TED@NAS
Kelsey Johnson: The problem of light pollution -- and 5 ridiculously easy ways to fix it
Filmed:
Readability: 4.1
1,257,393 views
Ever gaze up at the starry night sky? This stunning view is at risk of disappearing -- unless we act now, says astrophysicist Kelsey Johnson. In this fascinating, unexpectedly funny talk, she explains how light pollution affects almost every species on earth (including us) and shares five "stupidly simple" things you can do to help solve the problem.
Kelsey Johnson - Astrophysicist, writer, educator
Kelsey Johnson has spent her life in awe of the universe, and she works to inspire that awe in future generations. Full bio
Kelsey Johnson has spent her life in awe of the universe, and she works to inspire that awe in future generations. Full bio
Double-click the English transcript below to play the video.
00:13
Unless you've spent quality time
on the International Space Station,
on the International Space Station,
0
1208
4143
00:17
this is probably not a view
you are super familiar with.
you are super familiar with.
1
5375
3434
00:20
This is the east coast
of the United States.
of the United States.
2
8833
3018
00:23
That's New York down there
in the lower right,
in the lower right,
3
11875
2226
00:26
and it's a band of light
all the way up through Washington DC.
all the way up through Washington DC.
4
14125
4184
00:30
Those cities are shining like jewels,
5
18333
2351
00:32
highways are traced by webs of light.
6
20708
3601
00:36
And all of that light is super photogenic.
7
24333
3226
00:39
But there's a problem.
8
27583
1459
00:41
That light is meant to be
illuminating our sidewalks,
illuminating our sidewalks,
9
29875
3976
00:45
and our streets and our houses.
10
33875
2101
00:48
Instead, it's actually
going up into the sky
going up into the sky
11
36000
2643
00:50
and out into the universe,
12
38667
1601
00:52
where it's not doing any of us any good.
13
40292
2083
00:55
When I see photos of this, of the Earth,
14
43625
3476
00:59
I see environmental catastrophe.
15
47125
2125
01:02
Those aren't jewels,
16
50625
1893
01:04
those are tumors.
17
52542
1291
01:07
I'm an astronomer,
18
55958
1268
01:09
so it's really no surprise
probably to anyone
probably to anyone
19
57250
2601
01:11
that I've always loved the night sky.
20
59875
2351
01:14
I'm kind of a walking cliché.
21
62250
1917
01:18
But when I was growing up in Minnesota,
22
66792
2517
01:21
one of my favorite things to do
on a summer evening
on a summer evening
23
69333
3101
01:24
was grab my old Raggedy Ann sleeping bag
24
72458
2643
01:27
and take it out into a field
behind my house,
behind my house,
25
75125
2309
01:29
where I would spend hours
looking at the night sky.
looking at the night sky.
26
77458
3476
01:32
And to do this, I had to brave
not only the darkness,
not only the darkness,
27
80958
3143
01:36
but also swarms of mosquitoes,
28
84125
2434
01:38
and my sleeping bag
really didn't smell very good.
really didn't smell very good.
29
86583
3268
01:41
(Laughter)
30
89875
1708
01:44
But there was one particular star
31
92708
2643
01:47
that I would look for, night after night.
32
95375
2143
01:49
And then I would play this game
33
97542
1726
01:51
where I would try to focus
on that star so intensely,
on that star so intensely,
34
99292
4267
01:55
that everything else
would fade from my view
would fade from my view
35
103583
2351
01:57
and that single star
would be all that I could see.
would be all that I could see.
36
105958
2935
02:00
I could only ever hold on to that focus
37
108917
2101
02:03
for a few fleeting moments.
38
111042
2517
02:05
But when I did,
39
113583
1351
02:06
I felt this deep sense
of connection to the universe.
of connection to the universe.
40
114958
3851
02:10
And almost a sense of vertigo,
41
118833
3351
02:14
like I was going to fall into space.
