#iamoco2

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

Orbital Carbon Observatory 2 to launch tomorrow morning

In February 2009, a rocket launched from Vandenberg airbase in California failed to separate into two sections appropriately, causing the satellite it was carrying to fail to reach orbit.

That satellite was the Orbital Carbon Observatory, what would have been a key piece in trying to understand and respond to climate change on Earth. Tomorrow morning, the “Orbital Carbon Observatory 2” spacecraft will attempt to lift off from Vandenberg on, well, a different type of rocket. That spacecraft can be seen sitting here on its Launchpad awaiting ignition.

The Orbital Carbon Observatory, or OCO-2, is meant to do something no other satellite has ever done; measure the sources and sinks of CO2, the main greenhouse gas being released by the burning of fossil fuels and land use changes.

This measurement is hugely important for enabling a response to climate change. Here’s the basic problem; we can make some estimates for how much carbon is released to the atmosphere by each country based on the amounts of fuel they consume and areas of forest that are burned, but that’s all they really are; estimates.

Calculating the carbon released by a simple activity like running a power plant is surprisingly complex. It depends on how much energy it takes to extract the fuel from the ground, how much energy it takes to transport the fuel, to process it, etc. It depends on how much carbon there is per square foot of forest, or of marshland, lost, even how much carbon is released by the cement used to form the roads.

These are very complex problems. Here’s an example; over the past few years, the U.S. has had a boom in natural gas production, causing several coal-driven power plants to shut down and be replaced with natural gas driven plants. However, these natural gas extractions are complicated; there is carbon lost during extraction and shipment that will go into the atmosphere. According to a simple calculation of how much fuel is burned the U.S. might have cut its carbon emissions by switching to gas, but it depends on how much fuel is lost at the source and that’s been really difficult to measure.

OCO-2 will measure that.

Similarly, during negotiations for how to respond to climate change, several nations have wanted to receive credits for carbon taken up by forests that expand or regrow on their shores, but how much carbon is being taken up by those forests and does that offset what is being released? That question depends on counting up the mass of every tree and figuring out what replanting trees does to the surrounding ecosystems, a very complicated problem.

OCO-2 will measure that.

OCO-2 will orbit the planet in a polar orbit, covering the entire planet once ever 18 days. As it goes, it will take fine-scale spectral measurements of the atmosphere, specifically measuring the abundance of carbon dioxide. It will tell us where carbon in the atmosphere is coming from and where it is going.

It’s going to be able to see how much carbon dioxide is coming out of a city, or out of areas with lots of power plants, or out of a burning virgin forest. It’s going to be able to see how much carbon dioxide is taken up by a growing forest and how much is being taken up by the oceans at different points.

We have already seen examples of countries claiming they are doing certain things to respond to climate change; OCO-2 will measure if that is actually true. One of the great things about the Landsat program and other satellite-based images is that it’s hard to hide from them; if people are burning forests illegally, Landsat sees them. OCO-2’s job is to do that with carbon dioxide. If a new power plant or gas extraction facility is releasing more CO2 than its supposed to, or if a country is burning more forest than it’s agreed to do, OCO-2 will measure that.

The loss of the first OCO satellite set back both climate negotiations and climate change response by several years. We needed this satellite in 2009 and we need it even more now. The launch can be followed online at the links below.

-JBB

Image credit: NASA http://www.nasa.gov/content/nasas-oco-2-satellite-on-the-launch-pad/#.U7HEwxYij1p

The first Delta II rocket to launch in over three years was assembled last week at Vandenberg Air Force Base, in preparation for tonight's OCO-2 launch. The Orbiting Carbon Observatory-2 satellite will perform the most detailed observations of carbon dioxide levels. The original satellite was launched in 2009, but a payload fairing malfunction caused the craft to fail to achieve Earth orbit.

The Delta II was once the United State Air Force's most reliable rocket. With the advent of the larger Delta IV and Atlas V, however, the Delta II has been phased out of service. Components for only five more rockets remain, with four being purchased by NASA. Flights in November 2014, 2015, and mid 2017 are on the books for the launcher, all of which will take place from Vandenberg. Florida's likely last Delta II launch was also the rocket's most recent, launching NASA's twin GRAIL satellites in October, 2011.