Report on Research and Development in Agriculture, Forestry and Fisheries No.23 (2007)

Agriculture, Forestry and Fisheries Research Council
Ministry of Agriculture, Forestry and Fisheries, JAPANImpact of Global Warming on Agriculture, Forestry and Fisheries
and Possible Countermeasures in Japan

Summary: Impact of Global Warming on Agriculture, Forestry and Fisheries andPossible Countermeasures in Japan
1. Potential Impact of Global Warming on Agriculture, Forestry and Fisheries
1) Based on a scenario where the temperature rises by an average of 3°C by the 2060s:●The paddy rice yield increases in Hokkaido and decreases in sub-Tohoku region.
●The areas suitable for growing apples gradually move toward the north; the whole of Hokkaido becomes
suitable for growing apples, whereas they no longer grow in the sub-Kanto region.
●The areas suitable for growing Satsuma mandarins extend from the southwest coastal region to the southern
Tohoku coastal region.
●Chicken production dramatically decreases in western Japan, with some areas showing more than a 15%
decrease.
2) Based on a scenario where the temperature rises by an average of 3°C and 5°C by 2081 to 2100, beech
habitats decrease 60% and 90%, respectively, from the current level.
3) Saury fishing off the coast of the Nemuro Peninsula, located in eastern Hokkaido, declines; sauries will bescarce in the seas around Japan about 100 years from now due to increased water temperature.
2. Adaptation to Global Warming1) Paddy rice
●The occurrence of white immature kernels due to high temperatures during the ripening period can beprevented through late planting and direct sowing.
●The Nikomaru variety is recommended because of its good appearance and low occurrence of white
immature kernels.
2) Fruit●Abnormal coloration of grapes due to high temperatures can be prevented by girdling.
●The Ishiji and Tamami varieties are recommended because of the low occurrence of rind puffing, which is
caused by high temperatures during the ripening period.
3. Global Warming Mitigation
1) Methane, a global warming gas, originating from paddy fields can be significantly reduced through midseason
drainage and alternate wetting and drying irrigation, without reducing the rice yield.
2) Carbon sequestration can be maintained and enhanced through proper forest management including that ofmulti-storied forests.

Contents
Preface1

1. Status of Global Warming and Potential Impact

1(1) IPCC Fourth Assessment Report1(2) Observations of climate change at home and abroad

1(3) Global climate change in the future2

2. Impact of Global Warming on Japan’s Agriculture, Forestry and Fisheries

3(1) Real impact of high temperatures on agriculture, forestry and fisheries

3(2) Potential impact of global warming on agriculture, forestry and fisheries

41) Potential impact on agriculture

5a) Paddy rice: Predictions of changes in yields

5b) Fruit: Predictions of changes in areas suitable for growing fruit

6c) Predictions of changes in the production of livestock and grass

6

Column 1 Higher CO2 concentrations could boost agricultural production

72) Forestry: Predictions of a shift in beech habitats

73) Fisheries: Predictions of changes in Pacific saury fishing grounds

8

3. Japan’s Adaptation Technique to Global Warming

8(1) Adaptation technique for white immature and cracked rice grain

8(2) Adaptation technique for abnormal coloration of fruit

9(3) Adaptation technique for freezing damage to wheat and drought damage to soybeans

10(4) Adaptation technique for poor fruit set in eggplants and techniques to cool strawberries

10

4. Japan’s Mitigation Technique to Address Global Warming
Column 2 Enormous amount of carbon is stored in the soil

1111(1) Reduction of greenhouse gas emissions from paddy fields and cattle

11(2) Enhancement of carbon sequestration in forests and wood

12

Column 3 The ocean has huge potential as a carbon sink

13

5. Topics for Future Studies

13Preface

global warming and its potential impact. IPCC is anintergovernmental panel jointly established by the World

The Agriculture, Forestry and Fisheries ResearchCouncil Secretariat, Ministry of Agriculture, Forestry
and Fisheries, Japan (MAFF), prepares and distributes
series of the Report on Research and Development inAgriculture, Forestry and Fisheries for public relations.
This report* reviews “Impact of Global Warmingon Agriculture, Forestry and Fisheries and Possible
Countermeasures in Japan” as particularly high interest
to public.
In fact, global warming is becoming a worldwide
concern because of the IPCC Fourth Assessment
Report**, impact of Al Gore’s “Inconvenient Truth” andthe scorchingly hot summer of 2007 in Japan. ScientificMeteorological Organization (WMO) and the United
Nations Environmental Program (UNEP) in 1988,
tasked with assessing human-induced climate change
and its potential impact and global warming adaptation/
mitigation measures from scientific, technologicaland socioeconomic viewpoints. The first, second andthird reports were released in 1990, 1995 and 2001,
respectively. For the fourth report, Working Group
1 produced a report on the physical science basis in
February, Working Group 2 on impacts, adaptation andvulnerability in April and Working Group 3 on mitigationof climate change in May, followed by an synthesis
report released in November.

research program on global warming supported by
MAFF have focused on development of mitigation(2) Observations of climate change at home andtechnique designed to reduce (or capture) greenhouseabroadAccording to the report of Working Group 1 on thegas emissions originating from agriculture, forestry andfishery sectors. The IPPC Fourth Assessment Report,
meanwhile, concludes that global warming is accelerating
and most of the warming phenomena observed attributes

physical science basis, atmospheric CO2 concentration
had increased from approximately 280 ppm in preindustrial times to 379 ppm in 2005 (a 1.4 times increase

to human activities. As global warming is now inevitable,
Global mean temperature(increased 0.74℃ in 100 years)

efforts should be stepped up to work on development
Deviation (℃)

of adaptation technique. MAFF will thus strategicallydevelop both adaptation and mitigation techniques.
This report, therefore, covers assessments of global
warming impacts in the past and future, and major resultsin adaptation and preventive (mitigation) researches in

