Why does climate change worry us? | Matilde Rusticucci | TEDxRíodelaPlata-TEDxChange |
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0:09 - 0:12The subject I wanted to talk to you about
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0:12 - 0:15is why we are worried
about climate change. -
0:16 - 0:19Climate change
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0:19 - 0:25is a thing that happens and has happened
since the beginning of the Earth. -
0:25 - 0:28That is what we call the climate system.
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0:28 - 0:30But, why a climate system?
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0:30 - 0:35The sun, which is the source
of energy of this whole system, -
0:35 - 0:40is the one that gives us energy,
radiates energy to our system. -
0:41 - 0:46Our system is composed
by the Earth, the ocean, the ices, -
0:46 - 0:49the atmosphere, the vegetation...
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0:49 - 0:52All these subsystems or little pieces
of this climate system -
0:52 - 0:54interact with each other.
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0:55 - 0:57Then we receive this radiation.
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0:57 - 1:00The Earth also emits radiation
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1:00 - 1:04that is trapped by the famous
greenhouse gases. -
1:04 - 1:06These gases,
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1:06 - 1:09part of those that make up the atmosphere,
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1:09 - 1:13are responsible for making
our living possible today, -
1:13 - 1:15and for giving us a nice temperature.
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1:15 - 1:18Greenhouse gases
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1:18 - 1:23are natural gases that exist
in the atmosphere. -
1:23 - 1:26But it's here where we have
to start realizing -
1:26 - 1:29that all of these subsystems
interact with each other. -
1:29 - 1:33What I mean is that if you change
any of these components, -
1:33 - 1:38this will affect the other
components in some way. -
1:38 - 1:42So, if you change the amount of radiation
that gets into the system, -
1:42 - 1:45or the amount of radiation
that gets out of it, -
1:45 - 1:48or the amount of ice
that could reflect radiation, -
1:48 - 1:51any of these changes
no matter how little they may seem, -
1:51 - 1:54will affect
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1:54 - 1:58the climate in our planet.
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1:58 - 2:01So, we know our climate has changed.
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2:01 - 2:04It can change for two main reasons:
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2:04 - 2:06natural reasons,
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2:06 - 2:11for climate has naturally changed
over millions of years. -
2:11 - 2:16We've been through ice ages
and interglacial periods, glacial ones... -
2:16 - 2:19We all remember all of this is measured
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2:19 - 2:23in hundreds or tens of thousands of years.
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2:24 - 2:28But climate can also change artificially
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2:28 - 2:31or inducted by the particular
action of man. -
2:31 - 2:35And it's there where we start worrying,
this is what we worry about. -
2:35 - 2:40Man is interacting with climate
in a way that is changing it -
2:40 - 2:42Why are we so sure about this?
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2:45 - 2:48We are so sure because of this graphic,
that seems a little too complex. -
2:48 - 2:50This is what we have to show.
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2:50 - 2:52We scientists,
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2:52 - 2:54from our international organizations,
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2:54 - 2:57this subject is discussed world-wide.
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2:57 - 3:00We can show, with that black curve,
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3:00 - 3:02what's the temperature observed
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3:02 - 3:06since the beginning
of the 18th century up to date. -
3:06 - 3:09This is the mean temperature
observed globally. -
3:09 - 3:13Well, we are able to know
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3:13 - 3:15how this temperature has changed
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3:15 - 3:17due to natural changes.
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3:17 - 3:19I mean,
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3:19 - 3:22changes in the amount of radiation
that enters the system, -
3:22 - 3:25due to changes in the Sun,
such as sunspots -
3:25 - 3:28and other changes the Sun suffers
in the amount of radiation it emits. -
3:28 - 3:32These changes would produce
the temperature following the blue curve. -
3:32 - 3:35As you see it is quite
below the black curve. -
3:35 - 3:39In order to reproduce
real temperature values, -
3:39 - 3:45we have to include man-made
changes in the analysis. -
3:45 - 3:48We are able to know that these two curves
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3:48 - 3:52are separated because of man-made actions.
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3:52 - 3:55If we were just having natural changes
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3:55 - 3:58temperature should be
much lower than today's. -
3:58 - 4:02And we can see differences
of, for instance, -
4:02 - 4:05more than half degree or one degree
Celsius, that seems little, -
4:05 - 4:08because this is a mean temperature
of the whole planet. -
4:08 - 4:11Global mean temperature:
summer, winter, poles, equator. -
4:11 - 4:15All of these, merged,
give us this mean temperature, -
4:15 - 4:17that may seem not so worrying.
