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Tracking emissions by satellite

June 20, 2025 By EarthWise Leave a Comment

Carbon dioxide and nitrogen oxides are two of the most problematic human-generated air pollutants that negatively impact air quality, the climate, and human health. Satellites are an important tool for monitoring emissions of these pollutants, but they have limitations. For the most part, satellites have limited spatial resolution, meaning that they can’t reliably narrow down the source of emissions sufficiently to pin down a specific location such as a power plant.

Until now, there have been no instruments that can detect both carbon dioxide and nitrogen oxide simultaneously with high spatial resolution. Often just nitrogen oxide measurements are made, and carbon dioxide levels estimated based on the fact that both are emitted together with typical ratios.

A German research team from the Max Planck Institute and the Heidelberg Institute have developed a technology for the EnMAP environmental satellite to detect both gases with an unprecedented spatial resolution of 30 meters. Data from the satellite makes it possible to track multiple sources of emission plumes over several tens of kilometers.

The EnMAP system was originally designed for remote sensing of land surfaces. The new research demonstrates that reliable measurements of trace gases are possible even with an instrument not specifically designed for atmospheric observations. When using it, it’s possible to determine the distribution of carbon dioxide and nitrogen oxide in emission plumes from individual power plants. The ability to measure both gases individually means that conclusions can be drawn about the technology, efficiency, and operating mode of the systems being measured.

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German satellite measures CO2 and NO2simultaneously from power plant emissions for the first time

Photo, posted September 19, 2020, courtesy of Sandor Somkuti via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electric trains are healthier

May 7, 2025 By EarthWise Leave a Comment

The majority of commuter trains in the U.S. are powered by diesel fuel. This is despite the fact that electric trains are quieter, more reliable, and produce fewer greenhouse gases than diesel locomotives. A new study has found that electric trains are healthier for passengers as well.

Caltrain carries millions of passengers a year along a 47-mile route between San Francisco and San Jose. It is the busiest commuter rail system in the western U.S. Over a six-week period beginning in August 2024, Caltrain retired all 29 of its diesel locomotives and replaced them with electric trains.

As the process began, an environmental engineering and environmental health professor at UC Berkeley noticed the rapid change in the air aboard the trains and decided to study its potential health impacts. With the support of Caltrain, he installed black carbon detectors aboard the trains and tracked the improvements in air quality as old diesel locomotives were being replaced by new electric trains.

Statistical analysis of the reduction in black carbon exposure achieved by the change predicted a reduction in excess cancer deaths by 51 per million people for passengers and 330 per million people for train conductors. EPA policy states that any exposure that increases the average individual’s cancer risk by more than one per million is considered unacceptable.

In the context of the whole U.S. where millions of people commute by rail every day, the study predicts that hundreds of cases of cancer could be prevented each year. California has long-term plans to electrify most of its rail systems. The study indicates that the process shouldn’t be carried over the next 25 years but rather be sped up.

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Electric trains are quieter, more reliable than diesel. New study finds they’re healthier, too.

Photo, posted September 4, 2024, courtesy of J. Kehoe via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Environmental DNA | Earth Wise

August 5, 2022 By EarthWise Leave a Comment

Marine protected areas are sections of the ocean where governments place limits on human activity. They are intended to provide long-term protection to important marine and coastal ecosystems. MPAs are important because they can protect depleted, threatened, rare, and endangered species and populations.

In January 2020, the Republic of Palau in the western Pacific Ocean created one of the world’s largest marine protected areas. The Palau National Marine Sanctuary covers 80% of the country’s economic zone and prohibits all extractive activity like fishing and mining over a 183,000 square mile area in order for the island nation to ensure its food security and grow its economy in the face of climate change.

The Marine Sanctuary is an ambitious enterprise. The question is how Palau can evaluate whether and how well it is working?

A team of scientists from Stanford University and Palau-based colleagues are making use of Environmental DNA – or eDNA – technology to monitor the large-scale marine protected area. eDNA is the cells, waste, viruses, and microorganisms that plants and animals leave behind. Samples of marine eDNA effectively provide a fingerprint of the organisms that have recently passed through the water in a given area. This gives scientists a way to assess an ecosystem’s biodiversity and keep track of the types of species inhabiting a specific area. Using eDNA, it is possible to keep track of all the organisms that live below the surface and learn about things we can’t even see.

The team has embarked on a program of periodic sampling of the waters off Palau and hope to be able to monitor the results of establishing the Marine Sanctuary.

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eDNA: Bringing biodiversity to the surface

Photo, posted June 12, 2013, courtesy of Gregory Smith via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Permafrost Thaw | Earth Wise

March 18, 2022 By EarthWise Leave a Comment

We’ve talked about permafrost before. It is the frozen soil, rock, or sediment piled up in the Arctic that has been there at least for two years but, for the most part, for millennia or even over a million years. Permafrost holds the carbon-filled remains of vegetation and animals that froze before they could start decomposing. Estimates are that there are nearly 2,000 billion tons of carbon trapped in Arctic permafrost. To put that in perspective, annual global carbon emissions are less than 40 billion tons.

