To grow or not to grow: the dilemma of sustainability

. The premises and conclusions of the Science and the Future conference held in 2013 are the basis for this paper. I shall describe the changes occurred in the world since 2013 to present both on the positive and on the negative side, together with the failures to change, that will be discussed during the present conference. I shall especially point out the failure to address the contradiction between material growth and sustainability. The limit posed by the growing complexity of the global economy will be demonstrated, showing its implications for the ungovernability of the system. I will stress the difficulty and urgency of a fully rational analysis and the discussion of some strongholds of the present social paradigm, which are intrinsically entangled with human and material unsustainability .


Foreword
Five years ag (ctber 2013) I had the priviege t pe the first editi f Sciece ad the Future The purpse f that cferece was t discuss the prbes ad ctradictis ipied i the the gig treds f the wrd ecy The startig pit was the criticaities ad icsistecies pited ut frtytw years earier i The iits t Grwth prted by the Cub f Re 1 Sciece ad the Future 2 wi be hed i the year f the fiftieth aiversary f the Cub f Re fuded i 1968 by Aurei Peccei David Rcefeer ad Aexader ig ad is a pprtuity t exaie the wrd's evuti i recet years Pepe's awareess f the prbes huas are facig is prbaby higher w tha it was fifty years ag I 2015 the U cferece  ciate chage was hed i Paris ad a iprtat pricipe agreeet was siged there (s far ratified by 197 states) The edia fte cvey aarig essages t the geera pubic regardig the disasters f the ciate chage ad ciate chage deiers have itte evidece t supprt their psiti ad a sa audiece At first sight we are w i a better psiti t face the chaege f the csequeces f ur gbay usustaiabe way f ife Despite a this hwever ig at gba physica paraeters suggests that itte has chaged r i ther wrds that the gba situati has csideraby wrseed i ay respects ature is fferig icreasig evidece that we are gig the wrg way Fds i deserts such as thse i Petra (rda) i 2018 ad recurrig fires i Caifria ad ther parts f the wrd ca hardy be csidered rdiary uucy evets 2 State of the world

Energy
Csiderig the treds i wrd eergy csupti (see Figure 1) the y evidece fr a teprary decrease i dead is visiby a csequece f the recessi which rigiated with the scaed subprie rtgage crisis i the years after 2007 As s as the egie f the d car ffered sigs f recvery treds apparety resued their d curse The average csupti rate grew by 22% fr 2016 t 2017 whereas the average yeary grwth i the previus decade had bee i the rder f 17% These ubers tes us that the wrd eergy dead is t a csequece f cscius picies but rather f the w echaiss f the busiessasusua ecy Another remarkable figure is that 81% of energy is obtained from fossil sources and 10% from biomass: altogether 91% comes from combustion processes, even though, in the case of biomass, this could be in a circular and, in principle, sustainable way.

CO 2 emissions
The treds i C2 eissis ( Figure 2) are eve re istructive their cecti with the ups ad dws f the wrd ecy is evidet Swdws i grwth crrespd t wer C2 eissi rates At the begiig f 2018 ratig agecies ad ecica peratrs decared the wrd ecy t be grwig agai after a few years f ricety evuti ad the 2017 carb dixide eissi rate crrespdigy tured ut t be 22% higher tha i 2015 There is  evidece fr ay effective ctaiet picies aywhere i the wrd

Mass migrations
Tgether with the physica aspects f gba chage we fid as ther hua pheea beig itred ad fr which urget actis are eeded These are cficts ad ass igratis these tpics wi be discussed i ther ctributis t this cferece Here I sipy draw atteti t the treds ad dyaics f igrati fuxes Fig 3 igrati fuxes i the ECD area durig a recet deceia Figure 3 presets the situati i the 36 cutries that are part f the ECD (12 bii ihabitats atgether) The uber f peraet igrats has icreased sice 2011 There are utipe causes drivig pepe t eave their he cutries ad see their frtue esewhere Basicay f curse everybdy ais t iprve their cditi but st fte pepe fid they have t ve due t iediate ad draatic pushes war disasters r ther causes f despair Gba ciate chages are at the rigi f ay f these eergecies water shrtages decreasig si fertiity ad recurret extree weather evets These eergecies a have re acute repercussis  pr pepes ad atis causig pepe t resrt t fight ad igrati Cficts ad ciate chage wi bth be deat with i this cferece I wi fcus  the differeces that are iheret i the gba ecy ad cuped with ther drivers ve desperate crwds t areas with arratives that have apparety ed t re pprtuities

Inequalities
Iteratia bservers w that ice iequaities are ideed grwig everywhere i the wrd with y ca ad iited exceptis Figure 4 presets exapes f a few deveped cutries but the phee is wider tha this the treds bega at the ed f the 1970s Fig 4 Share f ice eared by the richest 1% f the ppuati i seve cutries There are udubtedy ay irreguarities ad huge differeces ag cutries but the tred fr a is twards grwth This is ideed a serius prbe ad pepe are geeray wrried abut hw t cure this evidet scia disease hwever if we wish t cure a iess we ust first idetify its causes ad this eas havig a cser  at the very fudati f the preset gbaised ecy Uavidaby we have t ce bac t the sacred ster that has bee at the cetre f the scee fr the ast cupe f ceturies grwth

