Climate Change Present and Future

2008

April 2008

Japan Meteorological Agency

Preface
The Intergovernmental Panel on Climate Change (IPCC) released
its Fourth

Assessment Report last year summarizing the newest

scientiﬁc understanding of global warming. The report says thatwarming of the climate system is unequivocal, and that most of theobserved increase in global average temperatures since the mid20th century is very likely due to the observed increase in anthropogenic greenhouse gas (GHG) concentrations. In addition to mitigation to reduce GHG emissions, the report points out the importanceof adapting to the inevitable eﬀects and risks of global warming.
The Japan Meteorological Agency (JMA) provides information
based on operational earth observation and monitoring (including
long-term air and sea-surface temperature changes) as well as theresults of climate projections in reports such as Global Warming
Projection in order to provide a basis for adaptation planningagainst global warming. Through the timely provision of weather
warnings and advisories, it also supports adaptation to theincreased occurrence of extreme weather events (such as heavy
rainfall) expected as a result of global warming. JMA also contributes to the enrichment of scientiﬁc knowledge to support future
mitigation planning by providing basic data and information on theemission/absorption of carbon dioxide through GHG measurements
and the operation of the World Data Centre for Greenhouse Gases(WDCGG).
This brochure describes the current status of climate change andfuture global warming projection, and introduces JMA s activities
in regard to climate observation, monitoring and projection.

Contents

Part I Current State of Climate Change
Chapter 1. Current State of Greenhouse Gases
1. Atmospheric Greenhouse Gas Concentrations

1
1- Highest level on record 2. Oceanic Greenhouse Gas Concentrations

3- The western North Paciﬁc is absorbing CO2 Chapter 2. Long-term Trends of Climate Change
1. Global Surface Temperature and Precipitation

4
4- The global temperature is rising 2. Surface Temperature and Precipitation in Japan5- Japan s air temperature is also rising 3. Sea Surface Temperature and Sea Level around Japan

6- The rate of SST rise around Japan is higher than the
global average 4. Sea Ice Extents in the Arctic Sea and in the Sea of
Okhotsk

7- Sea ice extents are decreasing 5. Phenological Events in Japan

8- Cherry blossom blooming dates are becoming earlier 6. Number of Tropical Cyclones Formed in the Western
North Paciﬁc

9- No signiﬁcant trends are found Chapter 3. Surface Climate and Extreme Events in Recent
Years
1. Major Extreme Events in Japan and around the World

1010- Extreme high temperature events are frequently
observed 2. Long-term Trends of Extreme Events in Japan

12- Extreme high temperature events are increasing -Part II Global Warming Projections
Chapter 1. Global Projections (based on IPCC AR4)

14

Chapter 2. Projections around Japan

16

Part III The Japan Meteorological Agency s Eﬀorts for
Monitoring and Projection of Climate Change
Chapter 1. Ocean Observation and the Argo Project18

Chapter 2. World Data Centre for Greenhouse Gases(WDCGG)

19

Chapter 3. Asia s First Long-Term Atmospheric
Reanalysis

20

Chapter 4. Establishment of an Advisory Panel on Extreme
Climate Events

21

Chapter 5. Tokyo Climate Center (TCC)

22

Chapter 6. Research and Development for Global Warming
Projection

23

back cover right-side picture : courtesy of Japan Center for Climate Change Actions（http://www.jccca.org/)

Part I Current State of Climate Change
Chapter 1.

1

Current State of Greenhouse Gases

Atmospheric Greenhouse Gas Concentrations- Highest level on record -Greenhouse gases such as carbon dioxide(CO2), methane (CH4) and nitrous oxide (N2O)
contribute signiﬁcantly to global warming.
According to analyses of CO2 from 1983 andN2O from 1980, the global average of theannual mean atmospheric CO2 and N2O concentrations for 2006 reached record highs.
Although growth rates of global mean CH4
concentration have been close to zero in recent
years, the global mean CH4 concentration for2006 remained at its highest level.
CO2 is the most signiﬁcant contributor to
global warming of all the human-induced gases.
Global mean atmospheric CO2 concentrations(Figure 1.1.1) have been increasing year by year
because of human activities such as fossil fuelconsumption. Growth rates of CO2 have also
increased in recent years.
Figure 1.1.2 shows the estimated distributionof CO2 concentrations, which change seasonally due mostly to the inﬂuence of vegetation
activities. In winter, CO2 concentrations overcontinents are higher than those over theocean due to inactive plant photosynthesis,
and vice versa in summer.
These facts are ascertained through theanalysis of greenhouse gas data observed
around the world and reported to the WMO
World Data Center for Greenhouse Gases(WDCGG) located at the Japan Meteorological
Agency (JMA) (see Chapter 2 of Part III).

390

380

CO2(ppm)

370

360

350

340

330

1985

1990

1995

2000

2005

Year

Figure 1.1.1 Time-series of global mean CO2 concentrations
Blue dots: monthly concentration Thin red line: deseasonalized concentration

1

Part I Current State of Climate Change

Chapter 1.

Current State of Greenhouse Gases

370

380

390

400

Figure 1.1.2 Estimated distribution of CO2 concentrations
Left: February 2006 Right: August 2006

ever at all these stations, as also observed
generally worldwide.
Moreover, the N2O and CH4 concentrations
observed at these stations in 2007 wereamong the highest on record.