42
122208
2917
02:18
And when this happened --
43
126292
1851
02:20
I know this sounds kind of ridiculous,
44
128167
1851
02:22
but I would simultaneously feel
unfathomably insignificant
unfathomably insignificant
45
130042
5934
02:28
and also kind of weirdly important.
46
136000
2625
02:31
That star I looked to
night after night was called Vega.
night after night was called Vega.
47
139458
4226
02:35
Vega is the brightest star
in the constellation Lyra,
in the constellation Lyra,
48
143708
3726
02:39
which is not coincidentally
the name of one of my dogs.
the name of one of my dogs.
49
147458
2768
02:42
(Laughter)
50
150250
2476
02:44
But this experience is being lost.
51
152750
2809
02:47
My favorite constellation, Lyra,
52
155583
2268
02:49
this is what it would look like
from Manhattan.
from Manhattan.
53
157875
2191
02:52
For people who live in urban
and suburban environments,
and suburban environments,
54
160090
2594
02:54
if they go outside at night and look up,
55
162708
2643
02:57
instead of being awestruck
by the majesty of the universe,
by the majesty of the universe,
56
165375
4726
03:02
they see pretty much nothing.
57
170125
2042
03:05
These unremarkable,
completely blank night skies,
completely blank night skies,
58
173500
4643
03:10
of course are due to all of the light
we produce at night.
we produce at night.
59
178167
3809
03:14
Those very same lights
we see all the way from space
we see all the way from space
60
182000
2559
03:16
are shining up into the atmosphere,
61
184583
1976
03:18
where they bounce around
and create this featureless smog of light.
and create this featureless smog of light.
62
186583
5185
03:23
And that featureless
smog of light has a name.
smog of light has a name.
63
191792
2434
03:26
It's called light pollution.
64
194250
2226
03:28
As an astronomer,
65
196500
1268
03:29
I can actually tell
how bad light pollution is
how bad light pollution is
66
197792
2684
03:32
by the brightness of stars
I can see in the sky.
I can see in the sky.
67
200500
2559
03:35
And it turns out
68
203083
1268
03:36
that when you're trying to unlock
the secrets of the cosmos,
the secrets of the cosmos,
69
204375
3226
03:39
it's really helpful
to be able to see the cosmos.
to be able to see the cosmos.
70
207625
3809
03:43
And --
71
211458
1250
03:44
[Laughs]
72
212833
1000
03:45
Truth.
73
213958
1250
03:48
And this light that we're trying to detect
74
216625
2018
03:50
is coming from millions or billions
of light-years away,
of light-years away,
75
218667
4142
03:54
and so it's generally pretty faint.
76
222833
3226
03:58
And as an astronomer,
77
226083
1768
03:59
I fight with this every day to do my job,
78
227875
2476
04:02
and I have to tell you,
it is a really big problem.
it is a really big problem.
79
230375
3625
04:08
But the problem is far worse
80
236917
3059
04:12
than just losing some
whimsical ability to gaze at the stars.
whimsical ability to gaze at the stars.
81
240000
5226
04:17
For example,
82
245250
1268
04:18
countless plant and animal
species are affected.
species are affected.
83
246542
2934
04:21
So we could talk about sea turtles
84
249500
3143
04:24
or pollinators
85
252667
2434
04:27
or any of these super important species
86
255125
2976
04:30
that are also cute.
87
258125
2309
04:32
Instead, I want to talk
88
260458
1268
04:33
about these quietly unassuming dog whelks.
89
261750
3434
04:37
You may have seen them around
90
265208
1393
04:38
and not given them
really a whole lot of thought.
really a whole lot of thought.
91
266625
2726
04:41
But they're pretty cool.
92
269375
1268
04:42
So in an entire year
93
270667
1934
04:44
a dog whelk will rarely move
more than about 10 meters.
more than about 10 meters.
94
272625
4268
04:48
That means that when
they are attacking their prey
they are attacking their prey
95
276917
3892
04:52
they can hit this brisk pace
of about a millimeter an hour.
of about a millimeter an hour.
