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Water — Energy — Food Nexus

Earth sys­tems are com­plex, dynam­ic and inter-relat­ed in nature. And so are the prob­lems that the Earth is faced with today. We have often been seek­ing solu­tions that are sim­ple, easy and uni­di­men­sion­al. With the earth rac­ing towards becom­ing home to a 9 Bil­lion pop­u­la­tion by 2050 and increas­ing com­pe­ti­tion for land, water, resources and ener­gy, there are ris­ing con­cerns of glob­al food secu­ri­ty and increas­ing stress on water resources. Tra­di­tion­al pol­i­cy­mak­ing and gov­er­nance struc­tures have dealt with each of these in silos, not tak­ing into con­sid­er­a­tion their inter­con­nect­ed­ness. Even when it comes to indi­vid­ual action, the pop­u­lar solu­tions have been restrict­ed to To-Dos of switch­ing off lights to save ener­gy, not wast­ing food, and turn­ing off taps to save water. Agreed. All of these steps are impor­tant. But what if these con­sti­tute just the tip of the much larg­er ice­berg? The larg­er ice­berg of the Nexus between Food, Ener­gy, and Water?

The seem­ing­ly sim­ple sys­tems that exist around us are con­nect­ed to a deep­er net­work of depen­den­cies and that is why mov­ing away from deal­ing with sec­tors in iso­la­tion and mov­ing towards a Nexus approach is cru­cial. To achieve the three pil­lars of sus­tain­able devel­op­ment one such com­plex nexus lies at the crux: The Water-Ener­gy-Food nexus.

The hidden water in everything!

Every­thing you can see around has caused a sig­nif­i­cant amount of water to be extract­ed, con­sumed and pol­lut­ed in the process of mak­ing it. This is referred to as the Water Foot­print. The price tag decep­tive­ly reduces the prod­uct to only its eco­nom­ic val­ue, blur­ring out the ener­gy and water that has gone into mak­ing it. A sin­gle pair of jeans requires any­where between 6000 to 11,000 liters of water to make. How is that? The Water foot­print of the jeans takes into con­sid­er­a­tion the water that is need­ed to grow the cot­ton, wash it and dye it, along with the water con­sumed by all oth­er stages of its pro­duc­tion in between. We can use the same exam­ple to illus­trate three types of water foot­prints:

Green water foot­print: The evap­o­ra­tive flow of water that is used for human pur­pos­es (grow­ing cot­ton, in this case) which if left to itself would have oth­er­wise flowed in nat­ur­al sys­tems and nour­ished nat­ur­al ecosys­tems.

Blue water foot­print: The water with­drawn and con­sumed from aquifers, rivers or ground­wa­ter. In this case, for wash­ing the cot­ton, spin­ning and pro­cess­ing it.

Grey water foot­print: The water that is pol­lut­ed and released back into water bod­ies either direct­ly from the fac­to­ry or indi­rect­ly through dif­fu­sion or runoff, lead­ing to degra­da­tion in its qual­i­ty. In the case of jeans man­u­fac­tur­ing, chem­i­cal dye­ing would be the major con­trib­u­tor to grey water foot­print.

The water con­sumed in all these stages is also called Vir­tu­al Water and helps under­stand how glob­al trade has enabled water-scarce coun­tries to import water-inten­sive goods and prod­ucts from oth­er coun­tries. The glob­al fresh­wa­ter with­drawals have been increas­ing mul­ti­fold over the past few decades owing not just to pop­u­la­tion explo­sion, but also due to dietary choic­es, inten­sive agri­cul­ture, indus­tri­al use and high con­sump­tion lifestyle pat­terns.

Water — Food Nexus:

Water is the most fun­da­men­tal input to agri­cul­ture. The largest glob­al fresh­wa­ter with­draw­al is towards grow­ing our food, which accounts for 69% of the total fresh­wa­ter with­drawals. This includes both rain-fed as well as pumped irri­ga­tion for agri­cul­ture. Accord­ing to the FAO, 60% more food will need to be pro­duced to meet the needs of the grow­ing pop­u­la­tion by 2050, along with bal­anc­ing nutri­tion­al require­ments and accom­mo­dat­ing dietary pref­er­ences. With chron­ic water short­age already a man­i­fes­ta­tion in many parts of the world, sus­tain­able use of water, espe­cial­ly in the agri­cul­ture sec­tor is of high pri­or­i­ty.