Figure 1.1.3 shows a time series of atmospheric CO2 concentrations at three stations(Ryori, Minamitorishima and Yonagunijima)
where JMA has carried out long-term monitoring. Concentrations in 2007 were the highest

110E

120E

130E

140E

150E

160E

50N

40N

CO2 concentration (ppm)

400
390
380
370
360
350
30N

340

1988

1990

1992

1994

1996

1998

2000

2002

2004

2006
Year

20N

Figure 1.1.3 Left: JMAʼs three observational stations for greenhouse gases; Right: Time-series of monthlymean atmospheric CO2 concentrations (lines with dots) and deseasonalized concentrations (thin lines) at
Ryori, Minamitorishima and Yonagunijima.

2

Part I Current State of Climate Change

Current State of Greenhouse Gases

2

Oceanic Greenhouse Gas Concentrations- The western North Paciﬁc is absorbing CO2 -The IPCC Fourth Assessment Report (AR4) shows

Figure 1.1.4 shows a time-series graph of oceanicthat the ocean has so far absorbed about one third ofand atmospheric CO2 concentrations along 137°
E in

net anthropogenic CO2 emissions. In order to predict

winter. The oceanic CO2 concentration rose by 40

future atmospheric CO2 concentration and global

ppm between 1984 and 2007. The growth rate inwarming, it is very important to evaluate the amount

oceanic CO2 is comparable to that in atmosphericof CO2 taken up by the ocean. On a regional scale, theCO2. These data suggest that the western North

amount of oceanic CO2 absorption changes from

Paciﬁc is acting as a sink for atmospheric CO2, andplace to place and from season to season. These

that there has been no appreciable change in thegeographical and seasonal non-uniformities make itcapacity for CO2 uptake by the ocean in this regiondiﬃcult to estimate global oceanic CO2 uptake. In

over the past 20 years.

order to reduce the uncertainty of estimations, JMA
conducts marine CO2 observations in the air andseawater of the western North Paciﬁc using research
vessels.

400

380
CO2 concentration (ppm)

Chapter 1.

360

340

320

300
1985

1990

1995

2000

2005 Year

Figure 1.1.4 Time series of oceanic (blue lines) and atmospheric (pink lines) CO2 concentrations
averaged between 7°
N and 33°
N along 137°
E in winter from 1984 to 2007.

3

Part I Current State of Climate Change

Chapter 2. Long-term Trends of Climate Change

1

Global Surface Temperature and Precipitation- The global temperature is rising -ﬂuctuations on diﬀerent time scales ranging
from several years to decades superimposed on
global warming caused by the increase ofgreenhouse gases such as CO2. According to
the IPCC AR4, most of the observed increase inglobal average temperatures since themid-20th century is very likely due to theobserved increase in anthropogenic greenhouse gas concentrations.
Figure 1.2.2 shows a time series of annual
precipitation ratios from 1880 to 2007 overthe globe (for land areas only). There has notbeen any remarkable trend.

Anomaly (℃)

JMA operationally analyzes global surface
temperatures and precipitation to monitor
global warming.
Figure 1.2.1 shows annual anomalies of global
average surface temperature (the average ofthe near-surface air temperature over land andthe SST). The annual mean surface temperature
has varied along diﬀerent time scales ranging
from a few years to several decades. On alonger time scale, global average surface
temperatures analyzed by JMA have been rising
at a rate of 0.67°
C per century since 1891. The
trend of the warming can be explained by

Ratio (%)

Figure 1.2.1 Annual anomalies in surface temperature (i.e. the average of the near-surface air temperature over land and the SST) from 1891 to 2007. Anomalies are deviations from the normal (i.e. the 19712000 average). The bars indicate anomalies in surface temperature for each year. The blue line indicatesthe ﬁve-year running mean, and the red line indicates the long-term linear trend.

Figure 1.2.2 Annual precipitation ratios (land only) from 1880 to 2007. The bars indicate the ratios ofannual precipitation to the normal (i.e. the 1971-2000 average). The green line indicates the ﬁve-year
running mean.

4Part I Current State of Climate Change

Chapter 2. Long-term Trends of Climate Change

2

Surface Temperature and Precipitation in Japan- Japan s air temperature is also rising -Figure 1.2.4 shows a time series of annual
precipitation ratios from 1898 to 2007 in
Japan. No long-term trend is detected in thenationwide annual precipitation ratios. Meanwhile, the ﬂuctuations seem to have gradually
increased for the last few decades.

Anomaly (℃)

In order to monitor long-term changes insurface temperature and precipitation, JMA has
analyzed observations at its stations since
1898.
Figure 1.2.3 shows annual anomalies of
average surface temperatures from 1898 to2007 in Japan. The anomalies have been rising
at a rate of 1.10°
C per century since 1898.
Surface temperatures in Japan have been rising
at a faster rate than over the globe.

Ratio (%)

Figure 1.2.3 Annual surface temperature anomalies from 1898 to 2007 in Japan. The bars indicate
anomalies from the normal (i.e. the 1971-2000 average of the 17 stations that have not been highlyinﬂuenced by urbanization and have continuous long-term records). The blue line indicates the ﬁve-year
running mean, while the red line indicates the long-term trend.

Figure 1.2.4 Annual precipitation ratios from 1898 to 2007 in Japan. The bars indicate annual precipitation ratios to the normal (i.e. the 1971-2000 average of the 51 stations). The green line indicates theﬁve-year running mean.