YearJapan.
*This report was originally published in Japanese inJapan’s mean temperature(increased 1.07℃ in 100 years)
Deviation (℃)

December 2007.
**IPCC is an acronym for “Intergovernmental Panel on
Climate Change.” (http://www.ipcc.ch/)

1 . S t a t u s o f G l o b a l Wa r m i n g a n d
Potential Impact

Year

Figure 1 Temperature Increase in the World and Japan
Bar graph: Difference between each year’s mean temperatureand the normal temperature (i.e., the mean temperature
between 1971 and 2000)
Blue line: Five-year moving average of the deviation
Red line: Long-term changes(1) IPCC Fourth Assessment Report
The IPCC Fourth Assessment Report, released
in 2007, provides the latest findings on the status of−1−

in about 100 years), resulting in an increase of global

Temperature increases in 2100 based on emission scenariosmean temperature of 0.74°C (see top of Figure 1). The

Emission scenario

AverageRangereport also suggests that the second half of the 20th

A1FI

4.0

2.4~6.4

century was likely the warmest 50-year period in the

A1T

2.4

1.4~3.8

Northern Hemisphere in the last 1300 years, with the

A1B

2.8

1.7~4.4

mean temperature increasing twice as rapidly as in the

A2

3.4

2.0~5.4

B1

1.8

1.1~2.9

B2

2.4

1.4~3.8

global warming is undoubtedly real and almost concludes
that global warming gases produced by human activities
are to blame. These observations are more affirmative
than those in the IPCC Third Assessment Report (2001),
which indicated a temperature increase of 0.6°C overthe last century, suggesting that global warming gases
produced by human activities could be the cause of
global warming.
The increase in mean temperature varies from region
to region; it is higher in some regions and lower inothers. For instance, Japan’s mean temperature has

A2
A1B
B1
Based on the concentration in2000
20th century

Increase in the mean surface temperatureof the world (℃)

last 100 years. Furthermore, the report indicates that

increased 1.07°C over the last century, according to theJapan Meteorological Agency, which is higher than theworld average of 0.74°C (see bottom of Figure 1). It isalso a fact that the weather has been unusually hot since
the beginning of the 1990s.

(3) Global climate change in the future
The global mean temperature between 2090 and 2099

Year

Figure 2 Temperature increase in the future
A1T, A1B, A1FI, A2, B1 and B2 are the scenarios ofgreenhouse gas emissions (refer to Figure 3 for details). Eachsolid line refers to the average of predicted temperatures basedon multiple models, and each shade, the range of standard
deviation. The orange line is based on the assumption that thegreenhouse gas concentration is maintained at 2000 levels. All
scenarios show that the temperature will increase 0.2°C per
decade up to 2030, while the rate varies after 2030.

is projected to increase by 1.1 to 6.4°C from the 1980 to1990 levels (see Figure 2), whereas a range of 1.4 to 5.8°

Emphasis on economic development

C was projected in the previous report (2001). Whatever

A1
Fast-growing
society

the case may be, the temperature is likely to increase at a

A2
Diversesociety(A1F, A1T, A1B)

rate much higher than that seen in the last century.
The reason predicted temperatures vary so widelyis that they depend a great deal on climate models andsocietal scenarios (see Figure 3 Greenhouse gas emission
scenarios). For instance, the temperature is projected to

Globalization

Sectionalization
B1
Sustainable
development
society

B2
Regional
coexistencesocietyincrease by an average of 1.8°C (1.1 to 2.9°C), according
to the scenario for sustainable development society(B1), where environmental conservation and economic
development go hand in hand, or by an average of 4.0°C (2.4 to 6.4°C), according to the scenario for fastgrowing society, with fossil fuels as the world’s primary−2−

Emphasis on harmony between the environment and economy

Figure 3 Greenhouse gas emission scenarios
Of the four major scenarios above, the A1 scenario is divided
into three sub-scenarios, according to the dependence on fossil
fuels: A1F1 (with emphasis on fossil fuel energy), A1T (withemphasis on non-fossil fuel energy) and A1B (with a balanced
emphasis on all energy sources).

energy sources. However, all scenarios show that the

For instance, white immature kernels occur in many

temperature will increase 0.2°C per decade up to 2030.

cases, with the daily mean temperature exceeding 27°C during the ripening period (the period between

2. Impact of Global Warming on Japan’s
Agriculture, Forestry and Fisheries
The report of Working Group 2 on impacts, adaptationand vulnerability reveals that global warming is having
an impact on nature and society around the world, suchas the melting of glaciers and frozen tundra, advancementin the springtime phenomenon in animals and plants,
and habitat shifts. Global warming is expected to havea serious impact on water resources, ecosystems, foodproduction and other aspects of life.
For agricultural production, low latitudes such as thetropics are more vulnerable than high latitudes to global
warming. The IPCC Fourth Assessment Report predicts
that grain production will decrease in low latitudes andincrease in middle-high latitudes if the global mean
temperature increases 2 to 3°C. This means that global
warming will have a greater impact on developing
countries (most of which are located at low latitudes in
Asia and Africa) than on developed countries such as
Japan. However, a temperature increase of more than 2
to 3°C will probably result in decreased grain production
in both low and high latitudes. The negative impact of
global warming will be greater than the positive impact.
While the IPCC reports summarize the potential
impact on broad regions like Asia and Africa, they do notrefer to those of specific countries. The impact of global
warming on Japan’s agriculture, forestry and fisheries

