Kịch bản biến đổi khí hậu và nước biển dâng cho Việt Nam trong tương lai

CHINH SACH VA QUAN LY

KICH BAN BIEN DOI K H I HAU VA N VOC BIEN DAN6
CHO VIET NAN f RONC f V0N6 LAI
•

Tran Thuc, Nguyen Van Thang, Huynh Thi Lan Hi/dng,
Mai v i n Khiem, Nguyen Xuan Hien, Doan Hi Phong
Vi^n Khoa hgc Khf tUflng Thuy vdn vd Bi^n ddi khi hju

Kjch biin bien doi khi hau (BDKH) va nifdc bien dang cho Viet Nam
trong ti/dng lai mdi di/dc Vien Khoa hoc Khi tifdng Thuy van va
BDKH hoan thien. Kich b^n cung cap thong tin mdi nhat ve nhQng
bieu hien, xu the bien ddi cua l(hi' hau trong qua khufva diTtinh khi
hau va nUdc bien dang trong the ky XXI6 Viet Nam. Day ia dQlieu
quan trong, la cd sd djnh hUdng cho cac bo, nganh, dja phUdng
danh gia tac dong tiem tang cua BDKH, xay diing va trien khai ke
hoach ifng pho hieu qud vdi BDKH va nUdc bien dang. DUdi day la
nhQng thong tin chinh cua Kjch bin.
Phuuni phap khoa hoc trmg xAv
««nigKlchbin
So vdi Kjch bdn BDKH vd nudc
biln ddng da dupc xdy dyng trudc
dd (2012), Kjch bdn mdi sil dyng
s l Iidu khi tupng thdy vdn cOa
150 trgm quan trie trdn ddt liln
vd hdi ddo, s l Iidu myc nude biln
ciia 17 trgm hdi vdn vd myc nude
biln do dgc tU vd tinh, dupc cdp
nhdt d i n nam 2014. S I Iidu dja
hinh bdn d l ty Id 1:2.000,1:5.000

vd 1:10.000 do dgc bdi cdc dy dn
thudc ChUPng trinh mye tidu quoc
gia Ung phd vdi BOKH, dupc cdp
nhdt din thdng 3/2016. D l xdy
dyng Kjch bdn, cdc nhd nghidn
cUu da ap dyng phuong phdp
ehl tiet hda ddng lyc d l tinh toan
xdy dyng kjch bdn BDKH. 5 md
hinh khf hau toan cdu va khu vyc
dd phan gidi cao dupe dp dyng:
AGCM/MRI (Nhat Bdn), PRECIS
(Anh), CCAM (Oc). RegCM (Y) va

10

clWRF (My). Phyong phdp thing
kd dupc diing d l hidu chinh kit
qud ciia md hinh ddng lyc theo
s l Iidu thyc do tgi cdc trgm quan
trdc nhdm phdn anh dilu kidn dja
phuong vd gidm sai s l hd thing
eiia md hinh.
Kjch bdn ning dd khf nha kinh
tidp cdn kjch bdn mdi nhdt v l
phat thdi hay dUdng ning dd khf
nha kfnh dgi didn 'Representative
Concentration Pathways RCP)
dupc diing trong Bao cdo danh
gid Idn thU 5 (ARS) eua Uy ban
lidn chfnh phu v l BDKH (IPCC).

Kjch bdn RCP ehil trpng d i n
ning dd khf nha kfnh thay vi cdc
qua trinh phat thdi trdn cP sd cac
gid djnh v l phat triln ciia kinh t l xd hdi. cdng nghd, ddn s l . . . RCP
dua ra gid djnh v l dich d i n d l
t h l gidi ed nhilu lya chpn trong
qud trinh phat triln kinh t l , cdng
nghd, ddn so... Cd 4 kich bdn.

BSJKrtfeNam ^""<=-2o,6

gIm: RCP2.6, RCP4.5, RCP6.0,
RCP8.5.
Kjch bdn nudc biln ddng dUpc
xdy dyng theo cdc nghidn cilu
mdi nhdt cua IPCC cd tham khdo
kjch bdn eua cac nudc nhu Uc,
Hd Lan, Singapore. Myc nUdc
ddng ting d n g tgi mdt khu vi/c
dupc xdc djnh Id ting ciia cdc
thdnh phdn: gian nd nhiet vd
ddng lyc; tan bdng cua cac sdng
bang, niii bdng trdn lye dia; cdn
bdng khii lupng b l mdt bdng d
Greenland; cdn bdng khii lUdng
b l mdt bdng d Nam cijc; ddng
li^c bdng d Greenland; d$ng li,/c
bdng d Nam eye; thay d l l lUdng
trO nudc trdn lyc dja; dilu chinh
ddng ttnh bdng.

Cac k i t qud ndy dUpc ehilt
xudt cho cdc khodng thdi gian:
tUdng lai gdn (2016-2035), tuong
lai Vila (2046-2065), tUPng lai xa
(2080-2099).


