A year of CO2
In 2014, NASA launched the Orbital Carbon Observatory (2) satellite, OCO-2. Its job is to measure CO2 emissions around the world at fine scales, showing where the true sources and sinks of carbon dioxide are around the world.
CO2 is a greenhouse gas. When the sun warms earth’s surface, that heat is released as infrared radiation (infrared light). CO2 absorbs some wavelengths of infrared light and therefore acts like a blanket; as the sun’s energy tries to leave the planet, CO2 grabs it and converts it back to heat.
CO2 is released by all sorts of processes. Right now, burning fossil fuels is by far the largest source on Earth. A secondary source is land use changes; releasing carbon locked in soils, wetlands, or forests to the atmosphere.
Over the last 200 or so years, humanity has released enough extra CO2 into the atmosphere to warm the planet by about 1 degree C - like throwing an extra thin blanket on top of the planet to keep the heat in.
This data from OCO-2 shows a year of CO2 around the world. There are many trends reflected. There is more land area in the northern hemisphere than the southern hemisphere, so every year during northern hemisphere summer when trees form their leaves and other plants grow, CO2 drops. Superimposed on that trend, there is a long term trend of increasing CO2, reflecting the amount released by humans during the year.
OCO-2 and systems like it can spot CO2 sources at fine scales: literally measuring each city block. As a consequence, its measurements will be key in implementing the agreement just struck in Paris at the latest UN organized conference to deal with climate change.
An agreement struck today sets the world on a possible path to limiting CO2 emissions enough to keep warming under 2 degrees C, with negotiable goals for the future of lowering emissions enough to aim for 1.5 degrees C. While that temperature change would still be a substantial disruption to the planet, the hope is it would be less than catastrophic to most of the people on Earth.
Satellites like OCO-2 can verify how much carbon is coming out of each source. Having measurements like this make it impossible for countries to cheat on this agreement without the rest of the world knowing it. Humanity has spent 200 years treating the atmosphere as a waste dump, but now that we understand how hazardous that behavior is, we’ve developed tools like this to track who is dumping what into our air.
The agreement at the #COP21 conference is a big, big deal. Climate Change is a geologic issue; humanity has become a force that can impact this planet at a level that threatens cities and nations. Finally in Paris today, an agreement between the nations of the world holds the promise of being a first step in controlling this impact. Now it needs to be accepted and expanded.
I felt nothing was more important than to show this OCO-2 data in another place with the agreement accepted by all the meeting nations today. This single year of data shows the problem. Hopefully now we’re on a path to at least limiting how big of a problem it is.
-JBB
Image credit: NASA/OCO-2 http://earthobservatory.nasa.gov/IOTD/view.php?id=87146&src=twitter-iotd