5

Part I Current State of Climate Change

Chapter 2. Long-term Trends of Climate Change

3

Sea Surface Temperature and Sea Level around Japan- The rate of SST rise around Japan is higher than the global average -According to the IPCC AR4, long-term trends
of regional average surface temperatures (theaverage of the near-surface air temperature
over land and the sea surface temperature(SST) of the region) diﬀer signiﬁcantly fromplace to place.
According to JMA s investigation, the global
average SST has risen by 0.5ºC over the last
100 years, while SSTs have risen by 0.7ºC to
1.7ºC per century around Kyushu and Okinawa,
the central and southern Sea of Japan, and theseas south of Japan (Figure 1.2.5). The rate of
SST rise around Japan is higher than that of the
global ocean.
According to the AR4, the total 20th-century
increase in the global average sea level isestimated to be 0.12 to 0.22 m, and the sea
level change is not geographically uniform.
JMA s analysis over the last 100 years showsthat there is no clear long-term trend in sea
levels along the Japanese coast, but an approximate 20-year (bidecadal) variation is dominant(Figure 1.2.6). The extent to which global
warming aﬀects sea levels along the Japanese
coast is unclear. However, since 1985, theaverage sea level has risen at a rate of 3.2
mm/year. (Figure 1.2.6).

Figure 1.2.5 Rates of mean SST rise around
Japan by area from 1900 to 2007 (ºC/100
years). Areas marked * are those where no
signiﬁcant value is estimated due to large SST
variability such as decadal oscillation.

50°
N

40°
N

30°
N

20°
N
120°
E

130°
E

Sea Level Variation〔cm〕

8

4
2
0
-2
-4
-6

6

150°
E

Figure 1.2.6 Variations in sea
level along the Japanese
coast. The open circles andblue line represent mean sea
level anomalies at the tidal
stations along the Japan coastand their ﬁve-year runningmean respectively. The normal
is the 1971-2000 average.

6

1900

140°
E

Figure 1.2.5 Rates of mean SST rise around Japanby area from 1900 to 2007 (ºC/100 years). Areas
marked ʻ*ʼ are those where no signiﬁcant value isestimated due to large SST variability such as
decadal oscillation.

1920

1940

1960

1980

2000

Year

Part I Current State of Climate Change

Chapter 2. Long-term Trends of Climate Change

4

Sea Ice Extents in the Arctic Sea and in the Sea of Okhotsk- Sea ice extents are decreasing -According to satellite observation data since1978, an overall downward trend in the extent
of Arctic sea ice is found, especially in summer,
as shown in Figure 1.2.7 from the IPCC AR4. In
September 2007, the extent of Arctic sea ice
was the lowest on record.
Sea ice reﬂects most of the sunlight thatreaches it back into space, and acts as a kind oflid that prevents heat exchange between theocean and atmosphere. The melting of sea ice
reduces the reﬂection of sunlight, which causes
further warming. Reduced sea ice can therefore
accelerate global warming.
In the IPCC AR4, sea ice is projected to shrink
both in the Arctic and in the Antarctic. Some
projections suggest that arctic sea ice in latesummer will disappear almost entirely by thelatter half of the 21st century. In winter, sea ice
is formed in the Sea of Okhotsk, which is one of

the lowest-latitude seas where sea ice isobserved. The sea ice extent in the Sea of
Okhotsk may also be aﬀected by global warming. JMA monitors sea ice conditions in the Seaof Okhotsk as well as in the Arctic and Antarctic seas to analyze variations in sea ice extent
due to global warming.
Although the sea ice extent in the Sea of
Okhotsk has large interannual variations, adownward trend for the period from 1971 to2007 is seen (Figure 1.2.8). The estimatedrate of decline in the maximum sea ice extent is-5.52 × 104 km2 every 10 years, corresponding
to a 15% decrease over about 40 years. From
December 2005 to May 2006, the accumulated sea ice extent in the Sea of Okhotsk was
the lowest since 1971, and the seasonal
maximum was the second lowest since 1971
(Figures 1.2.8 and 1.2.9).

million square kilometers
8.0
7.5
7.0
6.5
6.0
5.5
1980

1985

1990

1995

2000

Year
2005

Figure 1.2.7 Minimum arctic sea ice extent from1979 to 2005 in summer. The dots indicate annual
mean values, while the smooth blue line shows
decadal variations (IPCC AR4).

ten thousand square kilometers

160
150
140

Figure 1.2.9 Sea ice extent in the Sea of Okhotsk (10March). Left: Climatological distribution (1971-2000
average). Right: Distribution in 2006 (maximum sea ice
extent recorded on 10 March 2006).

130
120
110
100
90
80
1971 1975 1979 1983 1987 1991 1995 1999 2003 2007 Year

Figure 1.2.8 Maximum sea ice extent in the Sea of
Okhotsk

7

Part I Current State of Climate Change

Chapter 2. Long-term Trends of Climate Change

5

Phenological Events in Japan- Cherry blossom blooming dates are becoming earlier -JMA has observed botanical, zoological and entomo-cherry blossom blooming front as of 1st April. This

logical events (blooming, ﬁrst sighting and birdsong)ﬁgure indicates that the front has shifted about 100

since 1953. This practice is known as phenologicalkilometers north on average over the last four

observation.

decades.

Over the last ﬁve decades, the cherry blossom

It is well known that cherry blossom blooming andblooming date has become 4.2 days earlier, and theautumnal tints are closely related to air temperature.

date of autumnal tints of the Japanese maple has

It is suggested that the long-term trends seen in

become 15.6 days later (Figure 1.2.10).

these phenomena are due to global warming and/or

+10

-0.2

+5

-1.0

0

0.0

-5

+1.0

-10

+2.0

-15
1950

1960

1970

1980

1990

+3.0
2000 Year

+15

-0.3

+10

-0.2

+5

-1.0

0

0.0

-5

+1.0

-10

+2.0

-15
1950

1960

1970

1980

1990

+3.0
2000 Year

Figure. 1.2.10 (a) Deviations from the normal
blooming dates (pink line) and anomalies of mean
temperature in February/March/April (blue line) ‒both of which are averaged over Japan ‒ and thelinear trend of blooming dates (green line).
(b) Deviations from the normal of autumnal tint
dates (red line) and anomalies of mean temperature in September/October/November (blue line) ‒both of which are averaged over Japan ‒ and thelinear trend of autumnal tint dates (green line). The
normals are the average values for 1971-2000.