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4:18 - 4:20But, what are we really worried about?
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4:21 - 4:25We see these changes,
we see how temperature, -
4:25 - 4:28in the upper chart, has risen
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4:28 - 4:30since 1850 until present.
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4:30 - 4:33We see it has a little
increase every year. -
4:33 - 4:35But it is increasing.
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4:35 - 4:38We see this accompanied not just
by temperature changes, -
4:38 - 4:41but also by increases in the sea level.
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4:42 - 4:44Why does the sea level rise?
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4:45 - 4:50The main cause for sea level
increases is this: -
4:50 - 4:53as the temperature
of the atmosphere rises, -
4:53 - 4:55the temperature of the water also rises.
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4:55 - 4:57The temperature of the ocean rises.
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4:57 - 5:01And when temperature rises,
there's an increase in volume. -
5:01 - 5:04As sea volume increases,
its level does so too. -
5:04 - 5:06So this is the main cause.
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5:06 - 5:08Of course, ice melting also contributes,
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5:08 - 5:10but that's not the main cause.
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5:10 - 5:14But we see how it has systematically
risen through the years. -
5:14 - 5:16And we see how, in the chart below,
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5:16 - 5:23the snow coat decreases, for example,
in the northern hemisphere. -
5:24 - 5:30That means we know there have been
changes in the whole climate system, -
5:30 - 5:35that are more easily illustrated,
for instance, by this case. -
5:35 - 5:38This is a glacier in Bolivia,
the Chacaltaya, -
5:38 - 5:42that has been photographed
in four occasions. -
5:42 - 5:47We see the glacier in 1940,
in the first picture up on the left. -
5:48 - 5:50Next one is from 1982.
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5:50 - 5:54Next is from 1996,
and the last one is from 2005. -
5:55 - 5:58We can see how the area covered
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5:58 - 6:01by this glacier has decreased.
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6:01 - 6:05This is a direct effect
of the temperature increase in this area. -
6:05 - 6:08This is Bolivia,
and that is a tropical glacier. -
6:08 - 6:11This is how we can show the impact it has.
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6:11 - 6:15We clearly see that the increase
of temperature locally, -
6:15 - 6:20although it seemed it had risen
just a little through the last centuries -
6:21 - 6:24-- only a degree Celsius
in almost more than one century -- -
6:24 - 6:27the impact of these changes,
on a local scale, -
6:27 - 6:29is much stronger.
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6:29 - 6:31For example, in the case of glaciers,
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6:31 - 6:33if one glacier disappears,
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6:33 - 6:36there is a serious impact
on the surrounding population. -
6:36 - 6:40Generally, the people
that live around glaciers -
6:40 - 6:43drink their meltwaters.
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6:44 - 6:45Meltwaters from glaciers.
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6:45 - 6:48The water they usually use,
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6:48 - 6:51such as for drinking,
feeding, or cultivate, -
6:51 - 6:52comes from these glaciers.
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6:52 - 6:57If the glacier does not freeze in winter,
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6:57 - 6:59there will be no water
for these people in summer. -
7:01 - 7:03Then, we are observing this.
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7:04 - 7:09But how do we feel day by day
that the temperature has risen? -
7:10 - 7:15We've seen recent pictures
of the heat wave in Moscow. -
7:15 - 7:19The heat wave that hit Moscow in July,
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7:19 - 7:23and all the surrounding area in Russia,
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7:23 - 7:26had a big impact on the population.
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7:26 - 7:29The amount of deaths due
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7:29 - 7:36to fire pollution
and high temperatures doubled. -
7:36 - 7:39This had also happened
not so many years before. -
7:39 - 7:41In 2003,
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7:41 - 7:44there was another heat wave in Europe,
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7:44 - 7:48very significant, where 15 thousand
people died in Paris -
7:48 - 7:51only because of the high temperatures.
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7:51 - 7:55Europe is, therefore, having
more and more heat waves. -
7:55 - 7:57But what does this mean?
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7:57 - 8:00We're not necessarily having
the temperatures that Male suffered. -
8:00 - 8:05It doesn't mean Moscow had temperatures
above 40 or 50 degrees Celsius. -
8:05 - 8:07It's measured in another way.
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8:07 - 8:09What we see is that
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8:09 - 8:13temperature goes above certain level,
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8:13 - 8:15an amount of times per month.
