Science Technology Drive-By Technology Measures Exact CO2 Emissions With Infrared Sensors By Alex Davies Alex Davies Twitter Writer Macalester College Alex Davies is a technology journalist and the author of "Driven," an upcoming book about the self-driving car industry. Learn about our editorial process Updated October 11, 2018 Video screen capture. Livestream Share Twitter Pinterest Email Science Space Natural Science Technology Agriculture Energy Livestream/Video screen capture. Measuring CO2 emissions in Boston. Carbon emissions are hard to measure, especially on large scales. So when figures are given for how much CO2 a particular city, country or event pumps into the air, chances are they come from a calculation- an estimate- not an actual measurement. But a new technology from Picarro is making real numbers available by using infrared sensors operating out of a moving vehicle. As Google did for Street View, Picarro drives around places with hugely expensive equipment in the back of a truck. Gas-phase molecules, like CO2, have "unique near-infrared absorption spectrums" - wavelengths that can be detected accurately and in real time to produce "hyper-visual, three-dimensional maps" of carbon emissions. Here, CEO Michael Woelk explains how it works: To implement the technology, Picarro launched the City Carbon Project at the World Economic Forum meeting in Switzerland in late January. (Surprisingly, emissions during the event were lower than before or after it.) The next step is to bring City Carbon to more, bigger cities and events, enabling scientists and municipalities to have defensible numbers on CO2 levels. So now that the technology is available, Woelk, says, the only question is: "Do you really want to know?"