96
280833
2959
04:56
And --
97
284708
1268
04:58
(Laughter)
98
286000
2000
05:01
This works out OK,
99
289333
1435
05:02
because they attack things like barnacles.
100
290792
2601
05:05
(Laughter)
101
293417
3708
05:10
So these dog whelks live
in the intertidal area of coasts,
in the intertidal area of coasts,
102
298750
4184
05:14
where, it turns out,
103
302958
1268
05:16
they're a pretty key part
of the ecosystem.
of the ecosystem.
104
304250
2059
05:18
Not only are they one of the most
dominant invertebrate predators,
dominant invertebrate predators,
105
306333
4810
05:23
but other animals, like crabs and birds,
think they're pretty tasty.
think they're pretty tasty.
106
311167
5059
05:28
So that leaves these poor snails
in a kind of precarious situation,
in a kind of precarious situation,
107
316250
3393
05:31
because if they go too low in the water,
108
319667
2392
05:34
then crabs are a threat,
109
322083
1810
05:35
but if they come out of the water too far,
110
323917
2101
05:38
birds are going to have a feast.
111
326042
1625
05:41
Why is an astronomer
telling you about dog whelks?
telling you about dog whelks?
112
329083
2542
05:45
I ask that myself.
113
333083
1250
05:47
Because their behavior
is impacted by light pollution.
is impacted by light pollution.
114
335833
3143
05:51
For example,
115
339000
1268
05:52
if dog whelks are subjected
to artificial light at night
to artificial light at night
116
340292
3226
05:55
they're about twice as likely
to stay under the water with a predator.
to stay under the water with a predator.
117
343542
4226
05:59
And that puts them at increased risk.
118
347792
1892
06:01
And it's not like they can make
a speedy escape.
a speedy escape.
119
349708
2268
06:04
And so these --
120
352000
1268
06:05
(Laughter)
121
353292
1250
06:07
And the other issue
is because they literally move
is because they literally move
122
355292
2434
06:09
at a snail's pace.
123
357750
1809
06:11
If a population is wiped out,
124
359583
2685
06:14
it can take decades to replenish.
125
362292
2934
06:17
And that, in turn, affects
the rest of their ecosystem
the rest of their ecosystem
126
365250
2559
06:19
and the other species, like the birds
and the barnacles and the crabs.
and the barnacles and the crabs.
127
367833
4018
06:23
So this is just one
small and slimy example
small and slimy example
128
371875
3226
06:27
of how light pollution
can unleash a cascade effect
can unleash a cascade effect
129
375125
3393
06:30
on an entire ecosystem.
130
378542
2351
06:32
Virtually every species
that has been studied to date
that has been studied to date
131
380917
4434
06:37
is impacted by light pollution.
132
385375
1809
06:39
And that includes humans.
133
387208
1351
06:40
So let's talk about us.
134
388583
2018
06:42
You are probably not surprised to hear
135
390625
2393
06:45
that light pollution can affect
your ability to sleep well at night.
your ability to sleep well at night.
136
393042
3892
06:48
But you might be surprised to hear
that light pollution is linked to obesity.
that light pollution is linked to obesity.
137
396958
3959
06:54
In fact, in a recent study
138
402167
1351
06:55
they found that light pollution
contributed to over 70 percent
contributed to over 70 percent
139
403542
3351
06:58
of the obesity rates in 80 countries.
140
406917
2625
07:02
More than that,
141
410375
1309
07:03
light pollution actually contributed
about the same amount to excess weight
about the same amount to excess weight
142
411708
4143
07:07
as eating junk food.
143
415875
1333
07:10
And it gets worse.
144
418458
1560
07:12
For people who are subjected
145
420042
1976
07:14
to significant amounts
of artificial light at night
of artificial light at night
146
422042
2934
07:17
they're about 50 percent more likely
to get breast cancer.
to get breast cancer.