heading and flowering); all or part of brown rice turns
to milky white. This phenomenon is becoming apparent
in Kyushu, where the daily mean temperature during theripening period is on the rise. Another high-temperature
injury is cracked rice (see Figure 4), where a mature ricegrain cracks due to a rapid change in water content (whichcauses internal strain). The higher the temperature during
the initial ripening period, the more frequently it occurs.
The rind puffing of Satsuma mandarins (see Figure 5)
is a phenomenon where the rind separates from the flesh
due to high temperatures and heavy rain during the laterstages of the ripening period, undermining the quality offruit and storage. The incidence of sunburned fruit (seeFigure 6) is also increasing due to intense sunlight andlack of water during the summer months.
Abnormal coloration of grapes (see Figure 7) is also
attributable to high temperatures, which restrain theformation of anthocyanin and undermine grape quality.
The National Agriculture and Food Research
Organization (NARO) conducted surveys on fruit in2003 and on paddy rice, wheat, soybeans, vegetable,
flowers and livestock in 2005, with questionnaires sent topublic agricultural experiment stations in 47 prefectures,to study the impact of global warming on agriculture.
The results were that all prefectures reported the impact
on fruit, 90% of them on vegetables and flowers, morethan 70% of them on paddy rice and approximately 40%of them wheat, soybeans and livestock (including feed

can be summarized as follows.

(1) Real impact of high temperatures on agriculture,
forestry and fisheries
MAFF conducted a nationwide survey in February
2007 to have a clear picture of the impact of hightemperatures on agricultural production. High-

Figure 4 Cracked rice
A cracked rice grain breaks easily during milling, resulting inpoor eating quality.
It is seemingly a whole grain (left), but slight cracks are visible
when lighted (right, indicated by the arrows).

temperature injury to rice plants, abnormal colorationof fruit and high incidence of pests and diseases wereobserved.

−3−

crops).

high temperatures caused by short-term climate change

Such phenomena are becoming increasingly
widespread, although it remains to be seen if they can(natural fluctuations), but the impact of long-term climatechange (global warming) is no longer negligible.

be attributed to global warming or considered shortterm, sporadic incidents. In fact, while the global mean

(2) Potential impact of global warming on

temperature has increased approximately 1°C over the

agriculture, forestry and fisheries

past century, it is by no means unusual that Japan’s mean

The results of research conducted on the potential

temperature fluctuates within a range of one degree

impact of global warming on Japan’s agriculture, forestry

Celsius from year to year – i.e., natural fluctuations. The

and fisheries show a decrease in the potential paddy

relatively wide range of these natural fluctuations makes

rice yield in some areas, a shift in the areas suitable forit difficult to determine the long-term impact of global

growing fruit, a decrease in beech habitats and changes

warming.

in the distribution and volume of water resources. The

Many of the phenomena observed are probably due toprogress of global warming will probably have serious
impact on Japan’s agriculture, forestry and fisheries.
However, there is one factor that should be kept inmind when making predictions: assumptions. Failure tounderstand such assumptions may cause unnecessary
concerns or, worse, negligence that could slow down
measures against global warming. The following

Figure 5 Rind puffing of Satsuma mandarin due to hightemperatures and heavy rain (left)
The rind separates from the flesh, undermining the quality offruit and storage.

describes how predictions are made.
Model-based simulations are common tools forpredicting the impact of global warming. Specifically,
climate chambers are used to simulate the conditionsof global warming (high temperatures, high CO 2
concentrations, and other such conditions) under whichcrops are grown and animals are fed. Data are thencollected on the impact of higher temperatures on crops
and animals to develop plant (animal) growth models.
With data on future climatic conditions fed into thesemodels, they simulate how crops and animals will

Figure 6 Sunburned fruit due to high temperatures and lack of
water

grow. At the same time, future climatic conditions arecalculated, using supercomputers, based on climate
models and greenhouse gas emission scenarios.

Sunburned fruit results in decreased commercial value.

All models including those for plant growth andclimate simulations involve simplifications of complex
natural phenomena and hence do not necessarily represent
reality. The results of predictions are thus associatedwith uncertainties. Based on this understanding, it isAbnormalimportant to disseminate information to the effect that

NormalFigure 7 Abnormal coloration of grapes due to hightemperatures
Poor coloration results in decreased commercial value.

−4−

this or that could happen in the future, judging from thefindings available to date. The following are some of therepresentative global climate models are used to obtainrepresentative studies.

future climate data, the average of which refers to futuretemperature changes. At the same time, the transplant

1) Potential impact on agriculturea) Paddy rice: Predictions of changes in yields

date is adjusted to maximize the yield, but other factors

Of studies on the impact of global warming on Japan’such as decrease in the yield due to high temperature-s agriculture, many have focused on paddy rice. Briefly,

induced sterility, soil conditions and the impact of pests

yield is expected to increase in the northern region

and diseases are not taken into account.

including Hokkaido and decrease in the southern region

According to predictions based on a paddy riceincluding Kyushu. Put differently, global warming will

growth model, the yield of the Koshihikari variety will

have positive effects on regions where it is too cold todecrease by a maximum of 10% over the next 50 years

grow a given crop, and negative effects on those wherein the sub-Tohoku region, although the yield can be

it is too hot to grow the crop. This observation coincides

increased by 5 to 20% over the same period by adjustingwith predictions made for the impact of global warming

the transplant date. The incidence of high temperature-

worldwide: positive effects are larger in high altitudes

induced sterility, meanwhile, is estimated at less than 5%than in low altitudes.

in all regions for the 2030s, but it is expected to exceed

The results of predictions (using statistical analysis

5% in the Chikushi, Saga, Wakayama and Nobi Plainsof fluctuations based on the relationship between

in the 2090s. (High temperature-induced sterility is a

climatic conditions and yields) show that the yield will

phenomenon where paddy rice is exposed to extremely

increase 13% in Hokkaido and decrease 8 to 15% inhigh temperatures during the flowering period, resulting

the sub-Tohoku region in the 2060s, if the mean annualin poor pollination.)

temperature increases by 3°C (see Figure 8). In this

There is also a need to take into account anotherparticular case, an agroclimatic index (an index based

impact of global warming: an increase in atmospheric

only on temperature and the amount of solar radiation)