Drip irri­ga­tion, regen­er­a­tive agri­cul­tur­al prac­tices, per­ma­cul­ture, pre­ci­sion farm­ing and even prac­tices like mulching and com­post­ing increase the water reten­tion capac­i­ty of the soil, and go a long way in reduc­ing the amount of water con­sumed in the grow­ing of food. Crop diver­si­fi­ca­tion and cul­ti­va­tion of less water con­sum­ing food grains like mil­lets can reduce water con­sump­tion. Most crops that have low water needs are also cli­mate change resilient, mak­ing it a good strat­e­gy for cli­mate change adap­ta­tion in the food sec­tor.

In the con­text of the water require­ment of food, it is inter­est­ing to note the stark vari­a­tion in water con­sumed by veg­e­tar­i­an and meat-based foods:

1 kg Beef, for exam­ple, requires up to 15,000 liters of water

1 kg of toma­toes, on the oth­er hand, requires less than 300 liters

In addi­tion to its dis­pro­por­tion­ate­ly large water foot­print which is also due to the embed­ded water foot­print of its feed, anoth­er much-debat­ed issue is, low-income coun­tries from the African regions sell­ing their food grains to feed live­stock in the USA and oth­er devel­oped coun­tries, when their own coun­try is bat­tling hunger and mal­nu­tri­tion.

The water foot­print of pack­aged and processed foods is mul­ti­fold the water foot­print of food grains:

  1. An apple takes about 70 liters of water to grow

  2. One glass of processed apple juice would have con­sumed at least thrice as much at 190 liters through its entire process of man­u­fac­tur­ing

  3. So, yes. Our food choic­es, do have a huge impact on the envi­ron­ment. Includ­ing mil­lets in one’s diet & elim­i­nat­ing or at least reduc­ing one’s meat intake — are some sim­ple steps to reduce water foot­print by chang­ing per­son­al con­sump­tion pat­terns.

Food — Ener­gy Nexus:

At almost every step along the agri-food chain, ener­gy is con­sumed, mak­ing food pro­duc­tion, one of the largest con­sumers of elec­tric­i­ty. Ener­gy is required to pump water for irri­ga­tion, pro­duce fer­til­iz­ers and pes­ti­cides, har­vest crops, trans­port, dis­trib­ute, store food, and impor­tant­ly, in food pro­cess­ing. In 2011, the FAO released an issue paper titled “ENERGY-SMART” FOOD FOR PEOPLE AND CLIMATE” in which the high depen­den­cy of the food sec­tor on fos­sil fuels is addressed and strate­gies for decou­pling them is dis­cussed. Ener­gy affects food prices as well as food secu­ri­ty as poor farm­ers are most vul­ner­a­ble to changes in the prices of oil, gas, and car­bon. Glob­al food sup­ply and con­sump­tion take one-third of the total end-use ener­gy, mak­ing food waste anoth­er major con­trib­u­tor to ener­gy waste as glob­al­ly, over one-third of the food that is pro­duced, is wast­ed.

There is oppor­tu­ni­ty aplen­ty at every step in the agri­food chain to increase ener­gy effi­cien­cy and reduce ener­gy con­sump­tion. For exam­ple, NPK and Potash blend­ed fer­til­iz­ers have very high embed­ded ener­gy dur­ing man­u­fac­ture (in addi­tion to being high­ly pol­lut­ing). Replac­ing them with local com­post, manures & grow­ing legu­mi­nous plants can reduce ener­gy inputs in the form of fer­til­iz­ers as well as save ener­gy spent on trans­port­ing it to the farm. Pro­cess­ing of food requires ener­gy for heat­ing, cool­ing, pack­ag­ing, and cold stor­age. This report that explores poten­tial low-car­bon paths in agri­food chains states that “the ener­gy need­ed for ‘beyond the farm gate’ oper­a­tions glob­al­ly totals around three times the ener­gy used ‘behind the farm gate’ ” , which is, to grow the food. Small scale renew­able ener­gy based setups behind the far­m­gate, or local­ly, say for dry­ing and cold stor­age can sig­nif­i­cant­ly reduce post har­vest loss (and ener­gy wastage), but also increase farmer incomes.

Ener­gy and water inputs at dif­fer­ent stages of select­ed veg­etable val­ue chains

The gen­er­a­tion of ener­gy from agri­cul­tur­al waste, bio­mass, and food pro­cess­ing plants can be used for decen­tral­ized on-site pro­duc­tion of elec­tric­i­ty and heat. Renew­able ener­gy sources such as wind, solar and hydro are gen­er­al­ly avail­able on most farm­lands. Bio­mass has the poten­tial for local renew­able ener­gy gen­er­a­tion and can bring co-ben­e­fits to stake­hold­ers in rur­al com­mu­ni­ties. Direct gen­er­a­tion of ener­gy from food crops how­ev­er also draws crit­i­cism, giv­en the glob­al hunger sce­nario and debates on using crops for food ver­sus fuel arise.

