Cập nhật kịch bản biến đổi khí hậu và nước biển dâng cho Việt Nam

Nghien cufu - Trao doi

V Cap nliat i(ich ban bien doi Ichi hau va
nirdfc bien dang cho Viet Nam
O TRAN THUC NGUYEN VAN THANG, HUYNH TH! LAN HUONG,
MAI VAN KHIEM, N G U Y I N XUAN HliN, DOAN HA PHONG
Vien Khoa hgc KhitOpng ThOy van vi Biin ddi khlh$u

K

jch ban BDKH&NBD cho Viet Nam mdi nha't dupc c$p nhit theo id
trinh da dupc xic dfnh trong Chiin lupc qudc gia ve BDKH, nhim
cung cap nhiing thdng tin mdi nhat ve bleu hign, xu thi biin doi trang
qui khd va kich bin BDKH&NBD trong Thi ky21 d Vigt Nam.

Kich bdn dupe xdy dpng dpa
tren cd sfl sau: Bao cdo ddnh gid
lan thuf 5 (AR5) cDa Ban Lien
ehfnh phii v l BDKH (IPCC); sd
Ii0u KTTV dupe cdp nhdt den
nam 2014; xu the bien BDKH,
NBDflVidt Nam; cdc md hinh khi
hdu todn d u vd md hinh khf hdu
Khu vuc dd phan gidi cao cho khu
vpc Vidt Nam, ede md hinh khi
quyln - dgi dUdng; cac nghidn
cdu cCia Vien Khoa hpc
KTTV&BDKH, Hdi ddng tU v i n
cDa Uy ban Qudc gia v l BDKH,
cac Vidn nghidn cijfu va truflng
Dgi hpc ciia Vidt Nam. Thdng tin

kjch bdn dupc cung d p bao gdm:
Nhipt dd, mua (ndm, mua), cpc
doan khf h^u (bao, gid mua, ning
ndng, ret dgm ret hgi, ban hdn),
mpc NBD ddi vfli cdc tlnh ven
bien vd hdi ddo, nguy ed ngap
Cfng vdi cdc mute NBD. Cac
khodng thdi gian cCia T h i kjf 21
dupe xet d i n , bao gdm: Dlu t h i
k^ (tUdng lai gan, 2016 - 2035),
giiJfa T h i k^ (tUdng lai vPa, 2046
- 2065), vd cudi T h i kjf (tUdng lai
xa. 2080 - 2099).

Kjch bdn bien ddi khi hgu va
nifdc bien dang cho Vi#t Nam
Kieh bim ndng dd khf nha kfnh:
Cdch tilp cdn mfli v l kjch bdn phat
thdi Id kjch bdn phdt thdi chuin
(Benchmark emissions scenarios)
hay dudng ndng dd khf nhd kfnh
dgi didn "Representative Concentration Pathways - RCP) da dUpc
dCing trong AR5 c&a IPCC.
Kjch bdn RCP chu trpng din
ndng dd khf nhd kfnh chi2 khdng
phdi cdc qua trinh phdt thdi trdn
cd sfl cdc gid djnh v l phdt triln
cOa KT-XH, cdng nghd, ddn so,...
RCP dua ra gid djnh ve dfch den
d l the gidi cd nhilu Ipa ehpn

trong qud trlnh phat triln kinh t l ,
edng nghd, dan sd,„. Cd 4 kich
bdn, gdm: RCP2.6, RCP4.5,
RCP6.0, va RCP8.5 (Hinh 1).
Sd lieu dupc sd dung: So lidu
dOng trong tfnh toan dupe c^p
nhdt dd'n ndm 2014, bao gdm: Sd
lidu KTTV cDa 150 trgm quan trie
trdn dat liln va hdi ddo; sd li^u
mpc nude bien eua 17 trgm hdi
vdn ven biln va hdi ddo; sd li$u

mpc nudc biln do dgc tiS ve tinh;
sd lidu dja hinh bdn dd ty Id
1:2.000, 1:5.000 va 1:10.000
dupc do dae bfli cac dp an thudc
ChUdng trtnh mye tidu quoc gia
dng phd vdi BDKH.
Phuang phip: PhUdng phdp
ehi tilt hda ddng ipc dupe dp dyng
d l tfnh toan xdy dpng kjch bdn
BDKH. Nam md hinh khf hdu todn
eau vd khu vpc dupc dp dyng. Mdi
md hinh cd cac phUdng dn tfnh
todn khde nhau dpa tren ket qud
tis md hinh toan eau (IPCC, 2013).
Tdng cdng cd 16 phUdng dn tfnh
todn. PhUdng phdp thdng kd dupe
dp dpng d l hidu ehinh ket qud
cua cdc md hinh ddng Ipc theo sd

Hinh 1.