Keeping all that carbon frozen plays a critical role in preventing the planet from rapidly heating. The ongoing warming of the Arctic is causing the subsurface ground to thaw and release long-held carbon to the atmosphere.

Scientists from Europe and the US are working together to better track permafrost carbon dynamics. They are trying to understand the mechanisms that lead to abrupt thaws in the permafrost that have taken place in some locations. These rapid thawing events are not well understood. Researchers are also studying the effects of the increasingly frequent wildfires in the Arctic on the permafrost.

Researchers are using satellites to better understand the effects climate change is having on the Arctic environment and how these changes, in turn, are adding to the climate crisis. Permafrost cannot be directly observed from space, so that its presence has to be inferred from measurements like land-surface temperature and soil moisture readings. Terrestrial observations are also necessary for understanding how greenhouse gases – both CO2 and methane – are being emitted from the Arctic.

Thawing permafrost is a ticking timebomb for the environment that demands the growing attention of the scientific community.

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Permafrost thaw: it’s complicated

Photo, posted January 24, 2014, courtesy of Brandt Meixell / USGS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Batteries On Wheels | Earth Wise

December 24, 2021 By EarthWise Leave a Comment

Transportation accounts for nearly a quarter of the direct carbon dioxide emissions coming from burning fuel. As a result, electrification of transport is one of the major ways we can reduce emissions. Increasing the number of electric vehicles over time is essential for meeting emissions targets.

But electric vehicles have the potential to do more than deliver emissions reduction; they can also provide other energy services.

More and more electric cars provide over 200 miles of driving range, but most cars are actually driven no more than 30 miles a day. As a result, the fleet of electric cars represents a huge bank of energy stored in battery packs and mostly sitting around unused. This presents an opportunity to leverage this resource.

Car battery packs could be used to absorb excess renewable energy generated in the middle of the day (for example from solar installations) or at night (from wind farms) and potentially then to export stored energy to power homes and support the grid. This energy system is known as V2G, or vehicle-to-grid technology.

The University of Queensland in Australia has launched a unique international trial to see if the spare battery capacity in vehicles could be used for these purposes. The university has partnered with Teslascope, which is an online analytics platform used by Tesla owners to track the performance of their cars. Tesla owners wishing to be part of the study authorize the collection of their data and, in turn, receive a free 12-month subscription to the Teslascope service. The study will collect data from Tesla owners in Australia, the US, Canada, Norway, Sweden, Germany, and the UK.

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Can EV spare battery capacity support the grid?

Photo, posted February 8, 2009, courtesy of City of St Pete via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Radar Satellites And Hazard Mitigation | Earth Wise

May 26, 2021 By EarthWise Leave a Comment

Scientists have concluded that the changing climate is primarily the result of increased human-caused greenhouse gas emissions. Some of the effects of global climate change include melting glaciers, warming oceans, intensifying storms, and rising seas.

Another consequence of global climate change is natural disasters like floods and wildfires. Climate change is increasing the frequency and severity of wildfires and increasing the odds of record-breaking floods in many parts of the United States and all around the world.

As a result, scientists in Australia have turned to technology for better assistance in keeping tabs on these climate change-driven natural disasters. Researchers from Curtin University in Perth, Australia have found that satellites can improve the ability to detect, monitor, prepare for, and withstand natural disasters, including floods, wildfires, and earthquakes.

The research team used Synthetic Aperture Radar (SAR) data, which was acquired by the European Space Agency Sentinel-1 satellite. The researchers also used data acquired by other satellites to evaluate these Australia-specific case studies.

According to the researchers, SAR data provides remote monitoring capabilities of Earth’s surface around the clock and in all weather, which is something that traditional optical Earth Observation (EO) imagery cannot do. The ability to function through fog, clouds, rainfall, and smoke is what makes SAR so valuable.

The research team says that the data can be used to improve how people track and respond to natural disasters, by precisely mapping topography, tracking movements of the ground, and mapping damage to infrastructure.

As the climate continues to change, the ability to mitigate hazards like floods and wildfires will be increasingly important.

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Radar satellites can better protect against bushfires and floods

Photo, posted May 11, 2007, courtesy of Bert Knottenbeld via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hurricanes Are Slowing Down

July 17, 2018 By EarthWise Leave a Comment

According to a new study recently published in the scientific journal Nature, some hurricanes are moving slower and spending more time over land, which is leading to catastrophic rainfall and flooding. The speed at which hurricanes track along their paths – known as translational speed – can play a major role in a storm’s damage and devastation. 17