1
00:00:02,910 --> 00:00:06,641
Methane, like carbon dioxide, is
an important greenhouse gas

2
00:00:06,703 --> 00:00:10,434
that's contributed to about 1/3
of global warming. In recent

3
00:00:10,496 --> 00:00:13,792
years, atmospheric methane
levels have reached record

4
00:00:13,854 --> 00:00:17,399
highs. While fossil fuels,
agriculture and landfills make

5
00:00:17,461 --> 00:00:21,130
up a large percentage of human
caused sources, about 1/3 of

6
00:00:21,192 --> 00:00:24,861
methane emissions actually comes
from wetlands. What you're

7
00:00:24,923 --> 00:00:28,281
seeing here is a visualized
dataset of wetland methane

8
00:00:28,344 --> 00:00:32,013
emissions from around the globe
throughout the last several

9
00:00:32,075 --> 00:00:35,308
decades. These highlighted
regions are of particular

10
00:00:35,371 --> 00:00:38,729
interest because of their
concentrated wetland methane

11
00:00:38,791 --> 00:00:42,460
sources, which scientists are
working to better understand.

12
00:00:42,522 --> 00:00:46,253
Wetlands act as both a source
and sink for greenhouse gases,

13
00:00:46,315 --> 00:00:50,171
which means they both release
and store them. Wetland habitats

14
00:00:50,233 --> 00:00:53,280
are filled with things like
waterlogged soils and

15
00:00:53,342 --> 00:00:57,198
permafrost, which is what makes
them sizable carbon sinks. But

16
00:00:57,260 --> 00:01:00,867
as a warming climate causes
wetland soils to warm or flood

17
00:01:00,929 --> 00:01:04,536
carbon is released into the
atmosphere as methane. Methane

18
00:01:04,598 --> 00:01:08,329
is produced when there's a lack
of oxygen available for tiny

19
00:01:08,392 --> 00:01:12,309
carbon digesting microbes that
live in the soil. So in wetlands

20
00:01:12,371 --> 00:01:16,227
were flooded soils are deprived
of oxygen, those microbes that

21
00:01:16,289 --> 00:01:20,020
would have otherwise produced
carbon dioxide instead produce

22
00:01:20,083 --> 00:01:23,316
methane. NASA uses remote
sensing to monitor methane

23
00:01:23,378 --> 00:01:27,358
emissions from wetlands through
instruments like EMIT aboard the

24
00:01:27,420 --> 00:01:31,027
International Space Station,
airplane mountain instruments

25
00:01:31,089 --> 00:01:34,945
like AVIRIS NG and satellites
like Landsat and Europe Sentinel

26
00:01:35,007 --> 00:01:38,863
5 P. Locating and measuring the
sources of atmospheric methane

27
00:01:38,925 --> 00:01:42,843
is key to understanding how to
limit them so we can make better

28
00:01:42,905 --> 00:01:44,460
decisions for our future.