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Agriculture: can we lower emissions whilst feeding the world?

How much greenhouse gases are emitted by agriculture?

Anaïs Marechal, science journalist
On February 23rd, 2022 |
3 mins reading time
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How much greenhouse gases are emitted by agriculture?
Véronique Bellon
Véronique Bellon
Director of Institut convergences agriculture numérique
Key takeaways
  • Worldwide, the agricultural sector is responsible for 23% of anthropogenic greenhouse gas (GHG) emissions – a sum of 12 GtCO2 equivalent/year.
  • Reduction of GHG emissions, carbon storage in soil and energy production are criteria that could be targeted by the agricultural sector. In France, this would lead to a 46% reduction in greenhouse gas emissions from agriculture by 2050.
  • Technology is not the solution, but it is part of it. It can help detect problems early: optical sensors for plant health, connected insect traps to detect pests, or sensors that detect animal movement to monitor their health.
  • While, until now, digital technologies have focused on economic gains and comfort, which are the main concerns of farmers, their contribution and impact on climate change are now becoming increasingly important.

In a rapid­ly chang­ing world, the pri­or­i­ty for the agri­cul­tur­al sec­tor is to feed more peo­ple. At the same time, the sec­tor is trans­form­ing itself by adapt­ing to cli­mate change, or even mit­i­gat­ing it, through a vari­ety of dif­fer­ent mea­sures: the reduc­tion of green­house gas (GHG) emis­sions, the stor­age of car­bon in soil and ener­gy pro­duc­tion. In France, the imple­men­ta­tion of all these mea­sures – pro­mot­ed by the Nation­al Low Car­bon Strat­e­gy – would lead to a 46% reduc­tion in green­house gas emis­sions linked to agri­cul­ture by 20501.

On a glob­al lev­el the “agri­cul­ture, forestry and oth­er land use” sec­tor is respon­si­ble for 23% of anthro­pogenic GHG emis­sions, i.e. 12 GtCO2 equivalent/year2. Most of these emis­sions are due to either agri­cul­tur­al emis­sions of methane (CH4) (4 GtCO2 equivalent/year) and nitrous oxide (N2O) from nitro­gen fer­til­i­sa­tion (2.2 GtCO2 equivalent/year), or to land use changes and defor­esta­tion, which release 5.2 Gt of car­bon diox­ide (CO2) per year.

How can new technologies help the agricultural sector to reduce its GHG emissions?

Accord­ing to a Euro­pean Com­mis­sion report3, pre­ci­sion farm­ing could reduce GHG emis­sions from Euro­pean agri­cul­ture by 1.5 to 2%. This is main­ly based on vari­able rate appli­ca­tion sys­tems, which deliv­er a dose of fer­tilis­er adapt­ed to the needs of the plants, thus reduc­ing the asso­ci­at­ed N2O emis­sions. Oth­er tools that can reduce GHG emis­sions are self-guid­ance devices for agri­cul­tur­al machin­ery, through improved dri­ving that reduces fuel consumption.

Pre­ci­sion farm­ing allows for indi­vid­u­alised inputs to a plant or ani­mal accord­ing to its needs. It is based on an “observation/diagnosis/prediction/action” cycle that relies on infor­ma­tion and com­mu­ni­ca­tion tech­nolo­gies. Satel­lite data, increas­ing­ly sup­ple­ment­ed by on-board sen­sors, are used to mea­sure plant defi­cien­cies, par­tic­u­lar­ly in field crops. This data is then inte­grat­ed into agro­nom­ic mod­els that pro­vide rec­om­men­da­tions for fer­tilis­er appli­ca­tions at vari­able rates, depend­ing on the posi­tion with­in the plot. Sim­i­lar deci­sion sup­port tools are also used in live­stock farm­ing to avoid over­feed­ing cat­tle, lim­it­ing manure and thus CH4 emis­sions.

Are these tools used by producers?

Dig­i­tal tech­nol­o­gy suf­fers from a sig­nif­i­cant lack of use. In Europe, as lit­tle as 22% of farms use vari­able rate fer­tilis­er appli­ca­tion tools. In France, only 10% of cere­al farms have adopt­ed them.

Sev­er­al fac­tors explain this. First­ly, the return on invest­ment is not always clear­ly eval­u­at­ed. These tech­nolo­gies and ser­vices are cost­ly, and farm­ers need to know the ben­e­fits – whether eco­nom­ic, envi­ron­men­tal, or relat­ed to per­ceived use­ful­ness. In the Occ­i­tanie region, we have set up the Occ­i­tanum Liv­ing Lab to test these tools on dif­fer­ent farms and eval­u­ate the ben­e­fits and costs they entail.

