On May 13, 2021, the British Antarctic Survey observed a massive chunk of ice breaking off Antarctica. A generation ago, journalists would have had very little specific information to write about such an event. But in this case, we almost knew immediately that the iceberg A-76 measured around 4,320 square kilometers (about 1,668 square miles) in size, making it the largest berg in the world at that point. European Space Agency’s Copernicus Sentinel-1 imagery showed that A-76 was 170 kilometers (105.6 miles) in length and 25 kilometers (15.5 miles) wide — slightly larger than the Spanish island of Majorca — and calved from the western side of the Ronne Ice Shelf, lying in the Weddell Sea, in Antarctica.
Because of the quick, continuous and unbiased coverage they provide, satellites have emerged as the primary source of information for scientists tracking developments in Antarctica. Beyond just remote places though, satellites today have become an integral part of monitoring the whole planet — be it the ice and forest covers, the rising sea levels, measuring Earth’s temperature or greenhouse gas emissions.
As is with scientists and climate experts, satellite data can now be widely used by journalists to report on environmental changes, climate patterns, weather or natural disaster events. Since these environment-monitoring missions are all driven at the levels of national governments and intergovernmental agencies like the United Nations, the data is mostly publicly available. One just needs to know where to look and how to report.
Let’s explore some of the ways satellites can help us report on climate change.
POLAR WARMING
The warming of poles has powerful implications for our planet. The melting polar ice not only contributes to sea level rise, but also leads to further global warming.
The World Meteorological Organization and the United Nations Framework Convention on Climate Change both note polar ice sheets as an “essential climate variable within the Global Climate Observing System. However, it recognizes that monitoring the vast, remote Arctic and Antarctic regions “is a challenge and only feasible from space.”
In addition to national space agencies (like NASA and ESA), other organizations that study the changes in the polar regions and publish data on regular updates include the U.S. National Ice Center, U.S. National Snow and Ice Data Center, U.S. National Centers for Environment Information, Arctic Monitoring and Assessment Programme, International Arctic Research Center and Canada Polar Knowledge.
The U.S. NSIDC portal, in particular, is an excellent source for data for covering the Arctic and Antarctic. It provides an update during the first week of each month, or more frequently as conditions warrant. For instance, according to its September bulletins, the Arctic Sea ice extent for that month was the 12th lowest in the 43-year satellite record.
A comprehensive list of various other organizations studying the Arctic can be found on the University of Washington’s Libraries page. The page lists many Arctic monitoring organizations, national government agencies and non-governmental organizations focusing on research in the Arctic region. These organizations produce reports, assessments, policy recommendations and original research, most of which are open source, and can be accessed directly from those organizations’ websites. Many of these also monitor the Antarctic.
FOREST COVER
Deforestation accounts for about 20% of global annual greenhouse gas emissions, according to various sources. Again, because of the vast area they can cover quickly, satellite images have emerged as a reliable source to monitor the extent of forest cover loss around the world. Using this information, a journalist can do a before-and-after story or delve into further investigation, bringing in the context, cause and effect. For instance, Making Sense of Amazon Deforestation Patterns, a four-part story by NASA Earth Observatory, extensively uses satellite images to show more than a sixth of the forest that once existed in the 1970s has been cleared over the past few decades.
Similarly, an article in Space.com in January 2021 highlights how satellite imagery has actually helped to reduce deforestation across Africa. The article quotes Global Forest Watch research to show that in 22 countries in Africa, organizations subscribed to a free service from GFW that sends out alerts based on up-to-date satellite data and took actions based on those alerts. Anyone can sign up for these automated warnings that send high-resolution satellite data and alert messages when there is a drop in forest cover.
Besides the vast data, analysis and reports it provides, GFW, which is produced by the World Resource Institute, includes interactive charts and maps that summarize key statistics about global forests, including global rankings, rates of forest change, forest extent and drivers of deforestation. The data is available by country, and is easy to read, customize and download.
