Nexus Thinking

camps
Mike Bing/Flickr

O el que ve a ser el mateix, Aigua-Agricultura-Energia. De fet, el 70% del consum mundial d’aigua se l’emporta la producció agrícola, usada al llarg de tota la cadena agroalimentària, així com també  s’utilitza per al transport i producció d’energia.

D’altra banda, la producció d’aliments i la seva logística generen una despesa del 30% de l’energia consumida a nivell global. També necessitem energia per a extreure, bombejar, emmagatzemar, transportar i tractar l’aigua…

D’aquesta manera, queda clar el nexe del títol, proposat per la FAO de cara a afrontar un dels reptes més importants del segle XXI:

“Cities, industry and other users, too, claim increasingly more water, energy and land resources, and at the same time, face problems of environmental degradation and in some cases, resources scarcity. This situation is expected to be exacerbated in the near future as 60 percent more food will need to be produced in order to feed the world population in 2050. Global energy consumption is projected to grow by up to 50 percent by 2035 (IEA 2010). Total global water withdrawals for irrigation are projected to increase by 10 percent by 2050 (FAO 2011a).”

nexus-thinking
Font: www.waternexussolutions.org

La combinació de ciència i tecnologia, així com el canvis de comportament vers el consum (per exemple, gestionant-ne la demanda abans que començar a planificar noves fonts de suministre) seran clau de cara a l’equilibri entre els tres elements.

En aquest sentit, i pel què fa a la gestió de la demanda de l’aigua, Robert C. Brears, autor de Urban Water Security proposa els següents punts en un article recent:

  • Reducció de les pèrdues i el mal ús.
  • Optimització de l’ús de l’aigua aprofitant sinergies entre diferents usuaris al llarg dels cursos fluvials.
  • Promoure un major estalvi, tant financer com d’infrastructures.
  • Reducció de l’estrès hídric reduint-ne els nivells de consum insostenibles.
  • Minimitzar la degradació de la qualitat de l’aigua.

Són punts molt generalistes però immediatament després en descriu dos exemples:

Tariff simulator in Portugal

“The Alqueva Multi-purpose Undertaking (EFMA) in the south of Portugal is Europe’s largest irrigation project. Around 120,000 hectares of irrigation area has been set up in a region where soils are highly suitable for irrigation and the number of hours of sunshine is above the European average. As part of EFMA, irrigators are offered a tool for simulating water consumption and estimating its cost. The irrigation tariff simulator calculates the cost of water consumption based on the location and type of supply, year of introduction of the crop, amount of crop expected and the area covered.”

Water quality trading in the Ohio River Basin

The Ohio River Basin Water Quality Trading Pilot Project is a first-of-its-kind interstate program that spans Ohio, Indiana and Kentucky to evaluate the use of trading by industries, utilities, farmers and others to meet water quality goals while minimizing costs. The water quality trading program, a market-based approach to achieving water quality goals, allows permitted discharges to generate or purchase pollution reduction credits from another source. The premise of the water quality trading program is that:

  1. Facility A, for example, a wastewater treatment plant, needs to meet nutrient limits for its water quality permit and therefore water quality trading is one option
  2. To reduce nutrients in the watershed, Facility A pays Farmer B to do a variety of things, for instance, reduce fertilizer user, plant stream side buffers with trees or keep livestock manure from getting into the waterways, with each conservation practice verified
  3. Nutrient reductions are quantified as credits, for example, equal to one pound of nutrient reduction. Credits are then reviewed and approved by a regulatory agency
  4. Facility A can then use those credits to meet permit requirements.

Aques són només dues de moltes de les iniciatives (vegeu també els water markets australians) encarades a la gestió de la demanda d’aigua. Un camí de llarg recorregut dins del nou paradigma del segle XXI, el Nexus Thinking.

 

Complementa-ho:

· The Water-Energy-Food Nexus (Document de la FAO)

· Reducing Water-Food Nexus Pressures (Robert C. Brears)

· Can ‘nexus thinking’ alleviate global water, food and energy pressures? (The Guardian)

· Considering the energy, water and food nexus: Towards an integrated modelling approach (Energy Policy. September 2011)