1
00:00:04,490 --> 00:00:09,210
the polar ice caps have been shrinking
2
00:00:06,990 --> 00:00:11,910
in summer and expanding in winter for
3
00:00:09,210 --> 00:00:14,219
millions of years but in the last three
4
00:00:11,910 --> 00:00:15,900
decades the Arctic sea ice at the end of
5
00:00:14,219 --> 00:00:18,990
each summers melt has been getting
6
00:00:15,900 --> 00:00:22,109
steadily smaller the decline was already
7
00:00:18,990 --> 00:00:23,849
alarming but in 2007 when the sea ice
8
00:00:22,109 --> 00:00:26,430
melts shattered the previous record by
9
00:00:23,850 --> 00:00:27,960
almost twenty-five percent researchers
10
00:00:26,430 --> 00:00:30,990
at NASA's Goddard Space Flight Center
11
00:00:27,960 --> 00:00:34,380
wondered is this an anomaly or part of
12
00:00:30,990 --> 00:00:38,940
an even more alarming trend we have had
13
00:00:34,380 --> 00:00:42,540
low ice cover since 1998 in the Arctic
14
00:00:38,940 --> 00:00:45,539
and what that means is that you have
15
00:00:42,540 --> 00:00:48,809
more open water in the region and with
16
00:00:45,539 --> 00:00:52,710
more open water you're getting more
17
00:00:48,809 --> 00:00:55,468
solar energy into the system so the
18
00:00:52,710 --> 00:00:59,550
Arctic Ocean has actually been warming
19
00:00:55,469 --> 00:01:01,770
up as the ice melts less light energy is
20
00:00:59,550 --> 00:01:03,629
reflected back into space and more of
21
00:01:01,770 --> 00:01:07,200
the sun's energy is absorbed into the
22
00:01:03,629 --> 00:01:09,330
ocean which fuels further melting in
23
00:01:07,200 --> 00:01:11,510
march two thousand eight the ice cap
24
00:01:09,330 --> 00:01:14,460
rebounded to a near normal winter level
25
00:01:11,510 --> 00:01:16,920
but much of this ice was thin single
26
00:01:14,460 --> 00:01:18,899
year ice and after a record rate of
27
00:01:16,920 --> 00:01:21,119
melting in the month of August the ice
28
00:01:18,900 --> 00:01:24,479
shrank to its second smallest extent on
29
00:01:21,119 --> 00:01:26,850
record if it keeps on going then the
30
00:01:24,479 --> 00:01:30,929
potential is that you lose the perennial
31
00:01:26,850 --> 00:01:34,110
ice altogether then we'll have a blue
32
00:01:30,930 --> 00:01:37,430
ocean in the Arctic now if the ocean
33
00:01:34,110 --> 00:01:41,490
becomes low there will be a lot of
34
00:01:37,430 --> 00:01:45,479
environmental impacts there are a lot of
35
00:01:41,490 --> 00:01:47,369
ecological impacts chemie so says the 30
36
00:01:45,479 --> 00:01:49,590
years of satellite data we have on
37
00:01:47,369 --> 00:01:52,500
Arctic sea ice suggests that it's not
38
00:01:49,590 --> 00:01:54,899
likely to recover as a scientist he is
39
00:01:52,500 --> 00:01:58,229
intrigued by the trends but personally
40
00:01:54,899 --> 00:02:00,770
he worries about the planets future well
41
00:01:58,229 --> 00:02:05,869
it makes me feel sad
42
00:02:00,770 --> 00:02:10,788
a lot of things can happen in terms of
43
00:02:05,869 --> 00:02:13,970
the impacts to the environment impacts
44
00:02:10,788 --> 00:02:19,369
to the ecosystem not just in the Arctic
45
00:02:13,970 --> 00:02:21,500
but for the whole whole earth and the
46
00:02:19,370 --> 00:02:25,580
ocean is such a big part of the climate
47
00:02:21,500 --> 00:02:27,440
system and you / curve it a little bit
48
00:02:25,580 --> 00:02:31,160
and you're going to chance the climate
49
00:02:27,440 --> 00:02:33,109
of the world one result of such global
50
00:02:31,160 --> 00:02:34,810
climate change has already begun to
51
00:02:33,110 --> 00:02:37,400
emerge at the other end of the earth
52
00:02:34,810 --> 00:02:39,709
summer sea ice minima in the southern
53
00:02:37,400 --> 00:02:41,959
hemisphere have not been declining as
54
00:02:39,709 --> 00:02:44,239
warmer ocean water promotes evaporation
55
00:02:41,959 --> 00:02:47,810
which creates more snow to feed the
56
00:02:44,239 --> 00:02:50,150
Antarctic ice fields NASA scientists are
57
00:02:47,810 --> 00:02:52,310
using a suite of satellites to study sea
58
00:02:50,150 --> 00:02:54,049
ice at both poles trying to better
59
00:02:52,310 --> 00:02:55,959
understand how a complex set of
60
00:02:54,049 --> 00:02:58,900
phenomena such as cloud cover
61
00:02:55,959 --> 00:03:01,489
reflectivity a thickness of the ice
62
00:02:58,900 --> 00:03:04,400
weather patterns like La Nina and El
63
00:03:01,489 --> 00:03:07,180
Nino and ocean temperature affect the
64
00:03:04,400 --> 00:03:07,180
trends we see today
65
00:03:13,140 --> 00:03:15,200
you