Original subtitles

(waves crash)

- [Narrator] Sea level rise is one

of the most serious consequences

of the human-induced climate crisis.

The water rise is from heat expansion

of the oceans, melting polar caps, vanishing glaciers

and the loss of fresh water.

Satellites are an essential tool to monitor the changes

and help climate modelers prepare us for the future.

(exciting music)

(thoughtful music)

NOAA's GOES-T satellite

in geosynchronous orbit is a recent edition

of the next generation of satellite.

It is the western hemisphere's most sophisticated

weather observing and environmental monitoring system

covering over half the globe.

Along with the decades long Sentinel series of satellites.

Sentinel-6, a collaboration of European

and US space agencies and climate monitoring institutes

is continuing the mission

of uninterrupted sophisticated data gathering

for climate scientists and modelers.

- Well, the main instruments on board

include a dual frequency radar altimeter

and this is the primary instrument of the mission

and that's the one that's measuring sea surface height,

significant wave height and wind speed over the ocean.

And from those measurements we can actually have

the superb measurements that we expect of sea level rise,

but also the waves, the significant wave height

which is the top one third of the waves if you were to look

at them in time, so the biggest waves that you would see.

This is important for marine operations

and the altimeters provide perhaps some

of them the best datasets that we have today

over the global ocean.

We have plenty of boys in the ocean that measure waves

but they're often in the coastal zone.

And it's only when you go to the altimetry

that you can really have is this global coverage.

- We all know sea level is rising.

And how do we know that?

Because we measured this since the nineties

from space through a series of satellite.

It started with TOPEX/Poseidon

which was a French American satellite, followed

by the Jason-1, two and three series

which was also French American satellite.

And Sentinel-6, as you said also called Jason-CS, stands

for continuity of service is meant to go in orbit

to follow Jason-3 to continue the record of the sea level

since about 30 years.

And we want to continue that record for another five years

and demonstrate and quantify the sea level rise

we have been observing since the nineties

in average about 3.2 millimeters per year.

Even though the scientist tells us

in the last year this has been accelerating

in particular due to the acceleration in melting of ice.

So over the last years it's

about four millimeters every year we record

in the sea level.

- We talk about the impact of melting snow and ice surfaces

in terms of what's known as the albedo effect.

When snow is dry, it's very reflective

and of course that helps to reflect sunlight back out

into space and the consequence is we can reduce the amount

of melting this way.

However, as ice and snow melt, the albedo

and the reflectivity becomes lower and this has the effect

of absorbing more of the solar energy.

This contributes to further warming and further melting.

And so it's a runaway progressive effect caused

by the reduction in the albedo.

(water splashes)

- Satellites are a major source

of global timely long-term data sets

which is in particular very important for climate

because we need to have long-term data series

to actually understand how the climate is changing

over decades, for example

and to also understand what the trend

of these changes are going to be.

And so we are using a large variety of different data sets.

We're mainly concentrating

on the European Space Agencies data sets.

And there's a mixture between data sets that come

from a Heritage Mission, like for instance ENVISAT

and ERS because we are looking also back of course

in terms of climate.

But we're also using data that are coming in right now

for example, from the Sentinel's missions that are running

under the Copernicus program that we are running together

or collaborating with the European Union

and EUMETSAT together.

But we're also using actually quite new technology

and satellites that address scientific questions

that haven't been addressed before.

So it's a mixture of different data sources

that we are trying to combine in these climate data records.

- What we do is we also work

with partner agencies worldwide.

So we exchange data over climate, we do work

on calibration activities, we support activities linked

to, for example ice loss volume monitoring.

And we have done that with the US partners

over IMBIE campaign over the Arctic region.

(moving music)

- [Narrator] To calibrate the satellites

in orbit, scientists on the ground take measurements

in-situ all around the globe from the Antarctic

to the Arctic and glaciers around the world.

They then compare results and validate the satellite data.

- And we are producing climate data records.

So long-term data records of climate relevant indicators,

let's say, one of them you see behind me.

We are also producing climate data records

for glaciers in particular the extent

of the glacier, the velocity, but also the elevation.

- The ice loss in the Alps is comparably strong.

So we have similar strong mass loss I think

in the Andes of Peru and Bolivia

but also in Patagonia they have similar rates.

But the most difficult thing

or problematic thing is

that this ice loss in the Alps is still increasing.

So now I think for something like 30, 35 years we see higher

and higher loss.

And this takes place despite the fact that the region

where ice can melt,

the so-called ablation region is shrinking.

And this is a very strong signal

for accelerated climate change and an increased forcing

which means that temperatures have to increase

and increase and push the snow line higher

and higher so that more areas are exposed to melt.

- Those projections tell us what glaciers will look like.