CHINH SACH VA QUAN LY

MMHHI

I aMM DMi cia Uch Lupng mua 1 ngay Idn nhdt trung

d ddy, chiing tdi gidi thieu
2 kjch bdn chfnh: RCP4.5 (kha
ndng de xdy ra nhat) va RCP8.5
(ft khd ndng xdy ra, nhung n l u
xdy ra se gdy tac ddng Idn nhat).
V6 nhi$t dg: nhiet dp d tat
cd cdc vCing ciia Vidt Nam deu ed
xu t h l tdng so vdi trung binh thdi
ky cd sd (1986-2005), mile tdng
ldn nhdt la d khu vuc phfa Bdc.
Theo kich bdn RCP4.5, den cuoi
t h l ky XXI, d phfa Bdc nhidt dp
tdng chii y l u tU 1,9+2,4°C va d
phfa Nam tU 1,7-^1,9°C so vdi thdi
ky cd sd. Nhidt dp thap nhdt trung
vd cao nhdt trung binh cd xu
t h l tang ro rdt. Theo kich bdn

RCP8.5, d i n culi t h l ky, nhidt dp
d phia Bdc tdng tU 3,3H4,0°C va d
phia Nam tU 3,0+3,5°C so vdi thdi
ky CO sd (hinh 1).

binh cd xu the tang tren toan
lanh tho Viet Nam vdi mile tdng
p h i biln tu 10-^70% so vdi trung
binh thdi ky cd sd. Theo kjch ban
RCP8.5, mile tang nhilu nhat cd
the tren 20% d hau het Bae Bp,
Trung Trung Bd, mpt phdn Nam
Bp va Tay Nguydn (hinh 2).

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; • ;

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• S : .-

;iillll|
r

Ill

ddo Hoang Sa va TrUdng Sa vdi
gia tri tUdng Ung la 58 cm (36-^80
cm) va 57 cm (33-e^3 cm); khu
vUc Ca Mau - Kidn Giang la 55
cm (33-78 cm); khu vi/c Mdng
Cai
Hdn Dau va Hdn Dau
Deo Ngang cd mUc nUdc bien
dang thdp nhat Id 53 cm (32^75
cm). Theo kjch bdn RCP8.5,
muc nudc bien dang cao nhdt is
khu vyc qudn ddo Hoang Sa va
Trudng Sa vdi gia tri tUPng Ung
la 78 cm (52-5-107 cm) va 77 em
(50-1-107 cm); khu v\fc Ca Mau
Kien Giang la 75 cm (52-^106
cm); khu vyc Mdng Cai
Hdn
Ddu, Hdn Dau Deo Ngang ed
muc nudc biln ddng thap nhdt la
72 cm (49+101 cm).

lIlMlll
Hinh 2: kich bin It/gng mua (%)

Gid mua vi mdt sd hi$n
tupng khi h$u ci/c doan: sd

lupng bao y l u vd trung binh cd
xu t h l gidm nhe hode it thay doi,
nhung bao mgnh d i n rat mgnh cd
xu t h l gia tdng. Gid miia miia he
khu vyc Ddng A (trong dd ed Viet
Nam) bdt ddu sdm hpn, ngay kit
thiic mudn hpn hode ft thay d i i .
Mua cyc doan trong thdi ky hogt
ddng eiia gid mua miia he ed khd
ndng tdng. SS ngay ret dam, ret
h^i d cae tinh mien nui phia Bdc,
Oing bdng Bdc Bd, Bdc Trung
Hinh 1: kich bin nhi$l dg fC)
Bd diu gidm. So ngay ndng nong
Vd lupng miia: lupng mUa ( s l ngay cd nhidt dp cao nhat Tx
ndm cd xu t h l tdng trdn phgm vi > 35°C) ed xu t h l tang trdn phdn
toan qu6c so vdi trung binh thdi Idn ed nudc, Idn nhdt la d Bdc
ky CO sd. Theo kich bdn RCP4.5, Trung Bd. Han hin ed t h l trd ndn
d i n culi t h l ky XXI, lupng mUa khdc nghidt hdn d mdt s l viing do
ndm cd mUe tdng p h i biln tU nhiet dp tang va khd ndng gidm
5^15%. Mdt s l tinh ven biln lupng mua trong miia khd.
Ddng bdng Bdc BO, Bdc Trung
Bd, Trung Trung Bd ed t h l tang
- Mtfc nt/dc bien ddng: theo
trdn 20%. Lupng mUa mua khd kich bin RCP4.5, mile nude biln
d mdt s l viing cd xu t h l gidm. ddng cao nhat d khu vyc qudn

Hinh 3: kich bin ni/dc biSn ding

• Nguy cd ng$p do nUdc biin

dang: n l u nude biln ddng 100
em, khodng 16,0% didn tich Dong
bdng sdng Hing, 1,5% didn tich
cac tinh ven biln miln Trung
tu Thanh Hda d i n Binh Thudn,
17,8% didn tfch TP H i Chi Minh,
38,9% didn tfch Ding bdng sdng
Cilu Long cd nguy cd bj ngdp.
Cym ddo Vdn D i n , Cdn Ddo va
Phil QuIc cd nguy cd ngdp cao.
Nguy CP ngdp d l l vdi qudn ddo
Trudng Sa la khdng Idn. Qudn
ddo Hodng Sa cd nguy cd ngdp
Idn hdn, nhdt la d l l vdi cdc ddo
thude nhdm Ludi Lilm va ddo Tri
Tdn (hinh 4).