Further, GFW’s GLAD and RADD deforestation alerts are particularly interesting since they can help us track changes in forests almost in real time through satellite imagery. GLAD uses imagery from NASA’s Landsat satellites to flag areas where the forest canopy has been disturbed. The algorithm, which runs on Google Earth Engine, analyzes the most recent images and compares them to historical data to determine where trees have been lost.
In 2020, GFW announced that Earthimaging company Planet will provide free public access to five-meter resolution satellite imagery covering the entire tropical forest region, to be updated monthly. This is significant since Planet is the only organization — public or private — that has the capability to image every inch of Earth 24/7.
GFW’s RADD alerts are built from the world’s first global, freely available synthetic aperture radar data from ESA’s Sentinel-1 satellites and can detect changes faster than ever, since they can see through clouds and even at nighttime. The satellites revisit each spot on the globe about once a week. When the software detects a change — when trees have disappeared from a particular spot since the satellite last looked at it — the subscriber gets an alert, and a color-coded spot shows up on the map of the affected areas.
Keep an eye on NASA and ESA websites for regular alerts and announcements. Data from the GEDI lidar sensor onboard the International Space Station is also an interesting tool for measuring deforestation and topography changes.
URBANIZATION
More than half the world’s population lives in cities today, which is estimated to rise by another 2.5 billion by 2050. This is leading to immense pressures on urban infrastructure and exacerbating weather-related disasters like flooding. Unplanned urbanization also leads to land-use changes, creates a rise in temperatures in cities, depletes groundwater resources, causes loss of green cover, and increases air pollution due to traffic movement.
For instance, the Indian city of Chennai faced an acute water crisis in the summer of 2019. A set of Sentinel imagery from ESA of the city’s primary rain-fed reservoir, Puzhal Lake, shows roughly full capacity in 2018 while the June 2019 image shows an area of parched land. Further analysis shows this has happened largely due to unplanned construction, which turned the city into a concrete jungle.
In an interesting study, NASA research last year found that fewer cars on the roads during the April-May COVID-19 lockdown period led to hotter surface temperatures. NASA used Landsat and ECOSTRESS, which is a sensor on the International Space Station, to measure the land surface temperature variations on May 22, 2020, during the full lockdown period over an area centered on the Great Mall in Milpitas, California.
DESERTIFICATION
Desertification has been described as “the greatest environmental challenge of our time” by the UN Convention to Combat Desertification. Desertification is closely linked to deforestation and urbanization, since it swallows arable land, affecting the livelihoods of millions. UNCCD estimates that around 12 million hectares of productive land are lost to desertification and drought each year, and the pace has accelerated by 30-35 times the historical rate.
In India, a report from the Indian Space Research Organization found that land degradation is estimated at 96 million hectares, or nearly 30% of the country’s land.
Spending some time on NASA’s Earth Observatory website, ESA’s Copernicus Land Monitoring Service, World Resources Institute, and/or The Nature Conservancy could yield interesting satellite data to use in stories about land degradation and desertification in various parts of the world.
OCEAN MONITORING
Sea surface temperature can tell a lot about what’s happening in and around the oceans. A key indicator for sea level rise, sea temperature also influences the behavior of fish, coral bleaching and weather along the coasts.
The U.S. National Oceanic and Atmospheric Administration’s World Ocean Database is the world’s largest collection of uniformly formatted, publicly available ocean profile data. One can use the WOD select retrieval system to search the dataset by specific parameters (such as date, geographic area, probe type) and measured variables. You can view a dataset distribution map, set your search criteria, and download a custom dataset.
Satellites also help monitor the color of the water across the oceans, which gives information on the impact of floods along coastlines, detects river plumes and locates harmful algae. Satellites also help in capturing occurrences like coral bleaching, which can indicate dying corals. For instance, images from the Copernicus Sentinel-2A satellite captured on June 8, 2016 and Feb. 23, 2017 show coral turning bright white on the Great Barrier Reef.