What they will look like very much depends

on what we human beings will we do next

in terms of greenhouse gas emissions.

So if we manage to mitigate climate change very much,

we'll have glaciers that will still shrink

but will shrink a lot less than

if we don't manage to get hold

of this climate crisis that is literally unfolding.

So in the worst case where really

or emissions will continue to grow unabated

until the end of the century, well, this place

where we're standing is gonna be ice free for sure

but even the highest elevation that we see here,

they are most likely be ice free as well.

On the contrary, if we now really manage to put effort

in abating emissions we'll be able to save say,

at least 40% of the ice.

So half of this place is gone anyway

but still there will be something that we can look at

and that we can show to our children

and that our childrens can show to our grandchildren.

(waves crash)

- I think the recent record since CryoSat, one

of our satellites has been flying has shown

that there's quite some fluctuation

in the amount of ice transferred from land to the ocean.

However, we have seen

that sea level rise has been accelerating

over the last several years.

One of the reasons is thought to be related

to the increased melting of land glaciers

and a recent publication has shown

that in fact the contribution

of glaciers to sea level rise is increasing.

And we've gone from a situation in the 1970s

and eighties where it was contributing only a fraction

of a millimeter a year

to something closer to one millimeter a year.

This is around 20, 25%

of the sea level rise signal globally.

And so glaciers are obviously having

an increasing contribution to sea level rise

over the last two decades.

- The European Space Agency is doing a lot

in providing the evidence for a changing climate.

If you think about the Earth Observation Program

for example, I think the majority

of activities are really directly addressing this question.

And it starts at the perceiving new satellite measurements.

So, one of the core activities of the European Space Agency

in the Earth Observation Program is

of course to build satellites and there's different flavors

of these satellites that address new technologies,

new scientific questions like

for instance the earth explorers.

But then there is the Sentinel missions

that we are developing in collaboration

with the European Union and with EUMETSAT who provide,

for example continuity on many of these measurements

but also improve over coming decades because we have a lot

of experience in these measurements.

And I think, so we're doing in ISSA I think something

it's almost like covering the entire food chain

of providing climate relevant information.

And I think this is quite an amazing fact

because we really follow through

from the beginning of the measurement up

to the point where we're actually talking

to the people who put the policies in place.

And I think that's a really good foundation

that we're providing from the ISSA's perspective.

- So when you fly around the earth

at 400 kilometers you have a very unique point

of view that is at the same time a privilege and a curse.

It is a privilege because

of course not many people get to do it.

Not many people get to fly in space

and look down at the earth.

It is a curse because what you see is

at the same time so beautiful

and so fragile that it certainly breaks your heart.

And it is what inspired me to start talking about

what is happening on planet Earth

and about everything that we take for granted today.

And as a matter of fact, that same feeling

of helplessness and desire to do something I felt

in this past couple of days, talking to the scientists,

talking to the explorers and being myself part of the group

on this glacier and looking with my eyes, touching

with my hands, the same things that I felt from space.

So if I had to summarize the feelings

which is always hard because feelings don't come

in a linear way, they're always very mixed up.

I feel a little bit of urgency

and because it's me,

I also feel hope that people will listen

and understand the urgency of what is happening

and how fast we have to react

before everything that we have will disappear.

(waves crash)

- Low lying regions of the world

of course are going to suffer the most from this kind

of impact in terms of ice melt and sea level rise.

Of course, countries like Bangladesh already suffering

from the increased probability

of storm surges as sea level rises.

And coastal inundation is a problem

for millions of people in Bangladesh.

We also see it in more developed countries.

We have a situation in Venice during seasons

of the year where tidal range and storm surges combined

with sea level rise to cause what's known as acqua alta.

And there the whole of the city of Venice is inundated

by water on a regular basis during these periods of time.

So I think the societal impact of coastal inundation

and flooding can affect millions of people in the future

and so we need to monitor the effects

of melting ice and sea level rise.

- We got the long term data and we got the long term trend

and we now finally realize that you have the long term trend

but you also have superposed local variations.

So some years it stops and other years it goes very quick.

So it's a really very dynamic system

and that just really means

that we have to have a continuous monitoring from space.

- I believe that there is an awareness that is growing

but is not enough yet.

So water being probably one of the resources

that we really need to check

and we are here because of that.

Water has a cycle that we have interfered with.

Ice turns into water, turns into atmospheric water

and it accelerates hurricanes, it accelerate flooding,

it's all connected and we have interfered with that cycle.

So now we have to do something to take a step back.

But one of the things

that we can do is preservation without pollution.

So little steps that everybody can do, have a bottle

of water and reuse it instead

of continuing buying extra new bottles of water

and polluting the Earth with the plastic

and using extra water that we don't need.