CO 2 concentrations. The results of free air CO 2

is used to estimate potential yields. With the assumptionenrichment (FACE) studies (see Figure 9) show thatthat the current atmospheric CO 2 concentration

an increase of CO2 concentration by 200 ppm boosts(approximately 350 ppm) will increase 1% annually, four

the yield by some 15%. (The free-air CO2 enrichment

Black:
Non-paddy fields

Present
800

750

700

2060s
650

600

Agroclimatic index(potential yield,
kg/10a)Figure 8 Impact of global warming on paddy rice yields
Prediction results (using statistical analysis of fluctuations
based on the relationship between climatic conditions andyields) show that the yield will increase 13% in Hokkaido anddecrease 8 to 15% in the sub-Tohoku region in the 2060s, if
the mean annual temperature increases by 3°C.

Figure 9 FACE experiment at Shizukuishi-cho (Iwate
prefecture) to simulate the impact of high CO2 concentrations
CO2 gas is emitted from an octagonal tube according to thedirection of the wind to keep the CO2 concentration (within thearea surrounded by the tube) 200 ppm higher than the ambientconcentration.

−5−

approach involves the artificial emission of CO2 in paddy

the 2060s.

fields to simulate the impact of high CO2 concentrations.)

Data used for the predictions above are derived from

The pores, however, tend to shrink as CO2 concentrations

the method used for studies on paddy rice, and theserise, which could result in increases in the temperature ofpredictions are based on bold assumptions. Only therice ears and risk of high temperature-induced sterility.

mean annual temperature is considered to predict a shiftThus, further studies are needed to determine the grossin the areas suitable for growing apples and Satsuma

impact of high CO2 concentrations.

mandarins. Thus, a number of uncertainties are involved,b) Fruit: Predictions of changes in areas suitable

which are taken into account to come up with possible
scenarios.

for growing fruit
Studies on fruit are also abundant. Adaptation
technique against global warming are particularlyc) Predictions of changes in the production of
livestock and grass

important for fruit growing because fruit trees are usually

There have also been studies on the potential impact

not transplantable. A decades-long production with theof high temperatures on livestock and poultry production.

same tree is required to make fruit growing economically

For instance, chicken production is projected to decrease,viable and, unlike other crops, the sowing period cannot

particularly in western Japan, with approximately 10%

be adjusted.

of the poultry-raising areas experiencing more than a

Data predicting changes in the mean annual

15% decrease in production in August in the 2060s.

temperature suggest that the areas suitable for growing

Figure 11 shows the rates of decease in Japan’s chicken

apples and Satsuma mandarins are moving towards

production in August, which are based on the current andthe north. The temperature range suitable for apples ispredicted mean temperatures (chickens are raised in air-

7 to 13°C; their plantations are widespread, excluding

conditioned chambers). Data used for the predictions arenorthern/eastern Hokkaido and the southwestern plain.

derived from the method used for studies on paddy rice.

With the temperature increasing by 3°C in the 2060s,

For grass, an increase of 4°C in the mean annual

however, all of Hokkaido will become suitable fortemperature over the next century is projected to boost

growing apples, whereas they will no longer grow in the

production by 50%, as temperate grasses decrease andsub-Kanto region (see Figure 10).

tropical grasses increase. However, tropical grass is

The temperature range suitable for Satsuma mandarins

relatively poor in nutrients and the quality of other feedis 15 to 18°C. Likewise, the areas suitable for growing

crops could decline. Additional studies are thus required,

Satsuma mandarins will extend from the southwest

Present

2060s

Present

coastal region to the southern Tohoku coastal region in
2060s

Rate of decrease
(%)
15
5
0

Figure 11 Impact of global warming on chicken production

Right areas (6~14℃)

The rate of decrease in the chicken production in August (atToo hot areas
Too cold areas

present and in the 2060s), with the standard set at 23°C and therate estimated at 5% at 27.2°C and 15% at 30.0°C

Figure 10 Impact of global warming on apple growing
While apple plantations are widespread, excluding northern/eastern Hokkaido and the southwestern plain, they will movetoward the north to include all of Hokkaido in the 2060s,
whereas apples will no longer grow in the sub-Kanto region.

−6−

Chicken production is projected to decrease, particularly inwestern Japan, with approximately 10% of the chicken-raisingareas experiencing more than a 15% decrease in production in
August in the 2060s.

Column 1
Higher CO2 concentrations could boost agricultural production
The positive side of global warming should be considered as well. For example, higher CO2 concentrations
promote photosynthesis of plants. This phenomenon is called the “CO2 fertilization effect,” as it promotes growthand boosts yields. To measure this effect, plants are grown in a climate chamber with high CO2 concentrations
for comparison with those grown under normal conditions. As mentioned earlier, there is also the free-air CO2
enrichment approach (see Figure 9), which is performed in an open-air environment. Results of experiments showthat an increase in CO2 concentration by 200 ppm boosts the yield of wheat and soybeans by some 15% (see Figure
12).

Rice plant (Japan)
Rice plant (China)
Wheat (Maricopa)
Soybeans (Urbana)
Potatoes (Rapolano)
Cotton (Maricopa)

Increase in yields due to high CO2 concentrations (%)
Figure 12 Increase in yield with ambient CO2 concentrations increased by 200 ppm
Review of Hasegawa et al. (2005) plus data on soybeans by Morgan et al. (2005)

with the quality and nutrient aspects taken into account.