On May 19, 2021, the Allen Coral Atlas released the world’s first satellite-based global coral reef monitoring system that uses detailed habitat maps of all the coral reefs in the world to detect bleaching.
THEN THERE’S PLASTIC
Over 8 million metric tons of it is dumped into the oceans each year, and by 2050, ocean plastic will outweigh all of the oceans’ fish. In 2020, ESA’s Earth Observation Tracking of Marine Debris in the Mediterranean Sea from Public Satellites project introduced an innovative approach to detect marine litter in coastal waters around the world. The Sentinel-2 satellites can distinguish plastic debris from other materials, as well as the concentration, movement and even sometimes origin with high accuracy.
Additionally, sources like Tracking of Plastic in Our Seas, Ocean Plastic Tracker, Greenpeace and World Wildlife Fund are good places to keep an eye on the developments on this front.
EMISSIONS AND AIR POLLUTION
The World Health Organization estimates that around 91% of the world’s population lives in places where air quality levels exceed safe limits and account for an estimated 4.2 million deaths per year.
Forecasters use data from NASA’s Land, Atmosphere Near real-time Capability for EOS (Earth Observing System) to improve some local and national air quality forecasts. Users can visualize imagery related to Air Quality in NASA Worldview. Bookmark NASA WorldView and Earth Observatory blogs for updated information about tracking pollution from space.
Launched in 2018, ESA’s Copernicus Sentinel- 5P is the best-in-class satellite for monitoring air-polluting gases that are invisible to the human eye, including ozone, sulfur dioxide, nitrogen dioxide, carbon monoxide, methane and formaldehyde, as well as aerosols in the Earth’s atmosphere. For instance, images taken by the Sentinel-5P satellite show that air pollution drastically decreased in China during the lockdown period in February 2020, but now has rebounded.
METHANE MONITORING
Methane monitoring warrants a special mention, since its ability to trap heat in the atmosphere is 25 times that of CO2.
According to a UN assessment, it is possible to reduce nearly half of the roughly 380 million metric tons of methane released by human activities annually by the end of this decade, which will help cut nearly 0.3 degrees Celsius (32.54 F) of warming by the 2040s. The easiest way to do so is by fixing leaky pipelines, stopping deliberate releases such as venting unwanted gas from drilling rigs, and other actions in the oil and gas industry, and capturing fumes from rotting materials in landfills, the UN report says.
A climate reporter can always be on a hunt for methane leaks by major industries. Over the past five years several satellites have been launched — both public and private — that can help us know their precise locations. In addition to ESA’s Sentinel-5P, the Italian Space Agency launched PRISMA in 2019, while Canadian private company GHGS has launched three satellites in the past five years.
Satellites found that despite the pandemic, the number of methane hot spots has soared 32% over the past year. According to a report in The Washington Post, Paris-based firm Kayrros compared the first eight months of 2019 to the same period in 2020 and found that methane leaks from oil and gas industry hot spots climbed even higher in Algeria, Russia and Turkmenistan, growing by more than 40%. According to Kayrros, the largest contributors to rising methane releases were the United States, Russia, Algeria, Turkmenistan, Iran and Iraq.
A new policy briefing published in association with the COP26 Universities Network in May identifies Earth Observation satellites as a “critical tool for monitoring the causes and effects of climate change.” It finds that satellite data is also vital for holding governments accountable in meeting goals brokered in the Paris Accord in 2015 to lower greenhouse gas emissions and reduce global warming.
For journalists filing climate and environmental stories, knowing how to access, assess and present their data is becoming more vital by the year
Anusuya Datta is a Canada-based writer/journalist who has spent the past decade writing about data and digitalization with a special interest in connecting technology with sustainability issues and social causes. Her work has appeared on various platforms including Geospatial World, SpaceNews and The Wire report.
Featured photo from Getty Images / BlackJack3D.