We can live on very little water.

We are just don't used to do it because we don't think it

and we don't think about it and we take it for granted.

I believe that the perspective that I have comes

from the awareness that on the space session we live

on very limited resources.

We have to recycle them and we have

to respect that awareness.

- What we're doing in the climate office

and not just in the climate office but

in the European Space Agency Earth Observation Program

at large is I think you know 90, 99%

supporting the cause of understanding A,

of what our climate is doing,

how our climate is changing and that

in turn can actually inform policy makers to take action

of what needs to be done to either mitigate that effect,

so basically, for example, limit emissions,

or to adapt to things that we cannot change anymore.

It's a very important physical evidence

to give decision makers and policy makers a base

to come up with plans of how we address this issue.

(water gurgling)

- Ice is changing a lot and ice is melting a lot.

Whether it's a problem of course long term it's a problem

because the sea level ice will go up.

But it's also to some degree an opportunity

for some of the Arctic countries

that they can develop their countries.

So it's climate change, monitor what is happening,

make sure we can give a qualified statement,

and especially this space is very important

to give a qualified statement of what is really happening

and not just some model prediction

or some fancy outlook which could be way off.

So I think we are the guys who give the hardcore facts

and as you say, I've been here for many years.

I've seen the change on my own eyes because

before we even got involved with European Space Agency,

we did a lot of airborne, a lot of mapping work.

We met with the first satellites already

in the very late 1970s

as the very first users of satellite navigation, namely

for mapping remote and distant areas.

So it's been really amazing to see

and also amazing to see the changes and changes are big.

- [Interviewer] Yeah.

- No doubt about that.

- And we are reproducing these data sets also

for the benefit of addressing

these international climate drivers so

that we actually know where we're standing at the moment

in terms of the state of the climate and what actions need

to be taken in the future in terms of policy

and decision making and adaptation and mitigation actions

for example, in the future.

- Because of the availability

of information that we are constantly bombarded with

there is a general feeling that we can all be experts

and at everything and come up with our own opinion.

I don't want to dismiss anybody's opinion

but I do want to listen to what experts and people

who have devoted their lives

to a certain study have to say.

Now it's a cycle.

We have scientists who use their instruments

to gather data, study those data and come out with a theory.

And once they come out with a theory and everybody agrees

to it, then we should probably listen to that.

And how do they get those instruments?

How do they gather that data?

Well there is a whole community

of people, technicians, engineers, astronauts, operators

that work constantly, incessantly to create the instruments

and to position them and to create the basis so

that the data can be collected in the correct way.

- The sea level will go up, no doubt about that.

So people in Holland and the very low lying areas,

they should have good reasons to be concerned.

So do we in Denmark.

But again, right now it's only 10 centimeters.

So we are talking 2,100, we talk anywhere

between 30, 40 centimeter and a meter,

then it's a little bit more concerning.

And again, that's where this long term space mission,

they would tell these people who make the modeling

and the prediction in the future,

if they made the modeling earlier, will it really fit

what we see today?

If you take all the data today, will it fit in 10 years?

That's why you have the big value of these continuous data

and also the continuous measurements really

of do the satellites measure the right thing?

Is the radar really measuring the surface?

Or it's measuring somewhere else on the ice?

That's all the thick questions we are concerned with.

- [Narrator] Most scientists agree we are past the point

of no return.

Now the focus is on trying

to mitigate the most serious effects on the planet.

- So it is a concern of course

and eventually we should do something about it.

And again, the space mission can tell you

in the long run, if you change something in the CO2,

the political side, will it really matter?

And for instance, the CO2 also in the Copernicus Program

and the ESA missions, you have CO2 missions

which are really useful to actually pinpoint

who are the bad guys in this game,

who is not cutting back eventually.

- As a scientist, I think we can provide data

and the satellite data help us to do so.

The issue with the glaciers

and the shrinking glaciers is a global scale phenomenon

where people are really concerned that

in the future there is no more ice or much less ice.

And what we can provide as scientists is solid data

about how much ice there is, how the ice masses change

and maybe when you do some computer modeling also

how much ice there will be in the future.

And over the past 20, 30 years,

I think the reporting from us was more

and more, yes, they are shrinking

and they just are shrinking globally and they do it stronger

and stronger and we can repeat this information again

and again and have it in IPCC reports

and say, hey, there's a problem

but of course in the end it depends

if this message is picked up and converted to action.

And here is very soon the place where the engagement

of scientists end because this is a political thing.

And what we can do is provide the best data

and the best uncertainty information we can get

and say really we are sure about this

and about this and about this and not so sure about this

and then politicians have to decide on

if they want to do something about it

and we hope that at some point this will happen.

(atmospheric sounds)