WEBVTT

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The subject I wanted to talk to you about

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is why we are worried
about climate change.

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Climate change

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is a thing that happens and has happened
since the beginning of the Earth.

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That is what we call the climate system.

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But, why a climate system?

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The sun, which is the source
of energy of this whole system,

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is the one that gives us energy,
radiates energy to our system.

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Our system is composed
by the Earth, the ocean, the ices,

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the atmosphere, the vegetation...

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All these subsystems or little pieces
of this climate system

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interact with each other.

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Then we receive this radiation.

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The Earth also emits radiation

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that is trapped by the famous
greenhouse gases.

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These gases,

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part of those that make up the atmosphere,

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are responsible for making
our living possible today,

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and for giving us a nice temperature.

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Greenhouse gases

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are natural gases that exist
in the atmosphere.

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But it's here where we have
to start realizing

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that all of these subsystems
interact with each other.

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What I mean is that if you change
any of these components,

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this will affect the other
components in some way.

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So, if you change the amount of radiation
that gets into the system,

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or the amount of radiation
that gets out of it,

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or the amount of ice
that could reflect radiation,

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any of these changes
no matter how little they may seem,

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will affect

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the climate in our planet.

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So, we know our climate has changed.

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It can change for two main reasons:

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natural reasons,

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for climate has naturally changed
over millions of years.

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We've been through ice ages
and interglacial periods, glacial ones...

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We all remember all of this is measured

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in hundreds or tens of thousands of years.

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But climate can also change artificially

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or inducted by the particular
action of man.

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And it's there where we start worrying,
this is what we worry about.

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Man is interacting with climate
in a way that is changing it

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Why are we so sure about this?

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We are so sure because of this graphic,
that seems a little too complex.

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This is what we have to show.

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We scientists,

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from our international organizations,

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this subject is discussed world-wide.

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We can show, with that black curve,

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what's the temperature observed

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since the beginning
of the 18th century up to date.

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This is the mean temperature
observed globally.

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Well, we are able to know

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how this temperature has changed

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due to natural changes.

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I mean,

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changes in the amount of radiation
that enters the system,

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due to changes in the Sun,
such as sunspots

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and other changes the Sun suffers
in the amount of radiation it emits.

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These changes would produce
the temperature following the blue curve.

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As you see it is quite
below the black curve.

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In order to reproduce
real temperature values,

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we have to include man-made
changes in the analysis.

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We are able to know that these two curves

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are separated because of man-made actions.

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If we were just having natural changes

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temperature should be
much lower than today's.

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And we can see differences
of, for instance,

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more than half degree or one degree
Celsius, that seems little,

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because this is a mean temperature
of the whole planet.

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Global mean temperature:
summer, winter, poles, equator.

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All of these, merged,
give us this mean temperature,

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that may seem not so worrying.

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But, what are we really worried about?

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We see these changes,
we see how temperature,

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in the upper chart, has risen

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since 1850 until present.

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We see it has a little
increase every year.

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But it is increasing.

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We see this accompanied not just
by temperature changes,

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but also by increases in the sea level.

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Why does the sea level rise?

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The main cause for sea level
increases is this:

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as the temperature
of the atmosphere rises,

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the temperature of the water also rises.

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The temperature of the ocean rises.

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And when temperature rises,
there's an increase in volume.

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As sea volume increases,
its level does so too.

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So this is the main cause.

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Of course, ice melting also contributes,

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but that's not the main cause.

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But we see how it has systematically
risen through the years.

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And we see how, in the chart below,

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the snow coat decreases, for example,
in the northern hemisphere.

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That means we know there have been
changes in the whole climate system,

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that are more easily illustrated,
for instance, by this case.

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This is a glacier in Bolivia,
the Chacaltaya,

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that has been photographed
in four occasions.

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We see the glacier in 1940,
in the first picture up on the left.

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Next one is from 1982.

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Next is from 1996,
and the last one is from 2005.

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We can see how the area covered

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by this glacier has decreased.

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This is a direct effect
of the temperature increase in this area.

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This is Bolivia,
and that is a tropical glacier.

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This is how we can show the impact it has.

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We clearly see that the increase
of temperature locally,

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although it seemed it had risen
just a little through the last centuries

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-- only a degree Celsius
in almost more than one century --

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the impact of these changes,
on a local scale,

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is much stronger.

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For example, in the case of glaciers,

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if one glacier disappears,

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there is a serious impact
on the surrounding population.

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Generally, the people
that live around glaciers

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drink their meltwaters.

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Meltwaters from glaciers.

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The water they usually use,

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such as for drinking,
feeding, or cultivate,

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comes from these glaciers.

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If the glacier does not freeze in winter,

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there will be no water
for these people in summer.

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Then, we are observing this.

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But how do we feel day by day
that the temperature has risen?

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We've seen recent pictures
of the heat wave in Moscow.

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The heat wave that hit Moscow in July,

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and all the surrounding area in Russia,

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had a big impact on the population.

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The amount of deaths due

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to fire pollution
and high temperatures doubled.

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This had also happened
not so many years before.

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In 2003,

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there was another heat wave in Europe,

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very significant, where 15 thousand
people died in Paris

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only because of the high temperatures.

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Europe is, therefore, having
more and more heat waves.

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But what does this mean?

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We're not necessarily having
the temperatures that Male suffered.

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It doesn't mean Moscow had temperatures
above 40 or 50 degrees Celsius.

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It's measured in another way.

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What we see is that

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temperature goes above certain level,

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an amount of times per month.

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For example: in Moscow in July,
a maximum temperature of 25 ºC

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is exceeded normally nine days per month.