8

Anomalies ofspring mean temperature (℃)-0.3

urbanization.

Anomalies ofautumn mean temperature (℃)+15

Deviation fromnormal autumnal tint date (day)Deviation fromnormal blooming date (day)Figure 1.2.11 shows the long-term change in the

Picture 1.2.1 Many people enjoy viewing
cherry blossoms in full bloom in Tokyo.

Average for1998-2007

Average for
1961-1970

Figure 1.2.11 Geographical change in the cherry
blossom blooming front as of April 1st showing
the blooming date isolines. The bold and dottedlines represent the average blooming dates for
1998-2007 and 1961-1970 respectively.

Part I Current State of Climate Change

Chapter 2. Long-term Trends of Climate Change

6

Number of Tropical Cyclones Formed in the western North Paciﬁc- No signiﬁcant trends are found -The IPCC AR4 shows that there is observational

Focusing on recent years, the number of approach-evidence suggesting an increase in intense tropicaling tropical cyclones has been above normal, while

cyclone activity in the North Atlantic since about

the number forming has been below normal.

1970.

The number and ratio of tropical cyclones forming

There is no upward/downward trend in the number ofwith maximum winds of 64 knots or higher also

tropical cyclones formed in the western North Paciﬁc,shows no signiﬁcant trend for the period 1977-2007

those that approached Japan, or those that hit Japan(Figure 1.2.13).

in the period 1951-2007 (Figure 1.2.12).
40

Number

30

20

10

0
1950

1960

1970

1980

1990

2000

2010 Year

40

80％

30

60％

20

40％

10

20％

0

0％

1975

1980

1985

1990

1995

2000

2005

Rate

NumberFigure 1.2.12 Number of tropical cyclones (34 knots or higher) that formed in the western North Paciﬁc(top), those that approached Japan (middle) and those that hit Japan (bottom). The thin, thick and dashedlines represent the annual values, ﬁve-year running means and normal values (1971‒2000 average)
respectively.

2010 Year

Figure 1.2.13 Number (bottom) and ratio (top) of tropical cyclone formations with maximum winds of 64
knots or higher. The thin and thick lines represent annual values and ﬁve-year running means respectively.

9Part I Current State of Climate Change

Chapter 3. Surface Climate and Extreme Events in Recent Years

1

Major Extreme Events in Japan and around the World- Extreme high temperature events are frequently observed -Extreme climatic events have caused disasters

70,000 fatalities.

across the world. Extremely high temperatures have

In Australia, extremely light precipitation amounts

frequently been observed in East Asia, Europe and thehave been observed continuously since 2003,

tropics since 2003 (Figure 1.3.1). In particular, heatcausing severe agricultural damage (Figure 1.3.2).

waves in Europe in summer 2003 caused more than
30°
W
90°
N

0°

30°
E

60°
E

90°
E

120°
E

150°
E

180°

150°
W

120°
W

90°
W

60°
W

30°
W
90°
N

60°
N

60°
N

30°
N

30°
N

0°

0°

30°
S

30°
S

60°
S

60°
S

90°
S
30°
W

0°

30°
E

60°
E

90°
E

120°
E

150°
E

180°

150°
W

120°
W

90°
W

90°
S
60°
W
30°
W
CPD/JMA

Figure 1.3.1 Frequencies of extremely high/low temperature in 2003-2007 are marked with upper/lower
red/blue semicircles. The size of the semicircles illustrates the ratios of extremely high/low temperature
occurrence based on monthly observation for the year in each 5°× 5°grid box.

Figure 1.3.2 Major weather-related disasters worldwide in 2003-2007

10

Part I Current State of Climate Change

Chapter 3. Surface Climate and Extreme Events in Recent Years

In Japan, the number of fatalities and individuals

The ﬁgures related to human damage (such as

unaccounted for as a result of weather-relatedheatstroke and death from intense heat) as well as

disasters is decreasing. However, there have been

agricultural and marine product damage due toseveral exceptions over the last ﬁve years. The

extreme high temperatures show an increasing trend,

number in 2004 exceeded 300 people for the ﬁrst

especially those for heatstroke (Figure 1.3.4). In

time since 1993, mainly due the record total of ten

1994 when a record-breaking hot summer was

typhoons that hit Japan. The number exceeded 200

experienced, the ﬁgures for such heat-induced

people for successive years in 2005 and 2006

damage were the highest so far.

(Figure 1.3.3, Table 1.3.1).