147
425000
4101
07:21
And in fact, light pollution
is correlated with types of cancer
is correlated with types of cancer
148
429125
3226
07:24
across the board.
149
432375
1351
07:25
And in controlled lab experiments
150
433750
1643
07:27
there's a direct link between
increased artificial light at night
increased artificial light at night
151
435417
4476
07:31
and a rate of tumor growth.
152
439917
1791
07:34
You might be wondering how normal light
153
442792
2851
07:37
could possibly impact cancer rates.
154
445667
3267
07:40
It likely all comes down
to the super important hormone
to the super important hormone
155
448958
2810
07:43
called melatonin,
156
451792
1767
07:45
which we have evolved
over millions of years
over millions of years
157
453583
2268
07:47
to produce on a day-night cycle,
or a circadian rhythm.
or a circadian rhythm.
158
455875
3893
07:51
What happens is that when light impacts
159
459792
2517
07:54
the retina at the back of our eye at night
160
462333
2185
07:56
it can disrupt melatonin production,
161
464542
2517
07:59
and when melatonin
production is disrupted,
production is disrupted,
162
467083
2268
08:01
a whole chain of other
chemical processes are affected,
chemical processes are affected,
163
469375
2851
08:04
and that includes estrogen production.
164
472250
2143
08:06
And when we throw
this chemical balance out of whack,
this chemical balance out of whack,
165
474417
2726
08:09
really bad things can happen.
166
477167
1851
08:11
In fact, things are so bad,
167
479042
1642
08:12
that the International Agency
for Cancer Research
for Cancer Research
168
480708
2810
08:15
has said that disrupting
the human circadian rhythm
the human circadian rhythm
169
483542
3309
08:18
is a probable carcinogen.
170
486875
1875
08:22
Also, for fun, I want to let you know
171
490292
1809
08:24
that light pollution has been linked to,
172
492125
1934
08:26
let's see -- headaches, anxiety,
depression, diabetes,
depression, diabetes,
173
494083
3060
08:29
cardiovascular disease
and the list goes on.
and the list goes on.
174
497167
2267
08:31
But maybe you don't care
about your health.
about your health.
175
499458
2310
08:33
We're all going to die anyway,
176
501792
1434
08:35
you might as well die
in a brightly lit room.
in a brightly lit room.
177
503250
2268
08:37
(Laughter)
178
505542
2642
08:40
The fact that you're laughing
about death is kind of amazing.
about death is kind of amazing.
179
508208
2935
08:43
(Laughter)
180
511167
1166
08:45
You might still care about money.
181
513208
1917
08:48
The money that's spent
on that wasted light,
on that wasted light,
182
516083
2185
08:50
and I mean just the light
that's going out into the universe,
that's going out into the universe,
183
518292
2934
08:53
and not doing us any good,
184
521250
1268
08:54
is three billion dollars a year.
185
522542
1851
08:56
That's enough money to build, like,
186
524417
2017
08:58
1,000 utility-grade windmills,
187
526458
2560
09:01
or fund the entire DC public-school
system for over two years,
system for over two years,
188
529042
4267
09:05
or -- this is my favorite,
because I really want one
because I really want one
189
533333
2476
09:07
but I can't afford one --
190
535833
1643
09:09
buy 30,000 Tesla Model X SUVs.
191
537500
2851
09:12
(Laughter)
192
540375
2018
09:14
And that includes
the electric car tax credit.
the electric car tax credit.
193
542417
2250
09:18
And then there are the existential costs.
194
546708
3268
09:22
I don't have any data
195
550000
2268
09:24
on how losing touch
with our place in the cosmos
with our place in the cosmos
196
552292
3601
09:27
impacts us.
197
555917
1851
09:29
But I believe
198
557792
2559
09:32
that this probably impacts our humanity
199
560375
2059
09:34
more than any of the other
scary statistics I can share with you.
scary statistics I can share with you.
200
562458
3518
09:38
And it's getting worse with time.
