Climate change poses a grave threat to the natural world as well as human well-being,
safety, and livelihoods. As of 2023, the global average temperature was 1.18°C higher than the
20th century average (NOAA, 2024). Symptoms of this warming include rising sea levels and
more extreme weather events (Lee et al., 2023). The impacts of climate change vary across
geographic regions, and low-income, low-emitting countries unfortunately bear disproportionate
effects and vulnerability (Lee et al., 2023).
For example, the Philippines emits only 0.48% of all global emissions (UNDP, 2024), yet
it is one of the countries most at risk to climate change (The World Bank Group, 2022). This
high risk can be attributed to the Philippines’ unique archipelagic geography, impoverished and
rapidly growing populations, and high-precipitation tropical environment (Holden & Marshall,
2018). Specifically, risk can manifest through severe storms like typhoons.
Typhoons are becoming stronger due to higher sea temperatures and rising sea levels, and global warming is simultaneously making their frequencies, paths, velocities, wind speeds, and storm surges more severe.
(Holden & Marshall, 2018; Sevieri & Galasso, 2021; Elsner et al., 2008)
Typhoons in the
Philippines lead to displacement of people, morbidity and mortality, property and crop damage,
and economic loss; local economic activity alone is reduced up to 3% in the case of intense
typhoons (Strobl, 2019).
One of the most powerful typhoons ever recorded made landfall in the Philippines on
November 8th, 2013. This storm, called Typhoon Haiyan, also known as Super Typhoon
Yolanda, was the largest and most severe storm to strike the Philippines to date (Singer, 2014).
Yolanda killed 6,300 people in the Philippines—more than triple the death toll of Hurricane
Katrina—and caused economic damages equivalent to 4.8% of the country’s GDP (NDRRMC,
Republic of the Philippines, 2013; Ravago et al., 2015; The World Bank, 2022). Two of this
project’s members, Hillary and Hans, barely survived Yolanda as children while living in
Tacloban, the city where Yolanda made landfall.
Remotely sensed imagery presents a unique opportunity to understand and respond to
climate change symptoms, including typhoons and other natural hazards. Especially during a
fast-moving event like Yolanda and in the wake of such an event where there is dangerous
damaged terrain and limited infrastructure and human or financial resources, it can be
exceptionally challenging for people to collect data on the ground. Remote sensing imagery,
however, is freely accessible from many government agencies, can be analyzed from anywhere,
and can give high temporal and spatial resolution results at near real-time.
NASA Black Marble
is one of many such free imagery tools. Black Marble, which has been available since 2012, is a
daily calibrated and highly corrected (e.g., for atmospheric, lunar, terrain, etc. effects/noise)
nighttime lights product suite derived from day/night band (DNB) radiances recorded on the
Visible Infrared Imaging Radiometer Suite (VIIRS) instrument on the Suomi National
Polar-orbiting Partnership (Suomi NPP) satellite (Román et al., 2018).
By recording exclusively
anthropogenic radiance (all other types are filtered out as noise in the correction process) at
night, Black Marble radiance or "brightness" can serve as a proxy for electricity consumption,
urbanization, and GDP (Román et al., 2018). This anthropogenic radiance is typically a product
of street lights, storefront lights or signs, overflow from indoor lighting, and vehicle lights. Thus,
Black Marble is incredibly helpful in measuring disaster impacts and recovery time given that
typhoons and other natural hazards typically cause economic losses and electricity outages, and
that recovery is marked by redevelopment of cities, livelihoods, and infrastructure systems.