Limits and constraints
The axis at the base f the stadard ecic dctrie are essetiay grwth ad cpetiti The stadard cvicti is that the reedy fr ice iequaities is gba grwth if the ecy vera grws the every payer wi receive a advatage Pereia grwth is ideay described by a expetia curve Caig W the weath t the tie ad assuig a stabe grwth rate per uit tie α it wud be t e W W α 0 = (1) If we apply (1) to the personal income of two subjects, A and B, starting at W 0A and W 0B and growing at the same rate, it is immediately clear that the ratio between the incomes W A /W B stays fixed while time passes, but the absolute value of the difference grows at the same rate as the incomes grow. In practice this kind of growth freezes the social pyramid, but the quantitative increase of the differences is likely to be increasingly troublesome.
A friendlier social version of economic growth advocates differential growth: lower incomes should increase faster than higher, and in this way the difference may be reduced. Such differential growth does not happen spontaneously, which means that the state must intervene in order to regulate and direct an economy towards this social rebalancing goal. The problem is: how long a state is in the condition to promote such a policy. The task is also difficult considering that those who have high income usually have also a stronger influence over public powers.
In any case the basic assumption for all the above approaches is the myth of perpetual growth. The real world, however, tells us a different story: perpetual material growth in a finite environment is impossible. This obvious fact has been known for a very long time and has been brought to the attention of the general public and of decision makers for fifty years, but the idea of a constraint like that is in fact, explicitly or implicitly, and in any case vehemently, rejected by the economic establishment.
In fact, in the best abstract conditions a finite growth process cannot develop along an exponential (as in Formula 1), but evolves following a trend described reasonably well by a logistic curve: W M is the maximum attainable value (in an infinite time); the other parameters involve the assumed value at time t = 0 (a), and with the slope of the curve.
A typical logistic like (2) is shown in Figure 5. The units in the figure are arbitrary and the asymptotic maximum is normalised to 1; the initial (t = 0) value is a bit less than 20% of the asymptote. This type of evolution recalls the growth of trees: in principle it goes on forever but the growth rate diminishes continuously toward zero.
If we now add the other typical ingredient of the business-as-usual doctrine, i.e. competition, to the axiom of growth, then what happens to inequalities? Consider two players, one of whom has an initial advantage. Each one tries to convert the available primary resources into personal wealth, but the stock of raw material is altogether finite. If, on a first optimistic approach, we suppose that both contenders act independently, but in any case working on what is freely available, the dynamics for everyone are similar to the logistic evolution, but the "roof" is not simply the physical asymptote: it is the finite physical provision diminished by what already belongs to the other competitor. If so, both players grow towards different asymptotic upper values and the same happens to the difference between them, which also follows a logisticlike evolution: continuous decelerated growth.
A more realistic approach sees that those at the top, while competing and winning, incorporate part of the wealth initially produced and owned by the lower competitor. In this way, the upper player faces the total amount of physically available resources, whilst the roof for the lower contender is the physical limit minus what is in hands of the stronger competitor. In this case the result is that shown in Figure 6: the weakest (lower curve), after a while, stops growing and its condition worsens, while the strongest continues to tend to the asymptote. We could call it the Monopoly Game Diagram. Fig. 6. Effect of growth combined with competition in a finite environment. The weakest (lower curve), after a while, stops growing and its condition worsens, while the strongest continues to tend to the asymptote.
Of course reality is much more complicated than a simple two-player scheme, but the essential mechanisms are the same and the expected evolution is reasonably well represented in Figure 6.

Costs
The situati described i the previus secti is ideed abstract ad ideaised because it assues the effect f csts r i geera f egative feedbac that cat i ay case be eiiated (secd pricipe f therdyaics) is exacty caibrated i rder t t stp but sipy t sw dw the grwth prcess re ad re effectivey The rea wrd ca be represeted by tw sipe exapes brrwed fr physics The first ivves h's ad ue's aws h's aw tes us that a advatage i the fr f a eectric curret I is directy prprtia t its cause the ptetia differece V betwee the eds f a cductive wire ue's aw wars us that the side effect f the fwig curret W (the heatig f the cductig cabe) is prprtia t the square f the vtage The sae as hds true fr ateria fws ad fr the veet f a bect The etu p is prprtia t the speed v (p  v) but the ietic eergy is prprtia t the square f v T  v 2 2 The effrt eeded t icrease the speed grws faster tha the speed ad if a crash ccurs the the eergy t be dissipated the daage t dea with icreases quadraticay with the vecity These trivia but at the sae tie uiversa rears have t be added t the fact that the ecic syste is a cpex etwr ad that the cpexity grws quadraticay whe the uber f ts i the et grws This issue was discussed i the first editi f Sciece ad the Future (2013) ad i 2 Suarisig everythig i e setece ad startig fr the ptia gistic tred fr grss beefits ( Figure 5) csts (whatever they are) grw faster tha advatages Csequety the et gai i the grwig syste evves as i Figure 7 rather tha Figure 5 Fig 7 Evuti f et gais i tie fr a grwig syste This tred as has t be tae it accut whe discussig ice iequaities ad the resut is a further wrseig f the situati

Conclusion
I suary we have see that the physica cues we ceary read arud us idicate that despite the gig debate  gba chages iduced by hua behaviur the busiess as usua phisphy ctiues t prevai ad at the sae tie the csequeces f the chages bece re ad re cpeig Furtherre they are re heaviy fet by the prest f the wrd Appyig sipe ratia arguets based  physica prperties ad cstraits we saw that the trubes huaity has t face are the ecessary csequeces f the paradig f grwth ad cpetiti f curse techgy ad sciece ca hep i itigatig the ipact f gba chage ad brigig the situati uder ctr but we shud avid attributig agica pwers t sciece Irratiaity is sti very strg ad especiay  the side f the decreasig uber f hua beigs wh have the biggest advatages a attepts t reegtiate the cditis f the scia pact have bee viety ad stubbry reected Ufrtuatey hwever we are a  the sae ad uique paet ad we shud strive fr the best fr everybdy Sciece shws that irratia egis is t the right egie f prgress fr huas