Climate satellite sensing

 By Michelle Leslie

Traveling at speeds of over 7 km per second, she makes a journey around our planet every 90 minutes tracking atmospheric footprints through wavelengths. Meet Claire

The size of a microwave oven, Claire is a satellite on a mission to cut greenhouse gases. She spends her days high in the sky tracking global carbon dioxide and methane outputs as she orbits, providing real-time data on climate-changing emissions. These two greenhouse gases alone account for over 90% of all global emissions.
According to Stephane Germain, chief executive officer of GHGSat, the company responsible for Claire “it’s a whole new way for industrial operators to better understand their emissions anywhere in the world thereby controlling and ultimately reducing them”.

GHGSat’s demonstration satellite GHGSat-D, nicknamed “Claire”, successfully launched at 23:56 EDT on 21 June 2016, and reached its planned orbit less than 30 minutes later (

The science of spectroscopy

Through a process known as spectroscopy, the unique fingerprint of a gas can be identified. The satellite contains a sensor, also known as a spectrometer, that measures the reflected sunlight over the earth’s surface. The reflected radiation passes through the atmosphere and interacts with gas molecules such as methane and carbon dioxide. These gases absorb radiation at particular wavelengths, allowing the satellite’s sensor to measure the presence of the gas and the quantity over a specific area. “The fundamental idea of how gases absorb light at different wavelengths was really developed by NASA and the Japanese Space Agency“, explained Germain. “They are the real pioneers in this, and all of our work has been built on that”.

Mass spectrometry is allowing scientists to look very closely at a sample and see what's inside (NASA)

NASA launches OCO-3

NASA recently launched OCO-3, which will be installed at the International Space Station. The satellite will look at how plant activity is affected by the natural carbon cycle to determine how plants interact with weather conditions and the impact this has on carbon absorption rates. According to NASA, on average, 50% of global carbon emissions are removed thanks to our plants’ and oceans’ natural abilities to suck up CO2. This ability to remove greenhouse gases, however, is dependent on large scale atmospheric events.
“During El Niño years in the tropics, plants experience drought, and under this stress they can’t remove as much carbon from the atmosphere versus during a typical year”, said Dr. Annmarie Eldering, project scientist for OCO-3, NASA.
With economic development, climate change and large-scale urbanization, OCO-3 will be able to provide vital information on how meteorological elements may influence future global emissions profiles. It is an important step to reducing GHG outputs by streamlining data across countries, giving an accurate picture of global carbon emissions.
According to Eldering, measurement systems installed at power plants can provide real-time, accurate data. “You can get really detailed information”, she explains, “but not every country or place on the earth has the same type of approach”.

Nasa's launch of OCO-3 will explore how plants interact with weather changes and how this affect carbon absorption (

While NASA will be monitoring profiles from outer space, satellites like Claire, closer to the Earth’s surface, can measure hundreds of locations in seconds, finding leaks that often go undetected. It’s this unique ability to map out emissions that provides an opportunity to reduce carbon footprints.

Meet MethaneSAT

“When we started looking at this issue, we realized no one really had a full clear picture”, explained Jon Coifman, Communications Director of the Environmental Defense Fund. “Companies – even while well intentioned – didn’t realize the extent of the problem”.
Reducing emissions through remote sensing is what the Environmental Defense Fund is hoping to accomplish with MethaneSAT, a new satellite that delivers global, high-resolution coverage of methane emissions from oil and gas facilities. Data from this satellite could help to significantly slash oil and gas methane emissions up to 45% by 2025 – the equivalent environmental benefit of closing one-third of the world’s coal-fired power plants.

Data from MethaneSAT will help measure methane pollution from oil and gas facilities worldwide with both broad scope and exacting precision (

A collaboration between Harvard University and the Smithsonian Astrophysical Observatory, MethaneSAT uses a highly sensitive spectrometer, similar to GHGSat. Based on years of scientific research, the innovation will be able to detect methane emissions as small as two parts per billion. The data collected will be combined with weather information in order to determine the location and quantity of methane emissions.
“The satellite is designed to provide a working tool for both companies and countries, regulators and industry; to have a transparent, reliable and robust data picture of what is happening on the ground”, stated Coifman. “Our aim is to provide people with the ability to see where companies and countries have made commitments and that progress is happening”.
From Canada’s oil sands to China’s coal mines and power plants in Europe, Claire has mapped out thousands of gas profiles during her time in the sky with more than 4,000 measurements and counting, analyzing both industrial and natural sources around the world.

Future carbon markets

With a global carbon market skyrocketing in value and worth close to $100 billion dollars, this technology offers up big benefits to business while providing vital information on pollution outputs, aiding in carbon-cutting solutions and providing a more sustainable approach to resource management. GHGSat recently announced that Iris will soon join Claire in orbit, making her launch in August 2019, with a dozen or so more climate-sensing satellites set to follow suit in the next few years.

Iris, which is GHGSat’s second satellite, will carry an instrument which incorporates almost three years of lessons learned from flying GHGSat’s demonstration satellite Claire (GHGSat)

Meanwhile, MethaneSAT is on track to launch in the second half of 2021, and OCO-3 will start collecting data sometime in June 2019 with information expected to be available by the end of the summer.

READ MORE: Satellites find sustainable energy in cities by Benjamin Plackett

about the author
Michelle Leslie
Alberta, Toronto and now Ottawa. Meteorologist, Journalist & Munk School Of Global Affairs Fellow.