2005

2003

2001

1997

1999

1995

1993

1991

1987

1989

1985

1983

1981

1977

1975

1973

Year

Heats troke victims
Heat-related damage

1971

2005

2003

2001

1997

1999

1995

1993

1991

1987

1989

1985

1983

1981

1977

45
40
35
30
25
20
15
10
5
0

1975

Cases

1800
1600
1400
1200
1000
800
600
400
200
0

1973

People

900
800
700
600
500
400
300
200
100
0

1971

PeopleYear

Figure 1.3.3 Number of fatalities and individuals
Figure 1.3.4 Number of cases of heat-related
unaccounted for as a result of weather-related
damage (thin line) and heatstroke victims (bars)
disasters* These ﬁgures are based on reports by prefectural governments in Japan
Table 1.3.1 Major weather-related disasters in Japan over the last ﬁve years
2007
Typhoon (MAN-YI) and Baiu
July
front
2006

Heavy rains in many districts across Okinawa to southern Tohoku;
gales in Okinawa, the Paciﬁc side of western Japan and the Izu
Islands

Low pressure development October

Gales and heavy rains from Kinki to Hokkaido; wrecks and alpine
accidents in many districts

Baiu front

Heavy rains in Kyushu, San-in, Kinki, Hokuriku, especially in Nagano
and Kagoshima prefectures

July

2005
Strong winter monsoon

December 2005 Heavy snow from December to early January, causing many fatalities
from accidents in snow-removal
to March 2006

Typhoon (NABI) and stationSeptember
ary front
2004
Typhoon (TOKAGE) andOctoberstationary front
Typhoon(MEARI)
and
Septemberstationary front

Gales, heavy rains and high waves continued for many hours inKyushu, Shikoku and Chugoku; extremely heavy rains exceeding 100
mm/hour in parts of Tokyo and Saitama prefectures

Typhoon (SONGDA)

SeptemberGales and gusts from Okinawa to Hokkaido; maximum wind speeds of
60.2 m/s in Hiroshima, 50.2 m/s in Sapporo

Baiu front

July

Heavy rains in Gifu and Fukui prefectures; daily precipitation
exceeding the average monthly total in Miyama, Fukui Prefecture

Baiu front

July

Record-breaking heavy rains in Niigata and Fukushima prefectures

July

Extremely heavy rains exceeding 50 mm/hour in northern Kyushu

Heavy rains in many districts; massive damage from landslides andﬂoods
Extremely heavy rains exceeding 130 mm/hour in Mie Prefecture;
Daily precipitation of 740.5 mm in Owase

2003
Baiu front

11

Part I Current State of Climate Change

Chapter 3. Surface Climate and Extreme Events in Recent Years

2

Long-term trend of extreme events in Japan- Extremely high temperature events are increasing -The occurrence of extremely high monthly tempera-tion amounts increased signiﬁcantly in the period

tures* in Japan increased signiﬁcantly in the period

from 1901 to 2006. Both extremely heavy and lightfrom 1901 to 2006, while that of extremely low

precipitation amounts increased after the 1980s; themonthly temperatures decreased. The occurrence ofvariability of precipitation amounts increased (i.e.

extremely high temperatures increased remarkably inboth extremely heavy and light monthly precipitation

the 1980s, and the average for the most recent 30

amounts have appeared frequently) (Figure 1.3.6).

years (1977-2006) reached ﬁve times the level seen

The IPCC AR4 shows that heat waves, heavy rainsat the beginning of the 20th century (1901-1930)

and droughts are very likely to increase in most areas(Figure 1.3.5).

across the world in the late 20th century.

Annual number of occurrences per station

The occurrence of extremely light monthly precipita4

3

2

1
0.45
0
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
Extremely high monthly temperature

Extremely low monthly temperature

11-year running mean

11-year running mean

Figure 1.3.5 Annual number of occurrences of extremely high/low monthly mean temperatures in Japan
1.60

Annual number of occurrences per station

1.5

1

0.5

0.45

Year
0
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
Extremely heavy monthly precipitation

Extremely light monthly precipitation

11-year running mean

11-year running mean

Figure 1.3.6 Annual number of occurrences of extremely heavy/light monthly precipitation amounts in
Japan

12

* The threshold of extremely high/low temperature or heavy/light precipitation is deﬁned as the fourthhighest/lowest value for the month over the period from 1901 to 2006.

Part I Current State of Climate Change

Chapter 3. Surface Climate and Extreme Events in Recent Years

In Japan, the number of extremely hot days (the1.3.8), while cold nights (the annual number of days

annual number of days with a maximum temperature

with Tmin of < 0ºC) decreased signiﬁcantly over the(Tmax) of ≧ 35ºC) increased signiﬁcantly in the

period from 1931 to 2006 (Figure 1.3.9).

1980s (Figure 1.3.7). Extremely hot nights (theThe annual number of days with daily precipitation

annual number of days with a minimum temperatureof ≧ 200 mm increased signiﬁcantly over the period(Tmin) of ≧ 25ºC) also increased signiﬁcantly (Figure

from 1901 to 2006 (Figure 1.3.10).

8
6
4
2
0
1930

Annual number of days per station

Number of days with Tmin ≧ 25℃
30

１地点あたりの年間日数

Annual number of days per station

Number of days with Tmax ≧ 35℃
10

Year
1940

1950

1960

1970

1980

1990

2000

10

0
1930

2010

Figure 1.3.7 Annual number of days with maximum temperatures of ≧ 35ºC (annual number ofdays per station). The thin line indicates thevalues for each year, and the thick line indicatesthe 11-year running mean value.

20

1960

1970

1980

1990

2000

2010

Number of days precipitation ≧ 200mm

Number of days with Tmin ＜ 0℃
100

80
60
40
20
Year
1940

1950

1960

1970

1980

1990

2000

2010

Figure 1.3.9 Annual number of days withminimum temperatures of < 0ºC. The same as
Figure 1.3.7, but for a minimum temperature of <0ºC

Annual number of days per station

Annual number of days per station

1950

Figure 1.3.8 Annual number of days withminimum temperatures of ≧ 25ºC. The same as
Figure 1.3.7, but for a minimum temperature of ≧
25ºC

100

0
1930

Year
1940

80
60
40
20
Year
0
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

Figure 1.3.10
Annual number of days with
precipitation of ≧ 200 mm. The same as Figure
1.3.7, but for precipitation of ≧ 200 mm.