36 11 nam 2016 HOA HOC
NGHi

\feNam

\


CHINH SACH VA QUAN LY
dupc ap dyng d i i vdi cdc tidu
chuln thilt k l cho cac cdng tnnh
mang tinh khdng Idu ddi va cac
quy hoach, k l hogch ngdn hgn.

Kjch bdn RCP8.5 cdn dUi?c dp
dyng cho cac cdng trinh mang
tinh vTnh ciiu, ckc quy hogch, k l
hogch dai han.

(c)

(a)
Hinh 4: nguy ca ng0p Ong vdi m\fc nt/dc biSn ddng 100 cm, trong <36: (a) Ven biSn
Vi^t Nam: (b) Ddng biuig sdng Hdng vd Quing Ninh; (c) Ddng bdng sdng CCfu Long

•#1 l i khayta PiM khi sir MM

1) Vide sil dyng Kjch bdn cdn
li/a ehpn phii hpp vdi tUng nganh,
ITnh vyc va dja phydng vdi cdc
tidu chi: tinh ddc thu (ciia ngdnh,
Unh vyc, dja phydng_); da mye
tidu: hidu qud nhilu mdt (kinh t l ,
xd hdi, mdi trydng); bin vQng;
khd thi, khd ndng ling ghdp vdi
cdc chiln lypc, chtnh sach vd k l
hogch phdt triln.
2) Khi dp dyng kjch bdn cho
dja phydng, cdc byde sau ddy
dupc khuyin nghj: xac djnh ckc
thdng s l khi hdu quan trpng d l l
vdi ngdnh vd dll tupng nghidn
eUu phu hpp vdi dja phudng;

chpn kjch bdn cho dja phudng tU
kjch bdn quIc gia; siir dyng cdc
cdng cy tinh todn vd phdn tich d l
xdc djnh nhi/ng thdng tin quan
trpng nhu sy thay d l l c h i dd

ddng chdy, ngdp lyt, xdm nhdp
mdn, nyde ddng do bao, biln d l l
dudng bd_
3) Vide triln khai, xdy dung vd
thye hidn cdc gidi phdp Ung phd
vdi BDKH khdng nhdt thilt phdi
tiln hanh dgi tra d quy md t h l ky,
ma cdn cd sy phdn ky thye hidn;
cdn xdc djnh mUc dd Uu tidn di/a
trdn nhu cdu thyc tiln, nguIn lyc
cd dupc trong tUng giai dogn d l
lya chpn kjch bdn phii hpp nhdt.
4) Theo Hidp djnh Paris v l
BDKH, tdt ed cdc quie gia phdi
hdnh ddng d l giO cho nhidt dd
todn cdu vao culi t h l ky tang d
mdc dudi 2°C so vdi thdi ky tiln
cdng nghidp. Dilu ndy cd nghTa
kjch bdn RCP4.5 ed nhilu khd
nang xdy ra hdn so vdi cae kich
bdn RCP khdc.
5) Kjch bdn RCP4.5 cd t h l

SSISiVietNani ^'"^-^^^

6) Kjch bdn BDKH va nudc
biln dang ludn ton tgi nhiing
dilm chua chdc chan vi cdn phy
thudc vdo kjch bdn phdt thdi khi
nha kinh, nhOng hiiu bilt cdn
hgn che v l hd thing khi hdu, qud
trinh tan bdng, phUdng phdp vd
md hinh tinh toan... Do dd, khi
sLi dyng kjch bdn trong danh gid
tdc ddng ciia BDKH, cdn xem xdt
mpi khd ndng cd t h l xdy ra ciia
khf hdu tUdng lai.
7) Md hinh khi hdu dang dUpc
tilp tyc phdt triln d l ndng cao
mifc dd chdc chdn cua kit qud
tfnh todn. Vi t h l , kjch bdn BDKH
vd nudc biln ddng cdn dUde tilp
tyc cdp nhdt theo Id trinh ciia
IPCCej

Til II0U nam khia
1. BO T4i nguySn v4 M6i Iradng (2009,
2012, 2016 (dV thSo)), Kich bin BDKH vi
nudc biSn ding cho Viit Nam.
2. IPCC (2013), Cliitiale Change 2013:
The Physical Science Basis. Contribution
of Worl(ing Group I lo the Fifth Assessment
Report of the IPCC.