(A)Present distribution(B)Present climate

2) Forestry: Predictions of a shift in beech habitats(Fig.A)
Beech forest

Predictions have also been made for forestry. While

Othersthe present distribution of beech species – with climatic,
topographic and soil conditions taken into account –(Fig.B, C and D)
Distribution probability

suggests conditions suitable for their growth, Figure 13
shows a shift in beech habitats due to global warming.
According to a scenario where the mean temperature
increases by 4.9°C between 2081 and 2100, the area
suitable for the growth of beech species will decrease by
91% (see Figure 13-C). Likewise, according to a scenario
where the mean temperature increases by 2.9°C during
the same period, the area will decrease by 63% (seeFigure 13 Impact of global warming on the distribution of
beech forests(C): A scenario based on a climate model developed jointly by the

Figure 13-D). For cedar species, which are on the decline

Center for Climate System Research, the University of Tokyo, anddue to high temperatures and dryness, the results of some(D): A scenario based on a regional climate model of thethe National Institute for Environmental Studies

studies show that the area unsuitable for their growth will

Meteorological Research Institute

The area suitable for the growth of beech species will decreaseby 91% by the end of the 21st century, with an increase of 5°C
in the mean temperature.

increase, based on analysis of present and future climaticconditions and their present distribution.

−7−

Figure 14 Impact of global warming on saury fishing grounds
Saury fishing grounds are predicted to be dramatically decreased 100 years from now due to an increase in watertemperature.

In addition to the predictions for the species mentioned

long-term changes due to global warming. Predictions

above, a variety of studies have been conducted in thefor the next century could hardly give precise images,

field of forestry, some of which include monitoring andbut comparison between those for the next 50 years andmodeling approaches to estimate forest carbon sink.

present conditions could provide a clue to what will
happen in the near future.

3) Fisheries: Predictions of changes in Pacific saury
fishing grounds

3. Japan’s Adaptation Technique to

An increase in water temperature could have asignificant impact on the habitats of aquatic species.
Figure 14 shows expected changes in saury fishinggrounds in September, based on the optimum watertemperature for sauries. Although saury fishing grounds
are located off the coast of the Nemuro Peninsula ineastern Hokkaido (the area circled in red) at present,
sauries were predicted to be scarce in the seas around
Japan about 100 years from now. Similar studies havebeen conducted on a number of species, however, it isdifficult to precisely predict changes in fishing grounds
and seasons as an increase in water temperature causeschanges in ocean currents and feeding environments in

Global Warming
While the previous paragraphs summarize theexisting and potential impact of global warming on
agriculture, forestry and fisheries, adaptation techniques
to such impact on agriculture can be broadly classified
into two categories: development of crop varieties anddevelopment of cultivation techniques. For forestry andfisheries, emphasis is placed on predictions of the impact
of global warming and analysis of its mechanism. The
following sub-paragraphs, therefore, focus on adaptation
techniques in agriculture.

marine ecosystems. It should thus be noted that these(1) Adaptation technique for white immature andpredictions are based on assumptions.
One of the reasons why the impact of global warming
on agriculture, forestry and fisheries 50 to 100 years
from now should be predicted is that the predictions
will enable us to distinguish natural fluctuations from−8−

cracked rice grain
White immature grain caused by high temperaturesduring the ripening period (with a mean temperatureof 27°C or more) undermine the quality of brown rice.
The wihite immature grain can be reduced by avoiding

hinohikari

Nikomaru

Whole grains
74

White immature
kernels9

Othergrains17

Wholegrains
39

White immature
kernels49

Othergrains12

Figure 15 Comparison of the ratio of perfect grains, white immature grain and the other grain between
Nikomaru and Hinohikari in the same heading time. The rate of perfect grain is higher in Nikomaru. (TheNagasaki Agriculture and Forestry Experiment Station, 2005 (high-temperature year)

high temparetures with late planting and direct sowing.

apples, adaptation techniques include a switch toMoreover, as an excessive number of grains and shortage

varieties/species with excellent coloring properties andof nitrogen during the ripening period could promotetechniques to increase the amount of sunlight throughthe occurrence of white immature grains, there is also areflective mulches and other techniques. Likewise,need to optimize the amount and timing of fertilization,

there are techniques to enhance the coloration of grapes

and planting density. The new rice variety Nikomaru,

through girdling (see Figure 16). With the grapevine

breeded in 2005 is recommended because of the low

girdled, sugars photosynthesized in the leaves accumulate

occurrence of white immature kernels, (see Figure 15).

in the branches and leaves. As a result, the sugar content

In fact, the results of four-year experiments carried out inincreases in the upper part from the girdled portion at thethe western Japan show that grain quality of Nikomaru istime of harvesting, which in turn promotes the synthesis

generally superior to that of Hinohikari in most of yearof anthocyanin and enhances the coloration. Recent

and regions.

studies show that the coloration can be further enhanced

Cracked grain, which breaks easily during milling,,with girdling and without bagging. Other coloration

was previously thought to ocuured only by excessive

enhancement techniques include ABA (abscisic acid, adrying of grain with late harvesting. However, recent

plant growth regulator) treatment and optimization of thestudies show that cracked grain promoted by highnumber of fruits per tree.

temperature rises during the early ripening period.

For citrus, typical adaptation techniques for rind

Preventive techniques include late planting, prevention

puffing (caused by high temperatures during the ripeningof early drainage and optimized harvesting.

period) are improved fruit thinning (control of large

The occurence of pecky rice, caused by pecky rice

fruits through cluster fruiting and other techniques),

bugs, is also on the rise, although its relationship withdamage mitigation through plant growth regulator andglobal warming is yet to be unclear. Studies are thus
underway on plant pest forecasting, such as review ofpesticides (including new formulations), mowing aroundpaddy field before heading time and insect forecasting
through pheromone traps.

(2) Adaptation technique for abnormal coloration offruit

Figure 16 Girdling for improvement of coloration (Aki Queen
variety)
Sugars photosynthesized in the leaves accumulate in the
branches and leaves, thereby promoting the synthesis ofanthocyanin and enhancing the coloration.

