Giong nhu hang tram cu dan khac
tren dao Moushuni thuoc bang Tay Bengal, cu Sheihk Alauddin, 60 tuoi, chua tung
nghe noi cum tu “trai dat am dan len”. Nhung cu dang hung chiu nhung
tac dong cua qua trinh nay. “Ban dem, chung toi chi biet cau troi va hy vong
nuoc bien khong cuon troi gia dinh minh”, nguoi dan ong song tren hon dao
thua dan von la mot phan cua vuon quoc gia Sunderbans - rung duoc lon nhat the
gioi - cho biet. Khi thuy trieu len, muc nuoc bien tran sat dinh con de cao hon
6 met so voi nha cu Alauddin canh do.
Sau 10 nam nghien cuu Vinh Bengal, cac nha hai duong hoc cho
biet muc nuoc bien o Sunderban dang dang len voi toc do 3,14 mm moi nam so voi
muc trung binh 2 mm cua the gioi, de doa xoa so cac vung dat trung cua An Do va
Bangladesh. Theo nha nghien cuu Sugato Hazra o Dai hoc Jadavpur (bang Tay
Bengal), it nhat 15 hon dao dang chiu anh huong cua trieu cuong trong khi tinh
trang bo bien bi xam thuc dang lan den nhieu dao khac.
Thang truoc, tieu ban theo doi bien doi khi hau LHQ dua ra
ket luan rang cac hoat dong cua con nguoi gay ra tinh trang am nong cua trai dat,
va du bao nhieu dot han han, nang nong va nuoc bien dang cao. Nhung voi vuon
quoc gia Sunderban – hinh thanh tu hang tram hon dao va la noi cu tru cua ho
Bengal cung nhu nhieu loai dong vat quy hiem cua An Do, hiem hoa bien doi khi
hau dang hien huu truoc mat. “Mua mang t
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Nha tren dao Sagar bi hu hong
do tinh trang nuoc bien dang cao va xam thuc bo bien.
(Anh: Gulf-times) |
hat bat do luong mua it oi nhung chung toi con biet di dau?”, Alauddin vua
noi vua huong mat ra thua dat kho nut cua gia dinh. Han han roi sau do mua nhieu
va do man cua dat gia tang khien vung dat nay khong con trong duoc cay luong
thuc va nhung nguoi song bang nghe nong gio phai ra khoi kiem song. Hien co it
nhat 4 trieu cu dan song tren quan dao rong 9.630 km2 ngap tran cay
duoc nay.
Cac chuyen gia hang dau ve khi hau cua LHQ du doan trong the
ky nay, nhiet do se tang them 1,8-4oC, va muc nuoc bien tang 17,78 -
58,42 cm, co nguy co nhan chim cac hon dao. Tac dong nay tham chi lon hon neu
bang o Nam Cuc va dao Greenland lon nhat the gioi tan chay.
400 ho gia dinh song tren dao Moushuni be nho van chua biet dieu gi dang xay den.
Cach do khong xa, hai hon dao da chim xuong day bien va 3 thap nien qua, dai
duong bao la da nuot chung khoang 100 km2 rung duoc o Sunderbans.
Thuc trang xoi mon dat do nuoc bien 5 nam qua cung da lan sau vao dao den 15 m
va pha huy rung duoc tren nhieu dao.
Hang the ky qua, rung duoc song nho vao su ket hop nuoc bien va nuoc ngot tu cac
con song nhung nay nhieu rung duoc dang hap hoi do nuoc bien dang cao khien
nguon nuoc nuoi duong rung duoc tro nen “man hoa”. Cay coi tren cac dao cung do
nga, khien tinh trang xoi mon dat tro nen tram trong hon. Kanti Ganguly, mot
quan chuc bang Tay Bengal cho biet chinh quyen quyet dinh boi bo, nang cao de
dieu va gia tang dien tich rung duoc tai Sunderbans de bao ve cac hon dao. Nhung
theo nha hai duong hoc Hazra, nhung bien phap nay co le da qua tre...
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Vi khuan duoi day bien
co the han che Trai dat am dan len
Nhung vi khuan song quanh nui lua bun Haakon Mosby duoi day bien Barents
o Bac cuc dang gop phan kiem che hien tuong am dan len cua Trai dat bang
cach “nhai” khi methane nong dang ro ri tu mieng nui lua. Nhom
nha khoa hoc o Duc va Phap phat hien vi khuan tieu thu methane moi co
dang archaea don bao hiem khi oxy mang ten ANME-3 song
ben canh 2 loai vi khuan khac o nui lua co do sau 1.250 m duoi bien. No
chi ton tai o noi co the lay duoc chat dinh duong tu bien va methane tu
nui lua. Vi khuan nay co the an 40% luong methane - thanh phan chinh cua
khi dot tu nhien dong thoi la khi gay hieu ung nha kinh - duoc thai ra
boi chung phat trien nhanh chi trong lop bun mong.
Phat hien nay khong chi co the giup lam sang to cach thuc hoat dong cua
vi khuan tieu thu methane ma con co the lan ra manh moi lam the nao bien
methane thanh nhung nhien lieu de su dung hon nhu methanol hoac butane.
Tai California (My), methane noi bot tu day bien gan Santa Barbara duoc
giu lai xu ly de cung cap nang luong cho gan 200 can nha. La khi thai
cua qua trinh dot chay nhien lieu hoa thach, methane gay hieu ung nha
kinh manh gap 21 lan so voi khi carbon dioxide (CO2).
T.A (Theo Reuters) |
Theo Reuters, Bao Can ThoArticle source http://w4rum.com/959.t
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