Tag Archives: Science

Tracking CO2 emissions from space could help support climate agreements

NASA’s Orbiting Carbon Observatory (OCO-2) satellite can make precise measurements of global atmospheric carbon dioxide (CO2) from space. (NASA/JPL-Caltech)

Ray Nassar, University of Toronto

The central objective of the Paris Agreement is to limit Earth’s warming to well below 2 C above pre-industrial levels, but preferably 1.5 C.

This challenging task will require policies and tools to enable every sector of society to drastically reduce greenhouse gas (GHG) emissions to eventually reach net-zero.

Enacting the most effective and efficient strategies to reduce emissions starts with knowing in detail where, when and how much of these greenhouse gases we are emitting, followed by implementing emission reduction policies and tracking our progress.

Is it possible to track carbon dioxide (CO2) emissions and emission reductions from space? New research from my group shows that it is.

Why CO2 matters

CO2 is the primary greenhouse gas driving climate change. Burning fossil fuels for electricity generation, heating buildings, industry and transportation has elevated the CO2 in our atmosphere well beyond natural levels.

Currently, CO2 emission reporting is mainly done by accounting for the mass of fossil fuels purchased and used, then calculating the expected emissions — not actual atmospheric CO2 measurements. The finer details about exactly when and where the emissions occurred are often not available, but more transparent monitoring of CO2 emissions could help track the effectiveness of policies to reduce emissions.

Today GPS satellites help us to get around, meteorological satellites track weather systems and communication satellites relay TV, internet and telephone signals. It is time we use satellites to help tackle the biggest challenge that humanity has ever faced — climate change.

Satellites for measuring CO2

A global network of ground-based CO2 measurements began in 1957 and now consists of over one hundred stations around the world. Accurate and precise measurements from these stations have revealed a lot about changes in global atmospheric CO2 and Earth’s overall carbon cycle, but we can’t place these stations everywhere on Earth.

Satellites can observe the entire planet. Those that measure CO2 in the lower atmosphere near Earth’s surface (where CO2 emissions and CO2 uptake by plants happens) first began making measurements in 2002. Since then, they have been getting better and better at doing it, but there have been setbacks along the way.

About a decade of effort by NASA went into developing the Orbiting Carbon Observatory (OCO) satellite to make precise measurements of atmospheric CO2 across the Earth.

NASA's OCO undergoing development prior to launch
NASA developed the Orbiting Carbon Observatory satellite to make precise measurements of atmospheric CO2 across the Earth. (NASA/JPL), Author provided

In 2009, OCO was lost due to a launch problem. After sustained advocacy for a rebuild of this important climate mission, NASA secured new funding to launch the OCO-2 satellite in 2014 and OCO-3 to the International Space Station in 2019.

The OCO missions were designed to improve our understanding of vegetation’s CO2 absorption, also known as the land carbon sink. But what about fossil fuel CO2 emissions?

A new way to verify CO2 emissions

In 2017, I led a research team that published the first study showing that we can quantify CO2 emissions at the scale of an individual power plant using OCO-2 observations.

Since OCO-2 was not designed for this purpose, its coverage and infrequent visits were inadequate for operational global CO2 emission monitoring, but we can still quantify emissions in select cases when the satellite passes close enough and gets a good cloud-free view.

OCO-3 is very similar to OCO-2, but has an additional pointing mirror that enables it to better map CO2 around targets of interest like the Bełchatów Power Station in Poland, Europe’s largest fossil fuel burning power plant and CO2 source.

A Power Station
Bełchatów Power Station, Europe’s largest fossil fuel burning power plant. (Shutterstock)

With ten clear views of CO2 emission plumes from Bełchatów imaged by OCO-2 and OCO-3 from 2017-2022 analyzed in our new study, we were able to determine emissions on those days.

European power plants report hourly power generation but only annual CO2 emissions. Power generation fluctuates with electricity demand and generating unit shutdowns (for maintenance or decommissioning) and CO2 emissions are expected to exhibit proportional fluctuations.

We confirmed this using OCO-2 and OCO-3 in our recent paper, which showed that satellite observations can track changes in facility-level CO2 emissions. This means that satellites can be used to verify (or refute) reported CO2 emission reductions that result from climate change mitigation — like mandated efficiency improvements, carbon capture and storage technology, etc.

OCO-3 observations of a CO2 emission plume from the Bełchatów Power Station in Poland on April 10, 2020 overlaid on Google Earth imagery.
A plume of high CO2 resulting from coal burning is evident down wind from the Bełchatów Power Station in OCO-3 observations. (Ray Nassar), Author provided

Emissions monitoring for the Paris Agreement

Our approach can be applied to more power plants or modified for CO2 emissions from cities or countries with OCO-2 and OCO-3. We can also try integrating the satellite observations with CO2 monitoring from the ground or aircraft.

While we are already working on this, advances will only be incremental until the launch of the European Commission-funded Copernicus Anthropogenic CO2 Monitoring Mission or “CO2M”. CO2M is comprised of two satellites, aiming to launch in late 2025.

