Ọtụtụ puku nri

Ụgbọ nri bụ ebe a n'ebu nri site n'oge a n'eme ya rụo mgbe ọ ruru onye n'azụ ya. Ụzọ nri bụ otu ihe eji eme ihe mgbe a n'anwale mmetụta gburugburu ebe obibi nke nri, dị ka akara carbon nke nri.

Echiche nke nri kilomita malitere na mbido afọ 1990 na mba United Kingdom. Ọ bụ Prọfesọ Tim Lang http://www.city.ac.uk/communityandhealth/phpcfp/foodpolicy/index.html.  He explains its history in this article Tim Lang (2006). 'locale / global (food miles)', Slow Food (Bra, Cuneo Italy), 19, May 2006, pp. 94–97 na Sustainable Agriculture Food and Environment (SAFE) Alliance The SAFE Alliance merged with the National Food Alliance in 1999 to become Sustain: the alliance for better food and farming http://www.sustainweb.org/. Professor Tim Lang chaired Sustain from 1999 to 2005. chepụtara ya ma gosipụta ya na mbụ na akụkọ, "The Food Miles Report: The Dangers of Long-Distance Food Transport", nke Angela Paxton nyochara ma dee.Paxton, A (1994). "The Food Miles Report: The Dangers of Long-Distance Food Transport". SAFE Alliance, London, UK. https://www.sustainweb.org/publications/the_food_miles_report/Iles, A. (2005). "Learning in sustainable agriculture: Food miles and missing objects". Environmental Values, 14, 163–83

Ụfọdụ ndị ọkà mmụta kwenyere na mmụba nke njem nri dị anya bụ n'ihi ijikọ azụmahịa zuru ụwa ọnụ; n'elekwasị anya na ebe a n'enye nri n'ime obere, nnukwu mpaghara; mgbanwe dị egwu na usoro nnyefe; mmụba na nri a n'edozi na nke a n'etinye na ngwugwu; na ime obere njem na nnukwu ụlọ ahịa. Ndị a n'eme obere akụkụ nke gas n'ekpo ọkụ nke nri n'emepụta; 83% nke ikuku CO2 n'ozuzu ya nọ n'oge mmepụta.

Ọtụtụ nnyocha na-atụle ikuku n'esi n'ime usoro nri dum, gụnyere mmepụta, oriri, na njem. Ihe ndị a gụnyere atụmatụ nke ikuku n'emetụta nri nke gas n'ekpo ọkụ 'ruo ọnụ ụzọ ugbo' na 'n'elu ọnụ ụzọ ugwo'. Na mba UK, dịka ọmụmaatụ, ikuku n'emetụta ọrụ ugbo nwere ike ịbụ ihe dịka 40% nke Usoro nri n'ozuzu ya (gụnyere mkpọsa, nkwakọ ngwa ahịa, mmepụta fatịlaịza, na ihe ndị ọzọ), ebe gas n'ekpo ọkụ n'apụta na njem n'akpata ihe dị ka 12% nke ikuku nri n'ogologo.Garnett 2011, Food Policy

Nnyocha e mere n'afọ  n'atụ aro na nri zuru ụwa ọnụ CO n'esi n'iyi bụ okpukpu 3.5-7.5 karịa ka e mere atụmatụ na mbụ, na njem n'eme ihe dị ka 19% nke ngụkọta nri,   ọ bụ ezie na ịkwaga na nri sitere na osisi ka dị mkpa. 

A katọrọ echiche nke "ụgbọ nri", ọ bụghịkwa mgbe niile ka a n'ejikọta kilomita nri na mmetụta gburugburu ebe obibi nke mmepụta nri. N'iji ya tụnyere, pasentị nke ike niile eji eme nri n'ụlọ bụ 26% na nhazi nri bụ 29%, karịa njem.John Hendrickson, "Energy use in the U.S. Food System: A summary of existing research and analysis." Sustainable Farming (Ste. Anne de Bellevue, Quebec), vol. 7, no. 4. Fall 1997.

With processed foods that are made of many different ingredients, it is very complicated, though not impossible, to calculate the  emissions from transport by multiplying the distance travelled of each ingredient, by the carbon intensity of the mode of transport (air, road or rail). However, as both Tim Lang and the original Food Miles report noted, the resulting number, although interesting, cannot give the whole picture of how sustainable – or not – a food product is.