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What happened that July?
It was exceeded 31 days.

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Every single day in that July
exceeded that threshold.

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So, day by day, what we feel

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is that we have more and more days
with high temperatures

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and less days with temperatures
below the threshold,

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with cold and fresh temperatures.

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This is an example from Moscow,

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but our research team here
works on data from Argentina.

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What has happened in Argentina?

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What do we know that has happened here?

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In our country and
in the South America region,

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we've had, systematically,
less and less temperatures

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under a threshold.

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I mean, we have less
and less low temperatures.

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Especially in summer, we have
a smaller amount of fresh nights.

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That typical fresh summer night,

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well, that happens much less often.

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And every time we have more cases
of warm temperatures

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in months that used to be milder

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such as fall or spring.

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So, hotter days have spread over the year

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to October, to March,
even to April and May.

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So, we clearly feel that everyday.

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Not necessarily very high temperatures,

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but especially temperatures
above the threshold.

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But we've recently had
another extreme event

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in the city of Buenos Aires
and its surroundings,

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that were the southeast blows.

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What is a southeast blow?

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It's a wind coming from the southeast,
or east, that is very persistent

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and does not allow the river
to flow into the Atlantic Ocean.

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And we don't necessarily have
more and more southeast blows.

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What happens is that this southeast blow,

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added to a higher river level,

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produces a bigger impact.

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So, a change in climate will not

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necessarily produce an equal impact.

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The main consequences of the reports

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that we submit

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is that the poorest countries
are the ones to suffer more.

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The countries with less
resources, less prepared,

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faced to the same extreme climatic event

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will have more losses.

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They've had more losses

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and more serious consequences.

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This has nothing to do
with climate change,

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but the Haiti earthquake
compared to the Chile earthquake

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showed significant differences.

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What do we know about future climate?

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This chart, that seems
a little complicated,

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perhaps you've already seen it.

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We know what is going to happen

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with a very level of certainty.

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So we know that temperature,
that's been rising,

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that first black curve you see
on the left, lower part of the graph,

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that's what has happened.

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What is going to happen?

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It will depend on how society reacts,

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what measures it takes.

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To see which one of those curves,

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if the red, the green,
the blue or the fuchsia one,

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is going to be our future.

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We know there will be
an increase in temperature.

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And we know this increase will be higher

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in the northern hemisphere.

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Because the northern hemisphere
is a continental hemisphere.

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The southern hemisphere
has a larger sea surface,

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it reacts more slowly.

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But, again, impacts could be different.

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They're not necessarily related

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to how big the increase
of temperature will be.

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So, we know...

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There are reports that show
all these types of results.

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And all of these results emerge
from the reports of the IPCC,

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that stands for

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Intergovernmental Panel on Climate Change.

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This is a United Nations panel,
created over 20 years ago,

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which has obtained the Nobel Peace Prize

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along with Al Gore

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a couple of years ago,
for its accomplishments.

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It's a panel formed by experts.

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I am a part of this panel,
I was part of the former report

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and I will be part of the one
we are initiating this year.

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And these results, given its accuracy,

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are elaborated through many years.

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Just for you to know, the last report

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came to light in 2007.

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There was a huge worldwide impact,

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and a lot of interest
in what results we were publishing.

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That report was begun in 2004.

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The next one is going
to be released in 2013.

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And we have to have a first
draft for next march,

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because it is largely revised by experts.

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Every result is contrasted
with different published works.

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So, what's the doubt?

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Why are there sometimes
doubts about climate change?

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There are doubts
because developed countries,

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those which elaborate future policies,

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take into account these reports.

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From the results of the IPCC reports,

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policies are made for the future,

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these are the big things we have to do.

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What can we do about it?

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Well, there are two main areas:

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adapt to the change,

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and/or try to relieve it.

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What does this mean?

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Adapting to the change:
we know the change is happening.

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We know the change will happen.

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The better we know,

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the more we know, and more precisely

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how much the temperature will increase,

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how will rains in the Pampas rise,

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or how much it will stop
raining in Mendoza,

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or in northern Patagonia.

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The more we know about it,

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the better we will be able
to adapt to these changes.

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Actually,

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man himself adapts
to those gradual changes.

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But basically, what we have to do

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is work to relieve the change.

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To try to stop emitting,

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to stop rising the concentrations
of these greenhouse gases.

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I mean, we mainly need to stop
emitting carbon dioxide,

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that comes from the use of oil.

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From our homes, to save energy.

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Try not to waste electric power

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by refrigerating large buildings

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that are architecturally very well built,

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but are not eco-friendly,

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because they need, for instance,
a lot of refrigeration.

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It's well known that buildings

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is where the cost-benefit of change
makes a big impact.

00:15:08.000 --> 00:15:11.976
So, we know a lot of this stuff.

00:15:12.000 --> 00:15:14.578
They're published in the reports.

00:15:14.602 --> 00:15:17.976
Then, what is that worries us
so much about climate change?

00:15:18.000 --> 00:15:19.951
Mainly, what worries us the most

00:15:19.975 --> 00:15:21.976
is that no measures are being taken.

00:15:22.000 --> 00:15:25.976
That no policies are being made
for these changes,

00:15:26.000 --> 00:15:28.625
to adapt to the change,

00:15:28.649 --> 00:15:31.286
so that the impacts do not
result so negatively.

00:15:31.310 --> 00:15:36.976
And even to, in some way,
take advantage of some of these changes

00:15:37.000 --> 00:15:38.976
for our country and our region.

00:15:39.991 --> 00:15:41.977
Thank you very much.

00:15:42.001 --> 00:15:43.001
(Applause)