13Part II Global Warming Projections
Chapter 1.

Global Projections(based on IPCC AR4)

Many climate model results were made available atof about 0.2°
C per decade is projected for a range ofthe time of the IPCC AR4, which enabled us to createcases in the Special Report on Emissions Scenarios

best estimates and uncertainty ranges for climate(SRES). Even if the concentrations of all GHGs andprojections. There is high agreement and muchaerosols were kept constant at the levels seen inevidence to suggest that, with current climate change

2000, further warming of about 0.1°
C per decade

mitigation policies and related sustainable develop-

would be expected. Afterwards, temperature projec-

ment practices, global GHG emissions will continue totions increasingly depend on speciﬁc emission

grow over the next few decades. Continued GHG

scenarios (Figure 2.1.1). The best estimate and likely

emissions at or above current rates would cause

range for global average surface air warming is 1.8

further warming and induce many changes in the[1.1-2.9]°
C for the low scenario (B1), 2.8 [2.0-5.4]°
C

global climate system during the 21st century thatfor the middle scenario (A1B), and 4.0 [2.4-6.4]°
C forwould very likely be larger than those observed during

the high scenario (A1FI).

the 20th century. For the next two decades, warming

5.0
4.0
3.0
2.0
1.0
0
B1
A1T
B2
A1B
A2
A1FI

Global surface warming (℃）

6.0

-1.0
1900

2000
Year

2100

Figure 2.1.1 The solid lines represent multi-model global averages of surface warming for scenarios A2,
A1B and B1. The bars to the right of the ﬁgure indicate best estimates (the solid line within each bar)and the likely range assessed for the six SRES marker scenarios at 2090-2099. All temperatures are
relative to the period 1980-1999.

14

Part II Global Warming Projections
Chapter 1.

Global Projections(based on IPCC AR4)
Projected regional-scale changes include: greater

likely increase in precipitation in the high latitudes,

warming over land and in most northern high latitudes,

and a likely decrease in most subtropical land regions

and lesser warming over the Southern Ocean and(Figure 2.1.3). By the mid-21st century, annual riverparts of the North Atlantic Ocean (Figure 2.1.2),

runoﬀ and water availability is projected to increase incontinuing recent observed trends; contraction of

the high latitudes (and in some tropical wet areas)snow cover area, increased thaw depth over mostand decrease in some dry regions in the mid-latitudes

permafrost regions, and reduced sea ice extent; a very

and tropics. There is also high conﬁdence that many

likely increase in the frequency of hot extremes, heatsemi-arid areas (e.g. the Mediterranean basin, thewaves and heavy precipitation; a likely increase inwestern United States, southern Africa and northern

tropical cyclone intensity, poleward shift of extra-

Brazil) will suﬀer a decrease in water resources due totropical storm tracks with consequent changes inclimate change.

winds, precipitation and temperature patterns; a very

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5（℃）
Figure 2.1.2 Projected surface temperature changes in 2090-2099 relative to 1980-1999 for the SRESA1B scenario.

％
-20

-10

-5

5

10

20

Figure 2.1.3 Relative changes in precipitation for the period 2090-2099 relative to 1980-1999, basedon the SRES A1B scenario for December to February (left) and June to August (right).

15

Part II Global Warming Projections

Chapter 2. Projection around Japan

How will the climate of Japan change as a result ofResearch

Institutedeveloped

theCoupledglobal warming? To develop adaptation measures for

Atmosphere-Ocean Regional Climate Model (CRCM)

such warming, regional climate projection is essential.

to project the climate peculiar to Japan, andIn Japan, climate conditions vary regionally due to the

conducted climatic projection at the end of the 21st

country s unique topographical characteristics andcentury for the IPCC A1B and B1 scenarios (seevarious atmospheric phenomena including monsoons,

Chapter 1 of Part II).

cyclonesandtyphoons.

JMA s

130°

Meteorological

140°

130°

4.0

40°
40°

30°

4.0

40°
40°

3.5

3.0

2.5

2.5

2.0

2.0

1.5

1.5
1.0

30°
30°

0.5
0.0

130°

3.5

3.0

1.0

30°

140°

0.5
0.0

140°

130°

140°

Figure 2.2.1 Projected surface temperature changes (°C) in winter (December to March) for the period
2081-2100 relative to 1981-2000 for the A1B scenario (left) and B1 (right).

130°

130°

140°

140°

40°

40°

40°

40°

30°

30°

30°

30°

130°
-300

-200

130°

140°
-100

0

100

mm
200

-300

-200

140°
-100

0

100

mm
200

Figure 2.2.2 Projected snowfall changes converted to precipitation (mm) in winter (December to March)
for the period 2081-2100 relative to 1981-2000 for the A1B scenario (left) and B1 (right).

16

Part II Global Warming Projections

Chapter 2. Projection around Japan

Projections of average temperature and snowfall in

rainfall is expected to increase because of warming.

winter (December to March) are shown in Figures

In contrast, snowfall in Hokkaido (the island to the2.2.1 and 2.2.2.

north of the main island) is projected to rise due toTemperatures at the end of the 21st century

increased water vapor in the atmosphere.

relative to the present are projected to increase by

A projection of sea surface temperatures around

1.5 to 3°
C for the A1B scenario and by 1 to 2°
C for theJapan is shown in Figure 2.2.3. In the Sea of Japan,

B1 scenario. Warming is expected to be the greatest

warming is expected to be higher than that in any

at higher latitudes.

other area. Figure 2.2.4 shows how much the sea

Snowfall in the Tohoku district (the northern part oflevel is projected to rise.