201
566000
1601
09:39
The amount of light pollution
is doubling roughly every 35 years.
is doubling roughly every 35 years.
202
567625
5601
09:45
That means that within the next decade
203
573250
3268
09:48
virtually the entire eastern half
of the United States
of the United States
204
576542
3559
09:52
will be perpetually brighter
than twilight.
than twilight.
205
580125
2958
09:56
And there's another issue
with light pollution.
with light pollution.
206
584250
2768
09:59
The problem is way worse
than we can see with our own eyes.
than we can see with our own eyes.
207
587042
3101
10:02
Our eyes have evolved
to just detect this tiny range
to just detect this tiny range
208
590167
2809
10:05
of the full spectrum of light.
209
593000
2101
10:07
All of this other light that we can't see,
210
595125
2351
10:09
this invisible light,
211
597500
2059
10:11
also has a pollution problem.
212
599583
1643
10:13
Mostly it's from modern technology,
213
601250
1726
10:15
things like cell phones
or car-to-car radar,
or car-to-car radar,
214
603000
2351
10:17
or now apparently we need appliances
that can talk to each other.
that can talk to each other.
215
605375
3208
10:21
All of this modern technology
is putting out strong signals
is putting out strong signals
216
609792
3017
10:24
that can completely swamp
217
612833
2143
10:27
this exceedingly faint light
we're trying to detect
we're trying to detect
218
615000
3768
10:30
from the rest of the universe
outside Earth,
outside Earth,
219
618792
2142
10:32
which just for the record,
is most of the universe.
is most of the universe.
220
620958
2834
10:36
(Laughter)
221
624708
3459
10:42
And then, there are satellites.
222
630083
2268
10:44
Satellites are a problem at both
visible and invisible wavelengths.
visible and invisible wavelengths.
223
632375
4143
10:48
A host of private companies have plans
to deploy tens of thousands of satellites
to deploy tens of thousands of satellites
224
636542
4184
10:52
into Earth orbit,
225
640750
1768
10:54
where they will not only outnumber,
226
642542
2059
10:56
literally outnumber
the visible stars in the sky,
the visible stars in the sky,
227
644625
3393
11:00
while also beaming
invisible light back to Earth.
invisible light back to Earth.
228
648042
4351
11:04
So for astronomers like me,
229
652417
1934
11:06
who use invisible light
to study the universe,
to study the universe,
230
654375
2476
11:08
it's going to be like staring at the Sun
231
656875
3059
11:11
and trying to see
a birthday candle behind it.
a birthday candle behind it.
232
659958
2417
11:15
Alright, I want to be clear
233
663750
2184
11:17
that there's nothing inherently wrong
with any of this modern technology.
with any of this modern technology.
234
665958
4143
11:22
With cell phones
or satellites or car radar.
or satellites or car radar.
235
670125
3268
11:25
I'm not sure about kitchen appliances.
236
673417
2184
11:27
(Laughter)
237
675625
1351
11:29
I haven't broken down
238
677000
1268
11:30
and gotten an oven
that talks to my cell phone yet.
that talks to my cell phone yet.
239
678292
2642
11:32
And I use lights at night
like everybody else.
like everybody else.
240
680958
2750
11:37
But here's the thing.
241
685583
1726
11:39
Some problems in the world,
242
687333
1976
11:41
like we've heard about today
and you'll hear more about,
and you'll hear more about,
243
689333
2643
11:44
are overwhelming
and they seem intractable.
and they seem intractable.
244
692000
3809
11:47
Visible light pollution
is not one of these problems.
is not one of these problems.
245
695833
3726
11:51
This is actually stupidly simple, OK?
246
699583
3310
11:54
So here are five
super simple things you can do.
super simple things you can do.
247
702917
3726
11:58
Don't use lights
brighter than you need to.
brighter than you need to.
248
706667
2892
12:01
Don't use lights when you don't need them.
