1.
CCAFS/4.1000 webinar
April 22, 2020
Akiko Nagano, Environment Policy Office, MAFF
Soil Carbon Sequestration in the
Nationally Determined Contributions
Japan’s case
0

2.
Outline
1. Background
➢Greenhouse gasses emissions in Japan
2. Questions from the organizer
➢How was soil organic carbon assessed in
the NDC process?
➢Why?
➢Lessons to other countries
1

3.
Total emissions in entire
Japan in FY2017
1,292 million t-CO2
N2O from agricultural soil
5.41million t-CO2（10.5％）
CO2 from fuel
burning
18.29 million
t-CO2（35.5 ％）
CH4 from livestock
excrement management
2.32 million t-CO2（4.5％）
Total emissions in the agricultural,
forestry and fishery industries in
FY2017
51.54 million t-CO2
CH4
（45.2%）
CO2
（36.6 %）
N2O
（18.2 %）
CO2
18.84 million
t-CO2（1.5％）
CH4
23.31 million
t-CO2（1.8％）
Emissions in the agricultural,
forestry and fishery industries
51.54 million t-CO2 (4.0%)
N2O from
livestock
excrement
management
3.92 million t-CO2
（7.6％）
１．Greenhouse gas emissions in Japan
Source: Greenhouse Gas Inventory Office of Japan
CH4 from enteric
fermentation of
livestock
7.28 million t-
CO2（14.1％）
CH4 associated with
rice cultivation
13.63 million t-CO2
（26.4％）
N2O
9.39 million
t-CO2
（0.7％）
2

4.
How was SOC assessed in the NDC process?
Why this approach?
1. Science
➢Long-term monitoring
➢Models at tier 3 level
Modified Roth-C for SOC and DNDC-rice for methane
2. Policy
➢ National Plan for Global Warming Countermeasures
Mid-term target for 2030, and progress assessed yearly
3
Because soils have been considered fundamentally
important for agriculture!

5.
Stationary
Monitoring Points
Soil carbon in agricultural soil
Soil Carbon
Stock Map
(1) Long-term monitoring of agricultural soil
◼ A national program since 1979
◼ Sampling at about 4000 - 20,000 sites
(2) Calculation models for soil organic C and GHG emission
◼ Change of soil carbon stock in cropland: Modified RothC Model
◼ Methane emissions from rice cultivation: DNDC-Rice Model
◼ Application of IPCC Tier 3 approach to Japanese National GHG
Inventory Report from 2015
◼ Physico-chemical properties
◼ Soil management record by
questionnaires
4

6.
What are the lessons based on Japan’s experience?
Science-based quantification!
1. Models are useful tools.
2. Long-term monitoring should not be undermined.
3. Need to look at the total global warming potential
(GWP) because practice for increasing soil carbon
may have trade-offs (increase CH4 and/or N2O).
5
For more
➢ Submission of Japan’s NDC (March 30, 2020)
https://www.env.go.jp/en/headline/2442.html
➢ International symposium “Agriculture is the solution! for climate
change” (May, 2019) https://www.maff.go.jp/e/policies/env/agsol.html
➢ International symposium for scaling up and out of climate-smart
technologies and practices for sustainable agriculture (Nov, 2019)
http://www.maff.go.jp/j/kanbo/kankyo/seisaku/kikouhendou/symposium/cs.html