(gentle music)
- [Announcer] NASA's 2023 is officially in the books
and what a year it was!
From the successful return of samples
from 4.5 billion-year-old asteroid to the announcement
of the crew of the next manned mission to fly around the moon,
it's safe to say that NASA stayed busy.
And that goes double for the Landsat program,
as NASA's decades-long partnership
with the USGS crosses off its 51st year in orbit,
continuing to map and monitor our ever-changing planet
in remarkable detail.
So let's take a peek not just into the past
and some of the innovative ways researchers were able
to put Landsat data to work in 2023,
but also at how the Landsat program is preparing
for its next chapter.
(gentle music)
Even though it might evoke the image
of a grizzled prospector panning for gold
in 1850's California,
river or alluvial mining, as it's known,
is still used to this day
as a method of extracting precious minerals.
In fact, a research paper published in 2023 shows
a concerning trend in river mining worldwide.
Researchers use data from Landsats 5 and 7
to track river mining at almost 400 sites
across the world over a 37-year period.
Their results showed that over the past two decades,
river mining activity has been on the rise,
particularly in tropical areas.
And with that rise has come a whole slew
of negative environmental impacts,
such as increases in sediment deposits,
and deforestation, as well as decreases
in water quality and availability.
With the help of foundational data collected
by Landsat over the last 50 years,
researchers hope they can bring to light with the scale
and impact of river mining, emphasizing the need for action
to mitigate its environmental consequences.
Follow any given river all the way to and from its source,
and it's quite possible you'll find yourself
on the shore of a lake.
Lakes account for 3% of Earth's global land area,
storing vast reservoirs of freshwater essential
to our planet's ecosystems.
Water levels in these lakes fluctuate from year to year
due to factors both natural and manmade, from droughts
and floods to agricultural and domestic consumption.
So when researchers wanted
to track water levels over the past three decades
in lakes worldwide, they turned to Landsat.
A 2023 research paper analyzed almost 250,000 Landsat images
to track water levels in thousands of lakes
and reservoirs across the world between 1992 and 2020.
By combining imagery with climate
and hydrological models,
researchers were able to determine that 53%
of these water bodies had experienced a significant decline
in water levels over the past 30 years.
The cause of this decline?
Researchers say one factor is climate change.
As warmer and drier weather around many
of these lakes is driving higher rates
of evapotranspiration.
These findings stress the importance
of more effective water resource management
as nearly a quarter of the world's population live near
and depend on lakes that are experiencing water loss.
While the water levels in our world's lakes may be shrinking
when it comes to our oceans,
it's a different story altogether.
As global temperatures continue to creep higher,
so too do our sea levels,
which puts added pressure on vital coastal ecosystems.
Mangroves, tidal marshes, coral reefs,
and reef islands all play key roles in protecting
coastlines, providing natural habitats for animal
and plant life, and capturing and storing excess carbon.
These ecosystems are known to be resilient, having adapted
to gradual changes in historic sea levels.
But researchers wanted to find out
what effect rising global temperatures could possibly have
on our world's coastal habitats in the coming decades.
The research team used machine learning techniques trained
on millions of Landsat scenes to assess
how coastal ecosystems might react
to a potential rise in global temperature
from 1.5° to 3°C.
Their results painted a dire picture,
a 1.5° to 2°C temperature rise could see a sea level rise
of up to 4mm a year between 2080 and 2100,
which would double the amount of mapped tidal marsh.
Putting those numbers in perspective, by the year 2044,
our oceans could rise between three to four centimeters.
A 3 °C rise in temperature,
however, would expose almost all
of the world's mangroves and coral reefs.
And a large portion of tidal marshes to sea level rises
of at least seven millimeters per year,
which would hit 14 centimeters by 2044.
The researchers believe their study underscores
the urgent need for effective global climate policies
that aim at keeping temperature rise under 2 °C.
Any failure to do so could lead
to a significant loss in biodiversity
and put our vulnerable coastal communities
even further at risk.
These 2023 case studies clearly demonstrate
how important Landsat's ability to look into the past can be
for preparing for our future.
The Landsat program's, free
and open archive puts five decades worth
of Earth observations at researchers fingertips.
A decades-long legacy of observing, managing,
and adapting to change on earth.
In early 2023, the Landsat program announced plans
for continuing this legacy, Landsat Next.
Representing a quantum leap forward in Earth observation,
Landsat Next will be a triplet-configuration,
a constellation of three satellites orbiting in tandem,
taking a complete picture of the world every six days.
With the improved six-day revisit comes
an increased spatial resolution, allowing Landsat satellites
to capture smaller details
at a finer temporal resolution than before.
And Landsat Next will be going "superspectral"
hosting 26 spectral bands, unlocking new applications
for monitoring water quality, crop production, snow
and ice dynamics, and more.
2023 was without a doubt, an exciting year
for the Landsat program with data being put to use in ways
that continue to prove why the Landsat program is
a cornerstone of Earth observation.
So as we bid Landsat's 2023 a fond farewell,
we can turn our gaze forward to the exciting discoveries
that lay on the horizon for Landsat in 2024 and beyond...
(gentle music)