Con­sum­ing local­ly grown foods, avoid­ing pack­aged and processed foods are some sim­ple steps to reduce your ener­gy foot­print of per­son­al food con­sump­tion.

Energy — Water Relation

Water and ener­gy sys­tems are inex­tri­ca­bly depen­dent on each oth­er. Water is essen­tial for dif­fer­ent stages of pow­er gen­er­a­tion, with pow­er gen­er­a­tion account­ing for 44% of total glob­al water with­drawals. The vol­ume of water con­sumed per unit of elec­tric­i­ty gen­er­a­tion depends on the source. About 80% of glob­al ener­gy pro­duc­tion still comes from fos­sil fuels such as coal, nat­ur­al gas, and oil, which is a very water thirsty affair. The heat ener­gy used to burn fos­sil fuels is then used in the ther­mal pow­er sta­tions to con­vert water into high-pres­sure steam for dri­ving tur­bines. The steam is then cooled and con­densed into water before being reheat­ed to dri­ve the tur­bines again. The process of cool­ing also required huge amounts of water at a low­er tem­per­a­ture to pass through in exchang­ers. In pow­er gen­er­a­tion, the water with­drawn from adja­cent water bod­ies, is to be sent back to the water bod­ies after pass­ing through the var­i­ous com­po­nents for pow­er gen­er­a­tion, with­out chang­ing its phys­i­cal or chem­i­cal qual­i­ties, that may adverse­ly affect aquat­ic life. For exam­ple, send­ing the with­drawn water back at high­er tem­per­a­ture caus­es ther­mal pol­lu­tion and caus­es seri­ous eco­log­i­cal imbal­ance by dis­rupt­ing the sen­si­tive aquat­ic life. Water con­sumed in elec­tric­i­ty gen­er­a­tion, is the water that is lost due to evap­o­ra­tion. Fos­sil fuel plants require humon­gous amounts of water for cool­ing in addi­tion to the water already used for extrac­tion, min­ing, pro­cess­ing, refin­ing and dis­pos­al of fos­sil-fuel residues.

Hydropow­er plants again, only ‘with­draw’ water to rotate their tur­bines. Renew­able ener­gy sources such as solar and wind not just reduce green­house gas­es, but also water con­sump­tion dur­ing oper­a­tion. The water sec­tor con­sumes ener­gy for pur­pos­es such as water treat­ment, pump­ing, and desali­na­tion.


Com­part­men­tal­ized deal­ing by dif­fer­ent depart­ments and min­istries of coun­tries has in the past led to con­flict­ing poli­cies and strate­gies with­in the intrin­si­cal­ly linked Food-Water-Ener­gy space. Heavy sub­sidy on elec­tric­i­ty for pump­ing water and free pow­er sup­ply for agri­cul­ture, has led to over­ex­ploita­tion of ground­wa­ter resources by pro­mot­ing waste­ful use of water and cul­ti­va­tion of water-inten­sive crops in many parts of India. This is one exam­ple of threat­en­ing long term water secu­ri­ty while striv­ing to achieve food secu­ri­ty. To build syn­er­gies across dif­fer­ent sec­tors and achieve food, water, and ener­gy secu­ri­ty, there is a need for coher­ent gov­er­nance struc­tures and inte­grat­ed man­age­ment based on the Nexus approach.


[1] “The Water-Ener­gy-Food Nexus: A new approach in sup­port of food secu­ri­ty and sus­tain­able agri­cul­ture” (PDF). Food and Agri­cul­ture Orga­ni­za­tion of the Unit­ed Nations. 2014. Retrieved 2019-02-07.

[2] Mekon­nen, Mes­fin M., P. W. Ger­bens-Leenes, and Arjen Y. Hoek­stra. “The con­sump­tive water foot­print of elec­tric­i­ty and heat: a glob­al assess­ment.” Envi­ron­men­tal Sci­ence: Water Research & Tech­nol­o­gy 1.3 (2015): 285–297.

[3] Water-Food-Ener­gy Nexus in India

[6] Oppor­tu­ni­ties For Agri-Food Chains To Become Ener­gy-Smart :‑i5125e.pdf

[7] Water-Ener­gy-Agri­cul­ture Nexus in Pun­jab: An Inte­grat­ed Mod­el­ing Approach


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