Japan s main island) is projected to decrease, while

50°
N

50°
N

A1B

B1

40°
N

40°
N

30°
N

30°
N

20°
N
120°
E

130°
E

140°
E

150°
E

20°
N
120°
E

130°
E

140°
E

150°
E

Figure 2.2.3 Projected linear trends of annual sea surface temperatures (°C per century) from 1981 to
2100 for the A1B scenario (left) and B1 (right).

50°
N

50°
N

40°
N

40°
N

30°
N

30°
N

20°
N
120°
E

130°
E

140°
E

150°
E

20°
N
120°
E

130°
E

140°
E

150°
E

Figure 2.2.4 Projected linear trends of annual sea level rises (cm per century) from 1981 to 2100 for
the A1B scenario (left) and B1 (right). [*] denotes that the value is not signiﬁcant, while the uncertaintyof values marked with [ ] is large. Contributions from melting glaciers and ice caps are not included inthis projection.

17

Part III JMA s Eﬀorts for Monitoring
Chapter 1. Ocean Observation and the Argo Project

The ocean plays an important role in climate variabil-

Five JMA research vessels operate in the western

ity and change by releasing and absorbing large

North Paciﬁc including the seas in the vicinity ofamounts of heat and carbon. In order to monitor ocean

Japan. These vessels mainly monitor large-scale,and climate changes, JMA conducts oceanographic

long-term oceanic variations such as seawaterobservations using research vessels, proﬁling ﬂoats,

temperature, salinity, ocean currents and biogeo-

tidal stations, voluntary observing ships and earth-chemical components. They also observe elements

observing satellites.

relevant to the marine environment, such as heavy
metals, pollutants, concentration of CO2 and othergreenhouse gases both in seawater and in the air
over the ocean.

50°
N

JMA participates in the Argo project, which is
conducted through an international cooperation of
meteorological and oceanographic organizations. In
this project, proﬁling units called Argo

40°
N

floats are

deployed to observe water temperature and salinityfrom the sea surface to a depth of 2,000 meters.
30°
N

JMA operates the Japan Argo Data Assembly Centerto collect and distribute the data for international
exchange.

20°
N

JMA observes sea levels at tidal stations locatedalong the Japanese coast to monitor sea level rises
related to global warming.

10°
N

0°

10°
S
120°
E

130°
E

140°
E

150°
E

160°
E

170°
E

180°
E

Figure 3.1.1 Map of major surface currents (redand blue lines with arrows) and routine observationlines of JMA research vessels (yellow lines)

Picture 3.1.1
JMA s Ryofu Maru research vessel

18

Picture 3.1.2
Ryofu Maru crew members deploy an Argo ﬂoat.

and Projection of Climate ChangePart III JMA s Eﬀorts for Monitoring
Chapter 1. Ocean Observation and the Argo Project

and Projection of Climate Change
Chapter 2. World Data Centre for Greenhouse Gases (WDCGG)

JMA operates the World Data Centre for Green-

zonally

averagedlatitudinal

distributionofhouse Gases (WDCGG) under the WMO s programme

atmospheric CO2 concentrations (Figure 3.2.3). It

on the monitoring of greenhouse gases. The WDCGG

shows that concentrations in mid- and high latitudes

gathers and archives measurement data on green-in the Northern Hemisphere increase faster thanhouse gases from all over the world (Figure 3.2.1), andthose in the Southern Hemisphere because of large

provides analyses using these data. The analyses of

CO2 emissions from human activities in the Northern

the WDCGG are adopted as basic materials in WMO

Hemisphere. It also indicates that seasonal variations

Greenhouse Gas Bulletins (Figure 3.2.2), and are alsoin CO2 concentrations are larger in the Northern

used in the IPCC AR4.

Hemisphere than in the Southern Hemisphere

One of the analyses of the WDCGG is a threedimensional representation of annual variations in

because of the large inﬂuence of absorption by
forests in the north.

WMO World Data Centre for Greenhouse Gases

Ground-based

Aircraft

Sips

Figure 3.2.1 The WMOʼs CO2 monitoring network

Figure 3.2.2
Bulletin

WMO Greenhouse Gas

Figure 3.2.3 Three-dimensional representation of annual variations in zonally averaged atmospheric CO2 distribution. This
analysis was performed using data archived by the WDCGG.

19

Part III JMA s Eﬀorts for Monitoring and Projection of Climate Change

Chapter 3 Asia s First Long-Term Atmospheric Reanalysis

Reanalysis is the process of analyzing the state of

to 2004, and archives more than 100 meteorologicalpast weather using all observational data possible

variables (such as air temperature and wind) with

with the latest technology. The Japan Meteorologicalconsistent and high quality.

Agency and the Central Research Institute of ElectricJRA-25 data and products are widely used forPower Industry jointly executed the Japanese 25-year

research on meteorology and climatology, as well as

Reanalysis (JRA-25) project, the ﬁrst of its kind infor operational climate monitoring and seasonal

Asia.

forecasting.

The JRA-25 covers the 26-year period from 1979

Annual mean
mm/day
35
29
23
17
13
10
8
6
4
2
1
0.2

60N
30N
EQ
30S
60S

0

60E

120E

180

120W

60W

Figure 3.3.1 Distribution of annually averaged daily precipitation (mm/day)

Annual mean
W/m2
300
275
250
225
200
175
150
125
100
80
60
50
40
30
20
10

60N
30N
EQ
30S
60S

0

60E

120E

180

120W

60W

Figure 3.3.2 Distribution of annually averaged net surface solar radiation (W/m2).
This distribution is expected to be used in identifying appropriate regions for solar power generation.