These satellites will provide about 50 times as much coverage as OCO-2 and OCO-3 combined and will form the space component of Europe’s system for CO2 emissions Monitoring, Verification and Support (MVS).

CO2M will be a major advance, but just like successful global climate action, requires contributions from many countries. The long-term robust operational global monitoring of GHG emissions will need a constellation of satellites contributed by multiple countries as part of an integrated global observing system.

Hopefully, with new, more detailed and transparent tracking of human-caused greenhouse gas emissions to assess and guide us toward the most effective policies, society can achieve the emission reductions needed to reach net-zero in time.

Ray Nassar, Research Scientist at Environment and Climate Change Canada (ECCC), Adjunct Professor in Atmospheric Physics, University of Toronto

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Scientists discover five new species of black corals living thousands of feet below the ocean surface near the Great Barrier Reef

Researchers discovered five new species of black corals, including this Hexapathes bikofskii growing out of a nautilus shell more than 2,500 feet (760 meters) below the surface. Jeremy Horowitz, CC BY-NC

Jeremy Horowitz, Smithsonian Institution

The Research Brief is a short take about interesting academic work.

The big idea

Using a remote-controlled submarine, my colleagues and I discovered five new species of black corals living as deep as 2,500 feet (760 meters) below the surface in the Great Barrier Reef and Coral Sea off the coast of Australia.

Black corals can be found growing both in shallow waters and down to depths of over 26,000 feet (8,000 meters), and some individual corals can live for over 4,000 years. Many of these corals are branched and look like feathers, fans or bushes, while others are straight like a whip. Unlike their colorful, shallow-water cousins that rely on the sun and photosynthesis for energy, black corals are filter feeders and eat tiny zooplankton that are abundant in deep waters. https://www.youtube.com/embed/MYncyEIDr10?wmode=transparent&start=0 The team of researchers collected 60 specimens of black corals over 31 dives using a remotely operated submarine.

In 2019 and 2020, I and a team of Australian scientists used the Schmidt Ocean Institute’s remotely operated vehicle – a submarine named SuBastian – to explore the Great Barrier Reef and Coral Sea. Our goal was to collect samples of coral species living in waters from 130 feet to 6,000 feet (40 meters to 1,800 meters) deep. In the past, corals from the deep parts of this region were collected using dredging and trawling methods that would often destroy the corals.

Our two expeditions were the first to send a robot down to these particular deep-water ecosystems, allowing our team to actually see and safely collect deep sea corals in their natural habitats. Over the course of 31 dives, my colleagues and I collected 60 black coral specimens. We would carefully remove the corals from the sandy floor or coral wall using the rover’s robotic claws, place the corals in a pressurized, temperature-controlled storage box and then bring them up to the surface. We would then examine the physical features of the corals and sequence their DNA.

Among the many interesting specimens were five new species – including one we found growing on the shell of a nautilus more than 2,500 feet (760 meters) below the ocean’s surface.

A robotic arm grabbing a thin coral off of a rock.
Researchers used the robotic arm of their rover to collect over 100 samples of rare corals and brought them up to the surface for further study. Jeremy Horowitz, CC BY-ND

Why it matters

Similarly to shallow-water corals that build colorful reefs full of fish, black corals act as important habitats where fish and invertebrates feed and hide from predators in what is otherwise a mostly barren sea floor. For example, a single black coral colony researchers collected in 2005 off the coast of California was home to 2,554 individual invertebrates.

Recent research has begun to paint a picture of a deep sea that contains far more species than biologists previously thought. Considering there are only 300 known species of black corals in the world, finding five new species in one general location was very surprising and exciting for our team. Many black corals are threatened by illegal harvesting for jewelry. In order to pursue smart conservation of these fascinating and hard-to-reach habitats, it is important for researchers to know what species live at these depths and the geographic ranges of individual species.

A large, white, tree-like coral underwater.
Black corals don’t form large reefs like shallow corals, but individuals can get quite large – like this Antipathes dendrochristos found off the coast of California – and act as habitat for thousands of other organisms. Mark Amend/NOAA via Wikimedia Commons

What still isn’t known

Every time scientists explore the deep sea, they discover new species. Simply exploring more is the best thing researchers can do to fill in knowledge gaps about what species live there and how they are distributed.

Because so few specimens of deep-sea black corals have been collected, and so many undiscovered species are likely still out there, there is also a lot to learn about the evolutionary tree of corals. The more species that biologists discover, the better we will be able to understand their evolutionary history – including how they have survived at least four mass extinction events.

What’s next

The next step for my colleagues and me is to continue to explore the ocean’s seafloor. Researchers have yet to collect DNA from most of the known species of black corals. In future expeditions, my colleagues and I plan to return to other deep reefs in the Great Barrier Reef and Coral Sea to continue to learn more about and better protect these habitats.

Jeremy Horowitz, Post-doctoral Fellow in Invertebrate Zoology, Smithsonian Institution

This article is republished from The Conversation under a Creative Commons license. Read the original article.