Nature Reports Climate Change—Interview: David Crisp (Orbiting Carbon Observatory)

[OKIsItJustMe]

http://www.nature.com/climate/2009/0903/full/climate.2009.20.html

Q&A

Nature Reports Climate Change
Published online: 19 February 2009 | doi:10.1038/climate.2009.20

Interview: David Crisp

Due to launch 24 February, NASA's Orbiting Carbon Observatory (OCO) will measure carbon dioxide in the Earth's atmosphere with a precision high enough to detect the origin and fate of carbon emissions. Principal investigator David Crisp talks to Anna Barnett about hopes and expectations for the programme.

What can a dedicated carbon-monitoring satellite tell us that current monitoring programs can't?

From ground-based monitoring stations, we know that slightly less than half the carbon dioxide put into the atmosphere in the last 50 years has actually stayed there. But there aren't enough ground stations to tell us where the carbon sinks are. About a quarter is being absorbed by the oceans and by trees, but we don't know where the rest is going. Now, one might worry about whether these sinks will continue to be sinks. It'd be nice if we could study them and determine whether they're going to continue to do us this wonderful favour.

In space, we can observe the entire Earth using the same instrument. Because we're analysing sunlight we can't work at night, and we have trouble with clouds — we need clear skies to measure CO2 at the surface. We'll use modelling to adjust for this, but there will almost certainly be important gaps. The OCO will provide millions of additional measurements every two weeks, but we still need other techniques.

The OCO beat out 32 other proposals in a NASA contest for low-cost Earth science missions. What made it such a good buy?

One clear advantage was that it didn't require any inventions to make it work. In the 1990s NASA had been looking at measuring carbon dioxide with high-powered lasers that weren't yet practical for use in space. So in 2000, a group of us started looking for existing technologies. We decided to measure reflected sunlight in the near-infrared part of the spectrum — just slightly redder than the reddest red your eye can pick up — a different band than what's been used for a lot of Earth-monitoring science.

…

(Follow the link for the rest of this interview.)