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8:16 - 8:19For example: in Moscow in July,
a maximum temperature of 25 ºC -
8:19 - 8:24is exceeded normally nine days per month.
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8:24 - 8:28What happened that July?
It was exceeded 31 days. -
8:28 - 8:32Every single day in that July
exceeded that threshold. -
8:32 - 8:35So, day by day, what we feel
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8:35 - 8:41is that we have more and more days
with high temperatures -
8:41 - 8:44and less days with temperatures
below the threshold, -
8:44 - 8:47with cold and fresh temperatures.
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8:47 - 8:49This is an example from Moscow,
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8:49 - 8:53but our research team here
works on data from Argentina. -
8:53 - 8:55What has happened in Argentina?
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8:55 - 8:58What do we know that has happened here?
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8:58 - 9:01In our country and
in the South America region, -
9:01 - 9:08we've had, systematically,
less and less temperatures -
9:08 - 9:09under a threshold.
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9:09 - 9:14I mean, we have less
and less low temperatures. -
9:14 - 9:18Especially in summer, we have
a smaller amount of fresh nights. -
9:18 - 9:20That typical fresh summer night,
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9:20 - 9:23well, that happens much less often.
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9:23 - 9:27And every time we have more cases
of warm temperatures -
9:27 - 9:30in months that used to be milder
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9:30 - 9:32such as fall or spring.
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9:32 - 9:36So, hotter days have spread over the year
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9:36 - 9:41to October, to March,
even to April and May. -
9:41 - 9:45So, we clearly feel that everyday.
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9:45 - 9:48Not necessarily very high temperatures,
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9:48 - 9:52but especially temperatures
above the threshold. -
9:52 - 9:55But we've recently had
another extreme event -
9:55 - 9:58in the city of Buenos Aires
and its surroundings, -
9:58 - 10:00that were the southeast blows.
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10:00 - 10:02What is a southeast blow?
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10:02 - 10:06It's a wind coming from the southeast,
or east, that is very persistent -
10:06 - 10:09and does not allow the river
to flow into the Atlantic Ocean. -
10:09 - 10:13And we don't necessarily have
more and more southeast blows. -
10:13 - 10:16What happens is that this southeast blow,
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10:16 - 10:18added to a higher river level,
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10:18 - 10:20produces a bigger impact.
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10:20 - 10:23So, a change in climate will not
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10:23 - 10:28necessarily produce an equal impact.
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10:28 - 10:31The main consequences of the reports
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10:31 - 10:34that we submit
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10:34 - 10:37is that the poorest countries
are the ones to suffer more. -
10:37 - 10:40The countries with less
resources, less prepared, -
10:40 - 10:43faced to the same extreme climatic event
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10:43 - 10:46will have more losses.
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10:46 - 10:48They've had more losses
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10:48 - 10:51and more serious consequences.
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10:51 - 10:54This has nothing to do
with climate change, -
10:54 - 10:57but the Haiti earthquake
compared to the Chile earthquake -
10:57 - 10:58showed significant differences.
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11:00 - 11:02What do we know about future climate?
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11:02 - 11:04This chart, that seems
a little complicated, -
11:04 - 11:06perhaps you've already seen it.
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11:06 - 11:07We know what is going to happen
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11:07 - 11:10with a very level of certainty.
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11:10 - 11:12So we know that temperature,
that's been rising, -
11:12 - 11:17that first black curve you see
on the left, lower part of the graph, -
11:17 - 11:18that's what has happened.
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11:18 - 11:20What is going to happen?
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11:20 - 11:22It will depend on how society reacts,
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11:22 - 11:24what measures it takes.
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11:24 - 11:26To see which one of those curves,
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11:26 - 11:29if the red, the green,
the blue or the fuchsia one, -
11:29 - 11:31is going to be our future.
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11:31 - 11:34We know there will be
an increase in temperature. -
11:34 - 11:36And we know this increase will be higher
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11:36 - 11:38in the northern hemisphere.
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11:38 - 11:41Because the northern hemisphere
is a continental hemisphere. -
11:41 - 11:43The southern hemisphere
has a larger sea surface, -
11:43 - 11:44it reacts more slowly.
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11:44 - 11:48But, again, impacts could be different.
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11:48 - 11:50They're not necessarily related
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11:50 - 11:53to how big the increase
of temperature will be. -
11:54 - 11:55So, we know...
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11:57 - 12:00There are reports that show
all these types of results. -
12:00 - 12:05And all of these results emerge
from the reports of the IPCC, -
12:05 - 12:07that stands for
-
12:07 - 12:11Intergovernmental Panel on Climate Change.