Of high-temperature injury to fruit, abnormal
coloration is one of the most serious problems. For−9−development of varieties that are resistant to rind puffing

formation does not accelerate as quickly as other varieties(Ishiji, Tamami, among others).

and hence the risk of freezing damage is minimal. The

Global warming raises not only summer but also

Iwainodaichi variety, for that matter, is well adapted

winter temperatures. For instance sleeping disease of

to high-temperature conditions associated with global

greenhouse pears is caused by high temperatures during

warming (see Figure 18).

winter. Too high a temperature during winter retards

Soybean production is expected to decrease due tothe flowering and fruiting of pear trees in spring. Thisdrought. Thus, a system called “FOEAS” is in place tophenomenon can be prevented by spraying cyanamide

control groundwater levels in upland fields convertedor by starting heating after being exposed adequate low

from paddy fields. In addition to irrigation, FOEAS istemperature.

designed for drainage of rainwater.
*Named and registered in 2002, suitable for growing inwest of Kanto, up to southern Kyushu.

(3) Adaptation technique for freezing damage towheat and drought damage to soybeans
High-temperatures do not pose risk of damage towheat, as wheat does not grow in high-temperature(4)Adaptation technique for poor fruit set in
eggplants and techniques to cool strawberries

conditions in summer. However, as winter temperatures

Of vegetables, fruit vegetables are vulnerable to highincrease, the formation of panicles and stalks

temperatures, resulting in poor fruit set. For instance,

accelerates, raising the risk of freezing damage. The

high temperatures induce pollen-sterile eggplants (seeIwainodaichi variety* (see Figure 17), even if planted

Figure 19), while parthenocarpic lines* that are highly

early, is relatively stable during the stalk formation.

resistant to high temperatures are under development.

Global warming could promote its growth, but its stalk

Such lines are expected to be the materials for developing
new varieties well adapted to global warming.
Effecting cooling techniques, meanwhile, are essential
for growing greenhouse vegetables. One such technique
is fog cooling, which involves spraying water, although it
creates humid conditions conducive to pests and diseases.
For this reason, a year-round high-quality cultivation
technique is available, adopting partial cooling of thecrown of strawberries.

Chikugoizumi

Iwainodaichi
Figure 17 Iwainodaichi variety (left)

Rates of healthy andwithered young ears (%)

The Iwainodaichi variety is relatively resistant to freezing
damage, with less stalk formation observed during warm
winter periods.
100
80

Healthy60

Withered40
20Nov. 22

Nov. 15

Hatsuhokomugi

Oct. 21

Nov. 22

Nov. 15

Iwainodaichi

Oct. 21

Nov. 22

Nov. 15The
sowingperiodOct. 210Nourin61

Figure 18 Freezing damage during the sowing season

Figure 19 Poor fruit set of an eggplant due to hightemperature-induced pollen sterilization− 10 −

*Parthenocarpy is the natural or artificially induced
production of fruit without fertilization of ovules.

effective way to reduce greenhouse gas emissions fromthe agriculture, forestry and fishery sectors. As the term
“forest carbon sequestration” suggests, trees and plants

4. Japan’s Mitigation Technique toAddress Global Warming

absorb carbon dioxide, as does the soil (the very basisof agriculture and forestry), depending on how the soil
is managed. What is needed, therefore, is to develop

Six greenhouse gases covered by the Kyoto protocol

technologies to maintain agricultural productivity and atinclude carbon dioxide, methane and nitrous oxide. Of

the same time to mitigate global warming. As mitigationthese, carbon dioxide represents the largest share oftechniques in fisheries center on fuel-efficient fishing

the world’s greenhouse gas emissions. Greenhouse gas

boats, the following is focused on those in agriculture

emissions are usually associated with the combustion

and forestry, which involve ecomanagement.

of fossil fuels and, by extension, with automobiles andfactories. Meanwhile, agriculture, forestry and fisheries(1)Reduction of greenhouse gas emissions fromare all human activities that depend on the circulation of

paddy fields and cattle

nature; they also produce methane and other greenhouse

In agriculture, croplands and livestock are the primarygases. For instance, methane emissions originating fromsources of greenhouse gas emissions. For instance,

paddy fields and livestock such as cattle account for

submerged paddy fields emit methane and drained paddy

some 40% of human-induced methane emissions. It is

fields, nitrous oxide, for which adaptation techniques arethus imperative that these emissions be reduced throughin place.
The IPCC guidelines (2006) show that 1) methane

proper management and techniques.
While energy conservation is part of global warming

is emitted from paddy fields, but not from vegetable

mitigation measures in other sectors such as industry

gardens, 2) methane originating from paddy fields can be

and commerce, taking advantage of the function of

reduced through midseason drainage and 3) nitrous oxide

nature (e.g., carbon sequestration in ecosystems) is an

is emitted both from paddy fields and from vegetable

Column 2
Enormous amount of carbon is stored in the soilPart of plant residues decomposes into stable organic matter (humus), which remains in the soil for hundreds tothousands of years, being separated from the carbon cycle and reducing atmospheric CO2 concentrations. Although acarbon sink is usually associated with forests, soil stores an enormous amount of carbon.
The total amount of organic carbon stored in the soil is estimated at 1.5 trillion tons, approximately double theamount stored in the atmosphere and triple the amount stored in terrestrial plant biomass. Even a slight change in thisamount, therefore, has significant impact on atmospheric CO2 concentrations.
In fact, the amount of organic carbon in the soil, which stood at some 2 trillion tons in the prehistoric age, hasdecreased to some 1.5 trillion tons. Put differently, as much as 0.5 trillion tons of organic carbon have been released
into the atmosphere, with forests converted to croplands, promoting decomposition of soil organic matter. This
amount is more than double the increase in atmospheric carbon over the past 140 years (1850 to 1990) due in largepart to the combustion of oil and other fossil fuels, which is estimated at 230 billion tons. As these figures show, anenormous amount of carbon dioxide has been released from the soil into the atmosphere.
Soil preparation, which maintains the amount of soil organic matter at relatively high levels, is essential not only
for agricultural production but also for global warming mitigation.