249
709583
2435
12:04
Those lights you're using,
250
712042
1267
12:05
make sure they're shielded down,
251
713333
1601
12:06
so they're not shining up into the sky.
252
714958
2143
12:09
And let's talk about LED lights.
253
717125
2101
12:11
If you have a choice,
don't buy the blue ones.
don't buy the blue ones.
254
719250
4309
12:15
Look for words like "warm white."
255
723583
2726
12:18
If you buy LEDs with words like
"natural light" or "daylight,"
"natural light" or "daylight,"
256
726333
4143
12:22
that's like saying you hate space.
257
730500
2018
12:24
(Laughter)
258
732542
6267
12:30
And finally,
259
738833
2518
12:33
you could advocate for this.
260
741375
1934
12:35
Even in your local community,
261
743333
1435
12:36
find out if there's a lighting code
262
744792
1684
12:38
and whether it could be made
more night-sky friendly.
more night-sky friendly.
263
746500
2851
12:41
Or dare I say, you could even advocate
at the federal level,
at the federal level,
264
749375
3559
12:44
by politely asking our federal officials,
265
752958
2518
12:47
some of whom may be here,
266
755500
1268
12:48
to please not auction off
our view of the invisible universe
our view of the invisible universe
267
756792
4226
12:53
to the highest bidder to pollute at will,
268
761042
1976
12:55
which is actually what happens.
269
763042
2434
12:57
Now, like a good professor,
270
765500
2768
13:00
I have homework for you.
271
768292
1625
13:02
If you have never seen
a truly dark night sky,
a truly dark night sky,
272
770917
4351
13:07
I want you to go out
and experience one for yourself.
and experience one for yourself.
273
775292
3976
13:11
Because if you don't,
274
779292
1976
13:13
you don't know what you're missing,
275
781292
3017
13:16
and you don't know
what humanity is losing.
what humanity is losing.
276
784333
3476
13:19
Thank you.
277
787833
1268
13:21
(Applause)
278
789125
3000
ABOUT THE SPEAKER
Kelsey Johnson - Astrophysicist, writer, educatorKelsey Johnson has spent her life in awe of the universe, and she works to inspire that awe in future generations.
Why you should listen
Kelsey Johnson teaches students both inside and outside of the classroom, using astronomy as a "gateway" science to nurture curiosity and support science literacy. Raised by a single mom, Johnson spent countless nights outside under the stars, where she developed a love for "big picture" questions about the nature of reality and the universe. Influenced by her own experience, she founded the Dark Skies, Bright Kids program in 2009 to enhance science education in under-served areas.
Johnson's curiosity about the cosmos -- and everything in it -- has been the primary driver of her career, leading her to devote her life to learning, exploration and teaching. Her research has tackled questions ranging from "How were the most ancient objects in the universe formed?" to "What can the smallest galaxies tell us about the evolution of the universe?" She has also broken new ground teaching, developing nontraditional courses such as "Unsolved Mysteries in the Universe" and "Math and Beauty in the Cosmos." Johnson is a professor at the University of Virginia and the president of the Astronomical Society of the Pacific.
In 2016, Johnson was appointed by the White House Office of Science and Technology Policy to the Astronomy and Astrophysics Advisory Committee, and in 2017 she was elected to the board of the American Astronomical Society. Her research has received awards including the NSF CAREER Award, a Packard Fellowship and an NSF Distinguished lectureship, as well as being a Kavli Frontiers of Science Fellow. Johnson has also won several teaching awards, and she was recently named as one of four “ACC Distinguished Professors” in the Atlantic Coast Conference of universities. She received an inaugural "Public Service" award from UVA for her work promoting science literacy
Johnson's writing has appeared in Scientific American, Washington Post, the New York Times, Ms. Magazine and The Chronical of Higher Education. She earned her BA in physics from Carleton College, and her MS and PhD in astrophysics from the University of Colorado. She lives in rural Virginia with her family, including three cats and two very large dogs.
Kelsey Johnson | Speaker | TED.com