20

Part III JMA s Eﬀorts for Monitoring and Projection of Climate Change

Chapter 3 Asia s First Long-Term Atmospheric Reanalysis

Chapter 4. Establishment of an Advisory Panel on
Extreme Climate Events
Based on operational climate system monitoring,
JMA has provided information on extreme climate
events, such as the heat waves of 2004 and heavy
snow in 2005/06.
In order to improve such information by enhancing

to extreme climate events, including their causes
and mechanisms
3) Recommendations on the application of resultsfrom climatological research on extreme climate
events to JMA s services and activities

cooperation with the research community and utilizing

When an extreme climate event occurs or is likely tothe outcome of recent research on extreme climate

occur, the panel immediately initiates analysis andevents, JMA established the Advisory Panel on

examination of the event s causes to provide

Extreme Climate Events, consisting of 10 prominentscientiﬁc advice to JMA. Based on the advice of theexperts from universities and research institutes, inpanel and other relevant information, JMA issues

June 2007.

statements including the causes of and outlook for

The missions of the panel are as follows:
1) Climatological analysis and research on extreme
climate events
2) Advice on information that JMA prepares in regard

such events. These statements are provided todecision makers in various sectors as well as to thegeneral public to help them avoid or minimize theadverse eﬀects of extreme climate events.

Figure 3.4.1 Activities related to the Advisory Panel on Extreme Climate Events

21

Part III JMA s Eﬀorts for Monitoring and Projection of Climate Change

Chapter 5. Tokyo Climate Center (TCC)

JMA established the Tokyo Climate Center (TCC) in

The center also places focus on technical transfer

April 2002 with the main purpose of promoting theand capacity-building activities.

application of climate information in the mitigation ofservices, TCC has conducted training sessions on

As part of suchdisasters due to extreme climate events, as well as

the application of climate information for prospective

the planning of agricultural production and water

NMHS staﬀ members through the Japan International

resource management in Asia and the Paciﬁc region.

Cooperation Agency (JICA). Over the last 5 years, 42

TCC mainly provides National Meteorological andparticipants from 34 countries have attended theHydrological Services (NMHSs) in Asia and the Paciﬁctraining.

region with information on global extreme climate

forecasting is also conducted by TCC.

On-site technical training in seasonal

events, atmospheric and oceanic conditions, numeri-

These activities are in line with the Regionalcal prediction data for seasonal forecasts, El Niño

Climate Center (RCC) s concept, which is in themonitoring and prediction, and global warming projec-

process of formal approval by WMO.

tion.

Provision of Information on Climate
Monitoring and Prediction

Tokyo Climate Center

Provision of climate information
・Data for seasonal forecasts
・El Niño monitoring and prediction
・Global extreme climate monitoring
・Global climate system monitoring
・Global warming projection
Capacity building
・Training on application of climate
information in NMHSs- Assistance in climate services in each country- Promotion of application of climate information

Workshops and International Meetings

TCC homepage
http://ds.data.jma.go.jp/tcc/tcc/index.html

NMHSs in Asia andthe Paciﬁc region

Application ofclimate informationin each country

Preparation andprovision of climate
information- Mitigation of disasters
related to extreme
climate events- Planning of agricultural
production- Water resource
management

Figure 3.5.1 TCCʼs activities at a glance.

22

Part III JMA s Eﬀorts for Monitoring and Projection of Climate Change

Chapter 5. Tokyo Climate Center (TCC)

Chapter 6. Research and Development for
Global Warming Projection Information
The Meteorological Research Institute (MRI) carried

In this research project, MRI develops a cloud-out climate change projection using the MRI global

resolving regional climate model that explicitly treats

climate model with a mesh of about 280 km. The

clouds with a 4-km mesh, and can reﬂect Japan s

results made an important contribution to the IPCC

detailed orography in projecting small-scale phenom-

AR4, and were also utilized to drive the MRI regionalena such as heavy rainfall and the frequency ofclimate model (RCM) with a 20-km mesh to project

extreme events.

climate change in Japan. Information on regional

MRI is developing the MRI Earth System Modelclimate changes in Japan for temperature, precipita-(MRI-ESM) with the aim of reducing the uncertainty oftion, etc. are presented for several climatologicalglobal warming projection. Based on a state-of-the-art

regions (such as North Japan, East Japan and Westglobal climate model, carbon cycle processes on land

Japan), each of which is subdivided into the Sea ofand in oceans, sources and transport of aerosols, andJapan side and the Paciﬁc side as appropriate.

chemical reactions of trace gases including ozone

Since global warming is now unequivocal, moreare modeled and integrated into the earth system

detailed and accurate projection is demanded frommodel. The model also deals with changes in ice

various sectors such as those dealing with water

sheets, an important factor aﬀecting sea level

resources, disaster prevention, agriculture, forestry

variations.

and human health, for the purpose of promotingThis project is expected to contribute to promoting

adaptation and mitigation measures. To respond toadaptation to and mitigation of global warming inthese requests, MRI launched a ﬁve-year research

Japan. It will do so by providing more detailed andproject called Comprehensive Projection of Climate

reliable climate change information as a sophisti-

Change around Japan due to the Global Warming

cated regional climate model that uses projection by(Figure 3.6.1) in FY 2005.

the earth system model as its boundary conditions.

Figure 3.6.1 Schematic chart of the Comprehensive Projection of Climate Change around Japan due tothe Global Warming research project23

Climate Change Present and Future

2008

April 2008

Japan Meteorological Agency