− 11 −

gardens, the amount of which increases with the amountincrease the forest area, 2) maintain and increase forestof nitrogen fertilizer applied (the former produce lesscarbon sequestration and 3) make use of wood products

emissions than the latter) (see Table 1).

(enhancement of carbon sequestration and substitution

Specifically, midseason drainage (10 days), followed

for high-energy materials and fossil fuels).

by alternate wetting and drying irrigation (approximately

As Japan has little potential for increasing foresta month and a half, with a cycle of 3-day inundationarea, it needs to opt for the other two effective measuresand 2-day drainage), coupled with application of

combined: enhancement of carbon sequestration innitrogen fertilizer (9kg/10a), inhibits the activity offorests and in wood as home construction materials. Thismethane-producing microorganisms in the soil, thereby

may come as a surprise, but according to some estimatessignificantly reducing methane emissions, compared tothe carbon stored in home construction materials

inundated paddy fields. This practice does not have muchaccounts for some 18% of that stored in forests in Japan.

of an impact on nitrous oxide emissions or rice yield.

Based on Japan’s forest resource database, the Forestry

These observations suggest that midseason drainage, aand Forest Products Research Institute developed acommon practice in Japan, is an effective way to reduce

model designed to calculate the total amount of carbon

greenhouse gas emissions.

sequestration according to a scenario that takes into

Techniques to reduce methane emissions fromaccount both the forest and housing sectors. Simulation

ruminants such as cattle are also available. In the case of

results show that proper management of forests (including

beef cow, for instance, emissions can be reduced by somemulti-storied forests) and improvement of the durability

10% by increasing the proportion of fat-rich beer cakeof homes are effective in enhancing carbon sequestration.

and raw rice bran in the assorted feed to 12%.

Meanwhile, approximately one third of the global
landmass is treeless wasteland, where new afforestation(2) Enhancement of carbon sequestration in forests

techniques – instead of conventional ones using grass

and wood

plants and shrubs – are considered effective mitigation

The report of Working Group 3 on mitigation of

measures. Specifically, techniques being developed

climate change, which is part of the IPCC Fourth

include a planting method that involves blasting of theAssessment Report, proposes to 1) maintain andhardpan (a layer of hard subsoil or clay) near the surface;

Table 1 Emission coefficients, etc. of methane and nitrous oxide originating from paddy
fields and vegetable gardens (IPCC guidelines, 2006)
Paddy fields

Vegetable
gardens

Inundated
paddy fields

Paddy fields withmidseason drainage

Correction coefficients ofmethane emissions, based onwater control (with an inundated
paddy field as 1)

10.52～0.60

0Emission coefficients of nitrous
oxide (as a percentage of theamount of nitrogen in fertilizer)

0.3

0.3

1.0

• Methane is emitted from paddy fields, but not from vegetable gardens; methane originating frompaddy fields can be reduced through midseason drainage.
• Nitrous oxide is emitted both from paddy fields and from vegetable gardens, the amount of
which increases with the amount of nitrogen fertilizer applied (the former produce less emissions
than the latter).
• With both methane and nitrous oxide taken into account, water control involving midseason
drainage, a common practice in Japan, is more effective in reducing greenhouse gas emissions,rather than keeping paddy fields inundated.

− 12 −Column 3
The ocean has huge potential as a carbon sink
The ocean is vast and hence has huge potential as a carbon sink. According to the IPCC Third Assessment Report(2001), an estimated 6.3 billion tons of carbon is released into the atmosphere every year through human activities,
such as combustion of fossil fuels, approximately half of which (3.1 billion tons) is absorbed by Earth. The ocean
ecosystem is thought to absorb 1.7 billion tons and the terrestrial ecosystem is thought to absorb 1.4 billion tons.
These estimates, however, are associated with many uncertainties such as the processes of absorption and release ofcarbon – in particular, those in shallow seas involving seaweeds, shellfish and coral reefs. For this reason, MAFF isworking on the mechanisms of the carbon cycle in seaweed beds, which represent shallow seas.

selection of salt-tolerant, high-growth trees (natural

productivity of agriculture, forestry and fisheries.

hybrid species of Eucalyptus for the salt-encrusted soil;

Likewise, immediate measures for adaptation should

and remediation of high-salinity soil near the surface

be discussed to deal with crop damage such as high-using tubes. At the same time, efforts are underway totemperature injury, while developing heat-resistantconvert unused wood biomass such as scrap wood andvarieties that meet the needs of growers and techniques

forest residue into bioethanol.

that ensure stable agricultural production.
In addition, a more accurate assessment is needed
for the nature, degree and period of the impact of global

5. Topics for Future Studies

warming on agriculture, forestry and fisheries with the
As global warming is considered inevitable, there

findings presented in this report taken into account. The

is a need to continue studying mitigation measuresresults of this assessment will then serve as the basis for(techniques to reduce greenhouse gas emissions fromstudying adaptation measures. As part of the basic studies

agriculture, forestry and fisheries) and, as discussed in

to review drastic adaptation measures including crop

this report, adaptation techniques. MAFF, therefore,switch, it is important to shed light on the physiologicalannounced the “Integrated Strategy for Global

mechanisms and hereditary factors that have something toWarming” on June 21, 2007. The following activities

do with the impact of global warming (a deterioration inwill be emphasized in the “Studies on Global Warming

quality, a decrease in yield, etc.) – a means to accumulate

Countermeasures” with focus on mitigation, adaptation

knowledge that contributes to developing new varieties

and impact assessment.