ViaydSamgixicbdcx^

^.f^^^^^^^^^

Tdi nguyen vd Mdi tru'dng | KH-Thing 1/2016


lieu thpe do tai cde trgm quan trae
nham phan dnh dieu kien ep the
cua dja phUdng va gidm sai sd he
thdng eua md hinh.
Kjch bdn NBD dUpc xdy dpng
theo edc nghidn ciiu mdi nhat
cua IPCC va tham khdo kjch ban
eua ede nudc nhU: Ue, Ha Lan,
Singapore. Mpc nUde dang tong
cpng tgi mpt khu vpc dupe xac
djnh la tdng eua edc thanh phan,
bao gom: Gian nfl nhiet va ddng
lUe; tan bang cua cac sdng bang,
nui bang tren Ipc dja; can bang
khd'i lupng be mat bang 6 Greenland; cdn bang khd'i lupng be mat
bdng 6 Nam Cpc; ddng lye bdng
d Greenland; Ddng Ipc bang 6 Nam
cue; thay dli lupng trO nUdc trdn
luc dja; dieu ch?nh dang tTnh bang.

Hinh 2. Kich bin nhiet dd (oC)

^ A
^ \0
-^'

Hinh 3. Kich bin lupng mda (%)

•-*•

L1>^'
-J - - n

!—-^
—"—Jlf

Hinh 4. Kich ban mi/c nUdc biin dang

M0t sd kit qua chinh
Kjch ban BDKH cho Vidt
Nam ed the dupe tdm tat nhU sau:
Nhiet do trung binh: Nhiet dp
trung binh ndm, mua (ddng, xuan,
he, thu) 6 tat cd cde vung cua Viet
Nam dlu ed xu the tdng. Theo
kjch ban RCP4.5, den eudi The
ky, d phia Bic nhidt dp tang phd
bien ti^ 1,9 •=• 2,4°C va S phfa Nam
td 1,7 V 1,9''C. Nhiet dp epe trj ed
xu t h i tang rd rdt (Hinh 2).
Nhiet do cUc tn: Nhiet dp cue

trj ed xu the tdng so vdi trung binh
thdi ky 1986-2005 b tat ea cae
vung. Den eudi the kf, theo kich
bdn RCP4.5 nhiet dp tdi eao trung
binh nam tang 1,7 -;- 2,7°C, eao
nhat la Ddng Bae, Dong Bang
Bdc Bd, thap nhd't la Nam Trung
Bd va Nam Bd. Nhiet dp tdi thap
trung binh ndm tang 1,8 •;- 2,2''C.

LUdng mUa nam vi mUa cUc
tri: Lupng mUa ndm ed xu the bdn RCP4.5 lupng mua ndm tang 20%. Theo kjch bdn RCP8.5,
tdng so vdi thdi ky ed sfl, lupng d hau hit ca nUde, phd bien tU 5 mdc tang nhilu nhat cd the trdn
mUa mua khd fl mdt sd vung ed •r 15%; mdt sd tfnh ven bien Ddng 20% d hau het dien tfeh Bac B6,
xu thi giam. Mua cue trj cd xu the bang Bae Bd, Bde Trung Bd, Trung Trung Bd, mdt phin Nam
tang. Dd'n cudi The ky, theo kieh Trung Trung Bd cd the tang trdn Bd va Tdy Nguyen (Hinh 3).
10

Tdi nguyen vd Mdi trudng | Ky 2-Thing4/2016


Mgt sd hien tupng khi hiu a/c
doan: So lupng bao vd dp thap
nhidt dfli trung binh cd xu t h i
gidm nhp hoae it thay doi nhung
bao mgnh ed xu the gia tdng. Gid
mua miia he bat d l u sdm hdn.
Sd ngdy ret ddm, ret hai 5 cac
t?nh miln phia Bae gidm. Sd ngdy
nang ndng cd xu t h i tang d phan

Idn cd nude, Idn nhat la fl Ble
Trung Bd. Han hdn trd nen khac
nghiet hdn fl mdt sd vung do nhiet
dd tang va IUdng mUa giam trong
miia khd.
MOc nUdc biin ding: Vdo cuoi
the ky, theo kjch bdn RCP4.5 mpc
nude biln dang cao nhlt fl Wnu vpe
quan ddo Hoang Sa vd Trudng Sa;
58em (33 em -r 83 cm); thap nhat
fl khu vpc Mdng Cdi dd'n Hdn Dau:
53cm (32 cm -^ 75 cm). Theo kjch
ban RCP8.5, mpc NBD cao nhlt 6
khu vpc quin ddo Hodng Sa,
TrUdng Sa: 78 cm (52 em v 107
em); ttilp nhat d khu vpc Mdng Cdi
den Hdn Ddu: 72 cm {49 cm ^ 101
cm) (Hinh 4).