-
12:11 - 12:14This is a United Nations panel,
created over 20 years ago, -
12:14 - 12:17which has obtained the Nobel Peace Prize
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12:17 - 12:18along with Al Gore
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12:19 - 12:23a couple of years ago,
for its accomplishments. -
12:23 - 12:24It's a panel formed by experts.
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12:25 - 12:29I am a part of this panel,
I was part of the former report -
12:29 - 12:32and I will be part of the one
we are initiating this year. -
12:32 - 12:37And these results, given its accuracy,
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12:37 - 12:40are elaborated through many years.
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12:40 - 12:43Just for you to know, the last report
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12:43 - 12:45came to light in 2007.
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12:45 - 12:47There was a huge worldwide impact,
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12:47 - 12:50and a lot of interest
in what results we were publishing. -
12:50 - 12:53That report was begun in 2004.
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12:53 - 12:56The next one is going
to be released in 2013. -
12:56 - 12:59And we have to have a first
draft for next march, -
12:59 - 13:03because it is largely revised by experts.
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13:03 - 13:08Every result is contrasted
with different published works. -
13:08 - 13:11So, what's the doubt?
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13:11 - 13:15Why are there sometimes
doubts about climate change? -
13:15 - 13:18There are doubts
because developed countries, -
13:18 - 13:21those which elaborate future policies,
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13:21 - 13:24take into account these reports.
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13:26 - 13:29From the results of the IPCC reports,
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13:29 - 13:34policies are made for the future,
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13:34 - 13:37these are the big things we have to do.
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13:37 - 13:39What can we do about it?
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13:39 - 13:41Well, there are two main areas:
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13:41 - 13:43adapt to the change,
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13:43 - 13:47and/or try to relieve it.
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13:47 - 13:48What does this mean?
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13:48 - 13:51Adapting to the change:
we know the change is happening. -
13:51 - 13:53We know the change will happen.
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13:53 - 13:56The better we know,
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13:56 - 13:59the more we know, and more precisely
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13:59 - 14:01how much the temperature will increase,
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14:01 - 14:03how will rains in the Pampas rise,
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14:03 - 14:06or how much it will stop
raining in Mendoza, -
14:06 - 14:08or in northern Patagonia.
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14:08 - 14:10The more we know about it,
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14:10 - 14:13the better we will be able
to adapt to these changes. -
14:13 - 14:15Actually,
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14:15 - 14:20man himself adapts
to those gradual changes. -
14:20 - 14:22But basically, what we have to do
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14:22 - 14:25is work to relieve the change.
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14:25 - 14:28To try to stop emitting,
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14:28 - 14:32to stop rising the concentrations
of these greenhouse gases. -
14:32 - 14:38I mean, we mainly need to stop
emitting carbon dioxide, -
14:38 - 14:42that comes from the use of oil.
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14:42 - 14:47From our homes, to save energy.
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14:47 - 14:50Try not to waste electric power
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14:50 - 14:53by refrigerating large buildings
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14:53 - 14:56that are architecturally very well built,
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14:56 - 14:58but are not eco-friendly,
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14:58 - 15:01because they need, for instance,
a lot of refrigeration. -
15:01 - 15:04It's well known that buildings
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15:04 - 15:08is where the cost-benefit of change
makes a big impact. -
15:08 - 15:12So, we know a lot of this stuff.
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15:12 - 15:15They're published in the reports.
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15:15 - 15:18Then, what is that worries us
so much about climate change? -
15:18 - 15:20Mainly, what worries us the most
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15:20 - 15:22is that no measures are being taken.
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15:22 - 15:26That no policies are being made
for these changes, -
15:26 - 15:29to adapt to the change,
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15:29 - 15:31so that the impacts do not
result so negatively. -
15:31 - 15:37And even to, in some way,
take advantage of some of these changes -
15:37 - 15:39for our country and our region.
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15:40 - 15:42Thank you very much.
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15:42 - 15:43(Applause)
- Title:
- Why does climate change worry us? | Matilde Rusticucci | TEDxRíodelaPlata-TEDxChange |
- Description:
-
Matilde Rusticucci is an expert on climate change and professor at University of Buenos Aires. She belonged to the Climate Change Experts Panel of the United Nations and shares some insights on the changes we may expect if we do not do anything to change the present.
- Video Language:
- Spanish
- Team:
- closed TED
- Project:
- TEDxTalks
- Duration:
- 15:54