and production techniques. While appropriate adaptation

For mitigation measures, the key is to shed light on thetechniques should be systematically developed inmechanisms of formation and absorption of greenhouseeach time period from the present to future, any suchgases such as CO2 and to develop their models. These

techniques need to be reviewed from the viewpoint ofbasic studies will serve as the basis for developing

reducing greenhouse gas emissions. That is, adaptation

techniques to manage agroforestry ecosystems designed

and mitigation techniques cannot be separated from eachto minimize greenhouse gas emissions and maximize

other. They should go hand in hand.

soil and forest carbon sequestration. In so doing, thecarbon balance should be evaluated through life cycle

Authors: Yasuhito Shirato, Akira Fukushima, Naoki

assessment (LCA), thereby developing an integrated

Ogata, Takayoshi Ohara, Kenji Kawashima, Hisatomi

system for the management of agricultural techniques

Harada, Tatsuhiko Yamada, Hirofumi Furuita, Ohtani

and ecosystems to reduce greenhouse gas emissions. At

Toshiothe same time, due consideration should be given to the− 13 −

References• The IPCC Fourth Assessment Report
The Working Group 1 (physical science basis)
http://ipcc-wg1.ucar.edu/index.html
The Working Group 2 (impacts, adaptation and vulnerability)
http://www.ipcc-wg2.org/
The Working Group 3 (mitigation of climate change)
http://arch.rivm.nl/env/int/ipcc/• Integrated Strategy for Global Warming by the Ministry of Agriculture, Forestry and Fisheries
http://www.maff.go.jp/kankyo/ondanka/index.html (in Japanese)• Report on Tentative Adaptation Measures for Agricultural Items
http://www.maff.go.jp/kankyo/honbu/04/ref_data03-2.pdf (in Japanese)• Survey on the Impact of Global Warming on Agriculture by the National Agriculture and Food Research Organization(NARO)
http://fruit.naro.affrc.go.jp/kajunoheya/ondan/ondanka.pdf (in Japanese)− 14 −

Sources of Figures and Tables
Figure 1: Website of the Japan Meteorological Agency http://www.data.kishou.go.jp/climate/cpdinfo/temp/index.html
Figure 2: Report of the Working Group 1, the IPCC Fourth Assessment Report
Figure 3: Prepared based on the report of the Working Group 1, the IPCC Third Assessment Report
Figure 4: Presented by Kenji Nagata, the National Agricultural Research Center for Tohoku Region, the National
Agriculture and Food Research Organization
Figure 5-7: Reference materials of the Third Task Force on Global Warming and Forest Carbon Sink, MAFF, http://www.
maff.go.jp/kankyo/honbu/03/data05.pdf
Figure 8: Hayashi, Ichigouoka, Yokozawa, Toritani, Goto. 2001. The impact of global warming on the potential
characteristics of Japan’s paddy rice cultivation. Chikyu Kankyo Vol. 6, No.2: 141-148
Figure 9: Hasegawa. 2006. The impact of global warming and high atmospheric CO2 concentrations on the growth andyield of paddy rice (the National Institute for Agro-Environmental Sciences): 31-37
Figure 10: Predictions of a shift in the areas suitable for growing apples and Satsuma mandarins due to global warming(2002), the National Institute of Fruit Tree Science
Figure 11: Yamazaki, et al. 2006. The impact of global warming on Japan’s chicken production, estimated based onchanges in the mean temperature. The Japan Society of Animal Science Bulletin 77 (2): 231-235
Figure 12: Hasegawa. 2006. The impact of global warming and high atmospheric CO2 concentrations on the growth andyield of paddy rice (the National Institute for Agro-Environmental Sciences): 31-37
Figure 13: Climatic factors influencing the distribution of natural forests and the potential impact of global warming(especially on beech species). Chikyu Kankyo Vol. 11, 2006.
Figure 14: Kuwahara, et al. 2006. Predictions of a shift in the distribution of Japan’s aquatic life due to global warming.
Chikyu Kankyo Vol. 11, No. 1: 49-57
Figure 15: Prepared based on photos and data provided by the Nagasaki Agriculture and Forestry Experiment Station
Figure 16: Girdling and non-bagging treatment in greenhouses designed to enhance the coloration of the Aki Queen
variety (a red grape variety) (2005), the National Agricultural Research Center for Kyushu Okinawa Region
Figure 17: Winter-type wheat Iwainodaichi (a new early season cultivar); the website of the National Agricultural
Research Center for Kyushu Okinawa Region, the National Agriculture and Food Research Organization (NARO)(http://www.knaes.affrc.go.jp/seikadb/05/5-10.html)
Figure 18: Prepared based on “The advancement of the wheat cropping season using Iwainodaichi in Aichi prefecture(2001), Agriculture in the Kanto, Tokai and Hokuriku regions, the National Agriculture and Food Research
Organization (NARO)
Figure 19: Presented by Kaoru Kikuchi, the National Institute of Vegetable and Tea Science, the National Agriculture andFood Research Organization (NARO)
Table 1: The emission coefficients of methane and dinitrogen oxide originating from paddy fields and vegetable gardens,
according to the IPCC guidelines (2006).

− 15 −

This report is accessible from following URL
http://www.s.affrc.go.jp/docs/report/report23/no23e.pdf

Report on Research and Development in Agriculture, Forestry and Fisheries No.23 (2007)

Impact of Global Warming on Agriculture, Forestry and Fisheries and Possible Countermeasures in Japan
December 26, 2007 (Japanese edition)
June 10, 2008 (English edition; directly translated from Japanese edition)
Edited by: Agriculture, Forestry and Fisheries Research Council, MAFF
Compiled and issued by: Agriculture, Forestry and Fisheries Research Council Secretariat, MAFF
1-2-1 Kasumigaseki, Chiyoda-ku, Tokyo 100-8950
http://www.s.affrc.go.jp/
www@s.affrc.go.jp