How much greenhouse gases are emitted by agriculture?

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.

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.

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.

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.

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.

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.