracy because it would restrict choice.

The counterargument to this point is that while hypothetically it is a valid argument, in actual practice the problem with abstention is that it does not send that dissatisfied message or any meaningful message beyond a potential sound bite for the given election season. For example in the current election environment even if 75% of the citizenry abstained from an election those abstentions do not matter because the election will be decided on the votes of the 25% that did vote. There is no rule in U.S. election politics that voids an election if less than x% of the potential electorate actually votes, thus abstaining does not send a message because abstention produces no consequence to the candidates or the system. In essence no one in power would care that x% of the electorate was “dissatisfied” with the existing candidate pool. Realistically a “none of the above” vote will not demonstrate meaningful dissatisfaction with the available candidates, but simply disrespect for the process.

Furthermore there is a legitimate question to whether or not the administration of compulsory voting will lead to greater feelings of disillusionment with voting in general because with more people voting each individual vote has less power/influence. On its face whether or not this change is a significant psychological issue will more than likely be entirely influenced by both which candidate wins and the size of the victory. In this structure there are four possible outcomes for individual A and his vote: 1) votes for the winner in a landslide; 2) votes for the winner in a close result; 3) votes for the loser in a close result; 4) votes for the loser in a landslide;

Of these four possible outcomes the only one that could increase voter dissatisfaction is the third outcome where the preferred candidate loses by a small amount. In this situation the voter may interpret compulsory voting as costing their candidate the election naturally presuming that more “forced” participants voted for the opponent swaying the final result. However, in all other situations compulsory voting should have no effect or a positive effect on the viewpoint of voting. In the first outcome individual A should be inspired by compulsory voting in witnessing how many individuals agree with his viewpoint and the candidate that supports it. In the second outcome individual A could reason that compulsory voting was the reason for victory (the opposite rationality of the third outcome in that the “forced” participants swayed the final result in his favor). Finally in the fourth outcome there should be no change in opinion because the candidate lost big and would have lost big even if compulsory voting did not exist.

Some individuals have the belief that compulsory voting will have a positive impact on non-voting forms of political involvement and understanding. While this belief may be true the overall ability to produce this result would more than likely be marginalized by allowing for a simple “none of the above” option for it allows an individual to put no thought into the process at all and simply use the “I don’t care” option. If the idea of compulsory voting is to maximize the potential political power of the electorate then the process should not allow for the ability to so easily circumvent that idea. In addition the increased probability of political engagement must involve a change in the general human personality involving the “blind” rejection of ideas that are counter to their personal beliefs; if one is unable or unwilling to abandon incorrect opinions when faced with critical flaws of those opinions then increased political engagement is not be positive and very well could be a net negative.

There is a valid argument that can be made in favor of abstention on the basis that no individual should feel obligated or forced to vote for a particular individual or group just because voting is required. How can this conflict between the negative of allowing a “none of the above” option and forcing an undesired vote be resolved? One possibility is that voting individuals who do not prefer any of the candidates could write a brief explanation (1-2 sentences) regarding why he/she does not want to vote for the available candidates for a given elected position. This way the individual would be successfully abstaining while also demonstrating thoughtful respect for the voting process and increasing the slim probability that the dissatisfaction would actually be noted. Incidentally it would be preferred if these individuals would express this dissatisfaction to potential third party representatives so an individual that they would feel comfortable voting for could properly enter the race.

This aforementioned society-dissociated mindset can be detrimental to a compulsory voting scheme because without a reasonable probability that these “new” voters are properly informed their votes will not properly convey their own opinions or the representative opinion of society. For example suppose Apartment Complex A is having a vote among its 50 residents on whether or not to establish a new more restrictive noise ordinance. 10 residents are opposed to this new ordinance because they commonly have parties that involve loud music. 20 residents are in favor of this new ordinance because they are frequently bothered by the noise from these parties. The final 20 residents have no strong opinions on this vote and are not aware of the grievances of 20 pro ordinance residents because they are far enough away that they do not experience the loud music. Under these conditions these final 20 residents should abstain because of their lack of interest and information.

However, in a compulsory voting environment it is more than likely that they will vote against the ordinance due to reasons of either simplicity or avoiding future restrictions on themselves. Therefore, these 20 “neutral and uninformed” voters could improperly swing the results of the vote because they do not understand how the outcome of the vote affects all residents in Apartment Complex A. So if compulsory voting is applied making sure that all have access to the necessary resource to properly inform themselves of the issues is critical. Again it is fine if these last 20 residents vote against the ordinance if they are properly informed on how it will affect all parties, it is the ignorance that must be defeated.