The use­ful­ness of this tool depends on how it is inte­grat­ed into the work­ing envi­ron­ment. This is why it is impor­tant to encour­age co-design that brings togeth­er man­u­fac­tur­ers and farm­ers to pro­duce tools that are adapt­ed to farm­ers’ needs. They can thus be sim­pler to use and adapt­ed to the work car­ried out in the field. How­ev­er, there are still a num­ber of obsta­cles: lack of train­ing in the agri­cul­tur­al sec­tor in gen­er­al, ide­o­log­i­cal oppo­si­tion, ques­tions about data secu­ri­ty, etc.

Is technology enough for an ecological transition?

No, tech­nol­o­gy is not the solu­tion, but it is a part of it. Rather, it is the changes in agri­cul­tur­al prac­tices, which tech­nol­o­gy will facil­i­tate, that reduce the impact on the envi­ron­ment. Tech­nol­o­gy accom­pa­nies these changes, to help them devel­op on a larg­er scale, for example.

What change(s) in farming practices are you thinking of?

I am talk­ing about agroe­col­o­gy. This approach con­sists of pro­mot­ing a bal­ance in the sys­tem with the help of eco­log­i­cal process­es, with­out chem­i­cal inputs, unlike con­ven­tion­al agri­cul­ture. For exam­ple, mono­cul­tures can be replaced by a mix­ture of species, which reduces the need for inputs.

But agroe­col­o­gy is a more com­plex farm­ing sys­tem. On the one hand, it requires close atten­tion to plant and ani­mal health to antic­i­pate and treat the prob­lem quick­ly. Tech­no­log­i­cal tools can help to detect prob­lems ear­ly: opti­cal sen­sors for plant health, con­nect­ed insect traps to detect pests, or ani­mal move­ment sen­sors to mon­i­tor their health. On the oth­er hand, mix­ing plant species requires pre­ci­sion sow­ing, even in the mid­dle of a pre­vi­ous crop. Pre­ci­sion seed­ers make it eas­i­er to do this, while avoid­ing turn­ing over the soil and releas­ing CO2 into the atmosphere.

Satellite images, sensors, data… Don’t these tools also have an environmental footprint?

This is a ques­tion that the sci­en­tif­ic com­mu­ni­ty is begin­ning to address, but an assess­ment of their envi­ron­men­tal foot­print through life cycle analy­sis has not yet been made. Even so, the GHG sav­ings from dig­i­tal tools are expect­ed to be much high­er than their actu­al eco­log­i­cal foot­print.  Nev­er­the­less, we must con­tin­ue to take mea­sure­ments in order to get an accu­rate pic­ture of the envi­ron­men­tal benefits.

The cen­tral issue is data flow. We are not yet at the stage of big data in agri­cul­ture, but the ques­tion needs to be asked before the data explodes. We will need to con­sid­er the choice of data to be kept, the form of data stor­age, devel­op­ment of fru­gal algorithms…

While until now dig­i­tal tech­nolo­gies have main­ly been con­cerned with eco­nom­ic gains and com­fort, which are the main con­cerns of oper­a­tors, their con­tri­bu­tion to and impact on cli­mate change are now becom­ing increas­ing­ly important.

1Les enjeux cli­mat pour le secteur agri­cole et agroal­i­men­taire en France, Car­bone 4, mai 2021
2IPCC, 2019: Sum­ma­ry for Pol­i­cy­mak­ers. In: Cli­mate Change and Land: an IPCC spe­cial report on cli­mate change, deser­ti­fi­ca­tion, land degra­da­tion, sus­tain­able land man­age­ment, food secu­ri­ty, and green­house gas flux­es in ter­res­tri­al ecosys­tems [P.R. Shuk­la, J. Skea, E. Cal­vo Buen­dia, V. Mas­son-Del­motte, H.- O. Pört­ner, D. C. Roberts, P. Zhai, R. Slade, S. Con­nors, R. van Diemen, M. Fer­rat, E. Haugh­ey, S. Luz, S. Neo­gi, M. Pathak, J. Pet­zold, J. Por­tu­gal Pereira, P. Vyas, E. Hunt­ley, K. Kissick, M. Belka­ce­mi, J. Mal­ley, (eds.)]. In press
3Soto, I., Barnes, A., Bal­afoutis, A., Beck, B., Sanchez, B., Vangeyte, J., Foun­tas, S., Van der Wal, T., Eory, V., Gómez-Bar­bero, M., The con­tri­bu­tion of Pre­ci­sion Agri­cul­ture Tech­nolo­gies to farm pro­duc­tiv­i­ty and the mit­i­ga­tion of green­house gas emis­sions in the EU, EUR (where avail­able), Pub­li­ca­tions Office of the Euro­pean Union, Lux­em­bourg, 2019, ISBN 978–92-79–92834‑5, doi:10.2760/016263, JRC112505