The document discusses emerging technologies and solutions for mitigating agricultural greenhouse gas emissions, noting that while increasing productivity through best practices can help, more is needed to meet global goals, and recommends further developing technologies like nitrification inhibitors, low-methane feeds and breeding, as well as addressing challenges to adoption, measurement, and building capacity.
Emerging technologies and best practices for agricultural methane mitigation
1. The future of mitigation:
new technologies and emerging solutions
Hayden Montgomery
Special Representative
6 October 2019
2.
3. IPCC SR: Global Warming of 1.5 Degrees
Agriculture CH4
-11% to -30% by 2030
-24% to -47% by 2050
Agriculture N2O
+3% to -21% by 2030
+1% to -26% by 2050
4. Business as usual insufficient
Sustainable increases in yield: per animal, per hectare, per day, per unit of input, can lead to significant reductions in
emissions per unit of milk, meat and crop, however this alone will be insufficient to meet global goals.
,
5. Beyond business as usual
• We need wide-spread adoption of best practices management, e.g:
improved animal feeding, breeding and selection, and health to increase overall
productivity in the system;
maximizing grain yield – strong negative correlation between yield and emission intensity for rice,
wheat and maize means emission intensity can be reduced while farmers' yields increase;
optimizing type, rate, time and placement of nitrogen fertilizer application;
fully exploit variability within and between systems (management explains a lot);
improved genetics for increased yield and/or resistance to climate impacts, e.g. drought
• There are already good reasons to do these things – strong links to improved resilience, livelihoods,
food security, economic development – yet there remain large gaps in adoption.
• Much more is needed and there aren’t always obvious co-benefits as above – huge challenge.
7. Livestock: 30% reductions would be possible by 2030…
…by shifting all producers within a system and region to top 25% of producers within same system and region
8.
9. USEFUL TECHNOLOGIES FOR MITIGATION OF AND
ADAPTATION
USEFUL TECHNOLOGIES FOR MITIGATION OF AND ADAPTATIONBest Practice
10. USEFUL TECHNOLOGIES FOR MITIGATION OF AND ADAPTATIONBest practice (almost): AWD rice
Better root development
Irrigation water savings
Reduced arsenic uptake
Higher or similar yields
Better nutrient availability
AWD is a management practice in irrigated lowland rice that saves
water and reduces GHG emissions while maintaining yields.
• Reduce water use
• Greenhouse gas mitigation potential.
48% compared to continuous flooding.
Flooded Non-Flooded
It is defined by the periodic drying and re-flooding of the rice field.
Reduced lodging
Reduced damage due to fungal diseases
Higher resistance to certain pests
Better soil conditions for machine operation
Reduction in mosquito-borne diseases
AWD CO- BENEFITS:
BENEFITS:
Alternate
Wetting and
Drying
11. Emerging solutions: breeding low CH4 sheep
Breeding: selection of low CH4 emitters
Sheep selected for
divergent CH4 yield on
lucerne pellets also
express the same trait
when fed fresh pasture
Repeatability
n records Mean h2 ± s.e. Across days Across rounds
CH4 (g/d) 5236 24.6 0.29 ± 0.05 0.94 ± 0.003 0.55 ± 0.02
CH4 (g/kg DMI) 5235 15.7 0.13 ± 0.03 0.89 ± 0.005 0.26 ± 0.02
Heritability (h2) and repeatability estimates for methane traits in sheep
Pinares-Patiño et al. 2013
12. Emerging solutions: enteric CH4 inhibitors
Predict compounds that
could inhibit essential
methanogen enzymes
Leading compounds showing >30% reduction consistently,
sometimes much higher
Identify compounds that
inhibit essential methanogen
enzymes
13. Emerging solutions: nitrification inhibitors
• Proven and commercially available with more than
>70% reductions in N2O/nitrate leaching, e.g. DCD,
but regulatory hurdles
• Other new leading compounds up to 90% reduction
in N2O, but must first be registered, commercialised
14. (Almost) emerging solutions: low methane feeds
• Brassicas
• Forage rape reduces CH4 emission by 20-30% in sheep (limited cattle studies)
• Linear response to dietary inclusion
• Fodder beet (reductions in CH4 observed when > 75% of the diet)
• High cereal diets (>80% of total diet)
• Lipid supplements (variable response)
• Maize silage (inconsistent response)
• Plants with tannins (depends on dose and type of tannin)
15. Some proof of concept priorities
Selecting for low
emissions cattle
BNI and other
plant effects on
nitrogen cycle and
N20 emissions
Selecting for low
emissions rice
cultivars
16. Some proof of concept priorities
Breeding CH4
inhibiting grasses,
e.g. high lipids
Enteric CH4
vaccine
Biological delivery
of inhibitory
compounds
17. Assessing mitigation potential – prioritizing research investment
• Readiness
stage of technological development
• Potential impact
Efficacy of intervention
Proportion of emissions targeted
• Potential for adoption
“in the seed” vs management practice or system
change
Cost
Other benefits
18. Getting technology to market, e.g. of enteric methane mitigation compound
Methane mitigation
compound
Non- toxic?
Consistent
effect?
Durable effect?
• Measuring the ‘right’
component in feeds
• Empirical evidence
required
• Fundamental
understanding of
variation
• Better measurement
methods
• Reliable data and
better models for
systems and value
chains
• Fits with systems?
• Effects along value
chain?
• Farmers’ drivers:
Profitability
(cost:benefit of
interventions)
Productivity
Better feeds
Reliable feed sources
Incentives
Taxes
• Societal needs
Environmental protection
• Market trends
• Adoption by farmers
19. Making mitigation count - MRV
• Complexity of emissions:
Product of microbiological processes in sol, plant, animal
Vary significantly in time and space
Certainty of outcome?
• Methodological considerations:
IPCC categories vs. economic sector
Inventory approach vs LCA – pollution swapping?
Other, e.g. impact of updating GWP values or other metrics on
emissions trends and absolute levels
• Activity data:
Largest source of uncertainty
Chioce of mitigation technology will have different activity data
implications, e.g. vaccine, inhibitor, management
How to fill gaps?
20. Scarcity of capability and capacity in many parts of the world
• Need to develop pipeline of next generation of science leaders (Masters, PhD, Post-Docs).
Significant quantification challenge remains
• Emissions vary significantly in time and space
• Five of 140 developing countries can routinely capture livestock GHGs in national inventories
• Five of 22 mitigation actions able to be captured in inventories in EU countries
Sustained, long-term investment in science is needed
• To retain human capability and research infrastructure
• At a scale proportional to the scale of the challenge
• In a way that facilitates collaboration
Climate change impacts will make mitigation even more difficult
• Harder to retain carbon in soil
• Reduce quality of crops and forages
• Reduce productivity and yields in already vulnerable regions
Challenges significant