What is methane? |
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Methane (CH4) is a potent greenhouse gas with a warming potential about 30 times that
of carbon dioxide (CO2). It also has a shorter atmospheric life than carbon dioxide,
which means that once methane is emitted, it does not stay in the atmosphere as long as
carbon dioxide does. Methane's enormous warming potential means it is having an outsize
short-term effect on climate change, but due to its short atmospheric life, reducing
methane emissions could make a big impact.
Why is it important to measure methane?In order to reduce methane emissions in the Greater Toronto Area, we must first know two things: how much methane we are emitting, and where methane emissions are coming from. The City of Toronto's latest Sector-Based Emissions Inventory measures emissions in terms of CO2 equivalent (CO2e), which lumps multiple sources of emissions, including methane, into one category. This means that the City of Toronto does not include specific numbers or targets related to methane in its TransformTO net-zero strategy, so public data about methane emissions in the GTA is scarce. |
Credit: Smithsonian Environmental Research Centre |
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In 2021, we published the
FLAME-GTA inventory, a summary of methane emissions in the GTA based on
our own measurements and research. The FLAME-GTA inventory provides a reasonably accurate estimate
of how much methane the GTA is emitting, as well as which sectors methane emissions are coming from.
We regularly take methane measurements using a mobile laboratory consisting of a weather station and gas analyzer mounted on a bicycle trailer. We cycle around the city with the lab and update this website with real-time atmospheric data. These measurements sometimes alert us to new sources of methane, which makes our estimates of overall methane emissions in the GTA more accurate. |
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LGR Ultraportable Greenhouse Gas Analyzer |
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| The LGR Ultraportable Greenhouse Gas Analyzer (UGGA) is developed by Los Gatos Research. It simultaneously measures concentrations of methane, carbon monoxide, carbon dioxide, and water vapour in the ambient air. The sampled air is flushed into the instrument via a pump and concentrations are displayed in real time. The response time of this instrument is 10 seconds and the quoted repeatability is 3 ppb over a 1 second integration period for methane. | ||
EM27/SUN Fourier Transform Spectrometer |
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| The EM27/SUN Fourier Transform Infrared Spectrometer (FTIR) is made by Bruker. It records an interferogram of direct sunlight and a Fourier transform is then performed in order to determine the chemical composition of the atmosphere between the sun and the spectrometer. | ||
G1301 Picarro Cavity Ring-Down SpectrometerThe G1301 Cavity Ring-Down Spectrometer (CRDS) is developed by Picarro. The instrument measures simultaneously concentrations of methane, carbon dioxide, and water vapour in the ambient air and its quoted repeatability is 1.5 ppb over a 30 sec period for methane. AIO 2 Weather StationThe AIO 2 Sonic Weather Sensor is developed by Met One Instruments and includes a built-in compass used for automatic alignment of the wind sensor. In addition to the the wind speed and direction, the sensor also outputs temperature, humidity, and barometric pressure. Airmar WX220 Weather StationThe Airmar weather station has an internal GPS which provides location and velocity parameters. It measures wind speed and direction with ultrasonic sensors and computes the wind velocity relative to the ground by performing vector math on the apparent wind and velocity of the weather station. It also outputs temperature, heading, pressure and more. |
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