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