With regards to penalties, most compulsory voting practicing countries administer a small financial penalty when an individual fails to vote. Interestingly enough this penalty is typically equal to or less than a standard parking violation, which does not send a strong message that voting is important. Clearly administering large fines would be questionable akin to issuing a $10,000 dollar speeding ticket making such a strategy difficult. A better means to “encourage” compliance with compulsory voting would be to administer time penalties that have direct societal duty elements for most people tend to value their time over small generally meaningless amounts of money. For example failure to vote should be met with community service penalties or an increased probability for jury selection. Regarding possible exemptions from voting realistically if the proper access systems are developed, which they should be, then few possibilities remain. One legitimate exemption could be on the basis of religious grounds, i.e for Jehovah’s Witnesses, etc. Another exemption could be given for those suffering from mental illness or even at an advanced age (70+).

One potential side problem in a compulsory voting environment is the issue of whether or not individuals will be more inclined to buy/sell votes. With a mandate that every citizen vote the probability of voter fraud will still be low due to proper checks and security measures. However, what cannot be so easily neutralized are individuals selling their votes. Selling votes may not be a large issue now as the rationality behind its absence is the lower voter turnout, thus groups merely have to “rally” the “Parisians” to drive their chances of winning. Under a mandate there will be a much larger pool of potential voters that would be more difficult to directly persuade, thus shortcuts could be taken. It is also important to note that there is a reasonable probability that a number of these “new” voters could be politically apathetic enough to sell their vote. Fortunately due to the privacy associated with voting it would be extremely difficult for the “vote buyer” to confirm that the “vote seller” actually voted the way he/she may have been instructed to, thus without the ability to confirm both sides of the exchange, vote buying and selling should be limited, if any occurs at all. Also there has been no widespread vote buying in other compulsory voting countries.

The idea of compulsory voting should be one of irrelevance for all citizens should be interested enough in the development of society that they at least spend a few moments understanding the pertinent issues and then proceed to vote on their beliefs. However this mindset is far from universal. While this reality is unfortunate it could be sufficiently dismissed as regretful, but not critical if not for two salient points. First, and most important currently, certain agencies are actively attempting to prevent certain groups of individuals from voting by producing unnecessary obstacles. These actions directly threaten the idea of voluntary voting as a sufficient means for citizens to express their power as a citizen of a democracy. Second, there are times when individual privileges need to be augmented for societal good and the preservation of a democracy over an oligarchy certainly meet the condition of societal good. Overall the idea of compulsory voting is not one that aims to force democracy upon its citizenry, but instead protect democracy for its citizenry.


Citations –

1. Kittelson, A. Book chapter: The Politics of Democratic Inclusion. In - The politics of democratic inclusion. Temple University Press, 2005.

2. Blais, A, Gidengil, E, and Nevitte, N. “Where does turnout decline come from?.” European journal of political research. 2004. 43(2):221-236.

3. Verba, S. “Would the dream of political equality turn out to be a nightmare?.” Perspective on Politics. 2003. 1(4):663-679.

4. Fowler, A, “Electoral and policy consequences of voter turnout: evidence from compulsory voting in Australia.” Quarterly Journal of Political Science. 2013. 8:159-182.

5. U.S. Census Bureau, Current Population Survey, November 2008 and earlier reports. Internet release data: July 2009. Table A-1. Reported Voting and Registration by Race, Hispanic Origin, Sex and Age Groups: November 1964 to 2008.

6. U.S. Census Bureau, Current Population Survey, November 2008 and earlier reports. Internet release data: July 2009. Table A-2. Reported Voting and Registration by Region, Educational Attainment and Labor Force for the Population 18 and Over: November 1964 to 2008.

7. Citrin, J, Schickler, E, and Sides, J. “What if everyone voted? Simulating the impact of increased turnout in senate elections.” American Journal of Political Science. 2003. 47(1):75-90.

8. Pettersen, P, and Rose, L. “The dog that didn’t bark: would increased electoral turnout make a dif
ference?” Electoral Studies. 2007. 26(3):574-588.

9. Alvarez, R, et Al. “The 2008 Survey of the Performance of American Elections.” Washington, DC: Pew Center on the States. 2009.

10. Milyo, J, Konisky, D, and Richardson, L. “What determines public approval of voting reforms?” Paper presented at the Annual Meeting of the American Political Science Association, Toronto, Canada. 2009.

11. Alvarez, R, Hall, T, and Llewellyn, M. “Are Americans confident their ballots are counted?” Journal of Politics. 2008. 70:754-768.