Hinh 5. Nguy cd ngap Ong vdi mOc node biin dang 100 cm
a) Ven biln Viet Nam; b) DB sdng Hdng va Qudng Ninh;
c) DB sdng C&u Long

khdng nhd't thilt phdi tiln hanh
dai tra d quy md T h i kf, ma phdi
cd su phdn ky thpc hidn; can xac
djnh dupe mUe dd Uu tien dpa
tren nhu eau thUe tien, ngudn Ipc
cd dupc trong tPng giai doan d l
lua ehpn kjch bdn phu hpp nhat.

Hdi nghj todn d u ve BDKH nam
Nlu NBD Im, khoang 16,0% 2015 da thanh edng vdi viee
didn tfeh DB sdng Hdng; 4,8% dien thdng qua Hidp djnh Paris ve khi
tich tinh Qudng Ninh; 1,5% didn hdu. T i t cd cac qud'c gia trdn the
tfeh cde tinh ven bien mien Trung gidi deu thdng nhd't hanh dpng de
tis Thanh Hda den Binh Thudn; giO eho nhiet dp toan cau vdo
17,8% di$n tfeh TP. Hd Chi Minh; cudi the ky tdng fl dUdi mdc 2°C
4,8% didn tich Ba Rja - Vung Tdu; so vdi thdi ky tien cdng nghiep.
40% didn tich DB sdng CCfu Long Dilu nay ed nghTa la kjch ban
ed nguy ed ngdp (Hinh 4).
RCP4.5 rat cd nhilu khd ndng
Cac dao ed nguy cd ngdp xdy ra hdn so vdi cac kjch bdn
cao nhlt la eym dao Van Ddn, RCP khdc. Vi vdy, kjch ban
Cdn Ddo va Phii Qudc. Nguy cd RCP4.5 cd the dUpe dp dpng ddi
ngdp ddi vdi nhu'ng ddo thude vdi ede tidu ehuan thilt k l eho
quan ddo Trudng Sa la khdng cdc cdng trinh mang tfnh khdng
Idn. Cpm ddo Hoang Sa ed nguy Idu ddi va cac quy hoach, ke
cd ngdp Idn hon, Idn nhlt Id tgi hogch ngdn han. Kjch ban RCP8.5
cum ddo LUdi Liem vd Tri Tdn.
dupe dp dyng cho cdng trlnh
Ket luan va khuyen nghj mang tfnh vTnh ciiu, quy hoach,
ke hogch ddi ban.
sit dpng
Kjch bdn BDKH&NBD ludn
Vide xay dung va thpc hidn
cac gidi phap Lfng phd vdi BDKH tdn tgi nhOng dilm ehUa chic

ehan vl cdn phy thude vao vide
xdc djnh cae kjch bdn phat thdi
khi nha kfnh, nhijfng hieu bie't cdn

hgn che v l hd thdng khf hau toan
d u vd khu vpc, qua trinh tan
bang, phUdng phap xdy dpng
kjch bdn... Do dd, khi sCf dpng
kjch bdn trong danh gid tac ddng
eua BDKH, can xem xet mpi khd
ndng xdy ra eua khi hdu tUdng lai.
Hdi nghj toan eau ve BDKH ndm
2015 da de nghj IPCC vdo ndm
2018 cdng bd bdo cdo ddc biet ve
kjch ban ndng dp khf nhd kfnh va
ede tdc ddng khi nhiet dp toan
eau tdng 1,5°C so vdi thdi ky tiln
edng nghiep. Trdn ed sfl dd, Vidt
Nam eung se ed cdc cdp nhat
tUdng dng.
Tai li^u tham khdo
1) Bd TN&MT, 2009: Kich
ban BDKH, nudc biin dang cho
Viet Nam.
2) Bd TN&MT, 2012: Kich
ban BDKH. node bien ding cho
Viit Nam.
3) BdTN&MT,2015:/BDKH, nudc bien dang cho Viit
Nam (DU thdo).«

Tdi nguyen vd Mdi h-u'dng | Kyi-Tiling 1/2016

^^