Do we really need pesticides? - Fernan Pérez-Gálvez
-
0:07 - 0:13In 1845, Ireland's vast potato fields
were struck by an invasive fungal disease -
0:13 - 0:17that rapidly infested this staple crop.
-
0:17 - 0:19The effect was devastating.
-
0:19 - 0:22One million people died of famine,
-
0:22 - 0:26and over a million more were forced
to leave Ireland. -
0:26 - 0:32Nowadays, we avoid such agricultural
catastrophes with the help of pesticides. -
0:32 - 0:36Those are a range of manmade chemicals
that control insects, -
0:36 - 0:37unwanted weeds,
-
0:37 - 0:38funguses,
-
0:38 - 0:39rodents,
-
0:39 - 0:40and bacteria
-
0:40 - 0:42that may threaten our food supply.
-
0:42 - 0:45They've become an essential part
of our food system. -
0:45 - 0:49As populations have grown,
monoculture, single crop farming, -
0:49 - 0:52has helped us feed people efficiently.
-
0:52 - 0:57But it's also left our food
vulnerable to extensive attack by pests. -
0:57 - 1:01In turn, we've become more dependent
on pesticides. -
1:01 - 1:06Today, we annually shower over 5 billion
pounds of pesticides across the Earth -
1:06 - 1:09to control these unwanted visitors.
-
1:09 - 1:12The battle against pests,
especially insects, -
1:12 - 1:15has marked agriculture's long history.
-
1:15 - 1:17Records from thousands of years ago
-
1:17 - 1:21suggest that humans actively burned
some of their crops after harvest -
1:21 - 1:24to rid them of pests.
-
1:24 - 1:29There's even evidence from ancient times
that we recruited other insects to help. -
1:29 - 1:35In 300 A.D., Chinese farmers specially
bred ferocious predatory ants -
1:35 - 1:39in orange orchards
to protect the trees from other bugs. -
1:39 - 1:41Later, as large-scale farming spread,
-
1:41 - 1:47we began sprinkling arsenic, lead,
and copper treatments on crops. -
1:47 - 1:51But these were incredibly toxic
to humans as well. -
1:51 - 1:54As our demand for more,
safer produce increased, -
1:54 - 1:57so did the need for effective chemicals
-
1:57 - 2:00that could control pests
on a grander scale. -
2:00 - 2:05This ushered in the era
of chemical pesticides. -
2:05 - 2:09In 1948, a Swiss chemist named
Paul Hermann Müller -
2:09 - 2:12was awarded a Nobel Prize
for his discovery -
2:12 - 2:18of dichlorodiphenyltrichloroethane,
also known as DDT. -
2:18 - 2:23This new molecule had unparalleled power
to control many insect species -
2:23 - 2:28until the 1950s,
when insects became resistant to it. -
2:28 - 2:34Worse, the chemical actually drove
dramatic declines in bird populations, -
2:34 - 2:35poisoned water sources,
-
2:35 - 2:41and was eventually found to cause
long-term health problems in humans. -
2:41 - 2:45By 1972, DDT had been banned
in the United States, -
2:45 - 2:49and yet traces still linger
in the environment today. -
2:49 - 2:52Since then, chemists have been searching
for alternatives. -
2:52 - 2:56With each new wave of inventions,
they've encountered the same obstacle - -
2:56 - 2:59rapid species evolution.
-
2:59 - 3:01As pesticides destroy pest populations,
-
3:01 - 3:06they leave behind
only the most resistant individuals. -
3:06 - 3:09They then pass on their
pesticide-resisting genes -
3:09 - 3:11to the next generation.
-
3:11 - 3:13That's lead to the rise of super bugs,
-
3:13 - 3:16such as the Colorado potato beetle,
-
3:16 - 3:19which is resistant to over
50 different insecticides. -
3:19 - 3:24Another downside is that other bugs
get caught in the crossfire. -
3:24 - 3:29Some of these are helpful predators
of plant pests or vital pollinators, -
3:29 - 3:34so erasing them from agriculture
wipes out their benefits, too. -
3:34 - 3:36Pesticides have improved over time
-
3:36 - 3:39and are currently regulated by strict
safety standards, -
3:39 - 3:43but they still have the potential
to pollute soil and water, -
3:43 - 3:44impact wildlife,
-
3:44 - 3:46and even harm us.
-
3:46 - 3:51So considering all these risks,
why do we continue using pesticides? -
3:51 - 3:52Although they're imperfect,
-
3:52 - 3:57they currently may be our best bet
against major agricultural disasters, -
3:57 - 4:00not to mention mosquito-born diseases.
-
4:00 - 4:05Today, scientists are on a quest for
alternative pest control strategies -
4:05 - 4:07that balance the demands
of food production -
4:07 - 4:09with environmental concerns.
-
4:09 - 4:13Nature has become a major source
of inspiration, -
4:13 - 4:17from natural plant and fungal chemicals
that can repel or attract insects, -
4:17 - 4:21to recruiting other insects
as crop bodyguards. -
4:21 - 4:25We're also turning to high-tech solutions,
like drones. -
4:25 - 4:27Programmed to fly over crops,
-
4:27 - 4:30these machines can use
their sensors and GPS -
4:30 - 4:32to carry out more targeted sprays
-
4:32 - 4:36that limit a pesticide's wider
environmental impact. -
4:36 - 4:39With a combination
of biological understanding, -
4:39 - 4:40environmental awareness,
-
4:40 - 4:42and improved technologies,
-
4:42 - 4:47we have a better chance of finding
a holistic solution to pests. -
4:47 - 4:51Chemical pesticides may never shake
their controversial reputation, -
4:51 - 4:52but with their help,
-
4:52 - 4:55we can ensure that
agricultural catastrophes -
4:55 - 4:57stay firmly in our past.
- Title:
- Do we really need pesticides? - Fernan Pérez-Gálvez
- Description:
-
View full lesson: http://ed.ted.com/lessons/do-we-really-need-pesticides-fernan-perez-galvez
Annually, we shower over 5 billion pounds of pesticides across the Earth to control insects, unwanted weeds, funguses, rodents, and bacteria that may threaten our food supply. But is it worth it, knowing what we do about the associated environmental and public health risks? Fernan Pérez-Gálvez weighs the pros and cons of pesticides.
Lesson by Fernan Pérez-Gálvez, animation by Mighty Oak.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 05:18
Jessica Ruby approved English subtitles for Do we really need pesticides? - Fernan Pérez-Gálvez | ||
Jessica Ruby accepted English subtitles for Do we really need pesticides? - Fernan Pérez-Gálvez | ||
Jessica Ruby edited English subtitles for Do we really need pesticides? - Fernan Pérez-Gálvez | ||
Jennifer Cody edited English subtitles for Do we really need pesticides? - Fernan Pérez-Gálvez |