Carbon dioxide (CO2) garners the lion’s share of attention when it comes to humanity’s greenhouse gas (GHG) emissions, and rightly so. The concentration of CO2 in the atmosphere has increased about 35 percent since the beginning of the Industrial Age, to about 390 parts per million by volume. At around 27 billion metric tons per year, man-made, or anthropogenic, CO2 emissions are some 130 times greater than than that emitted by volcanoes, the largest natural source.
The rising levels of CO2 we’re pumping into the atmosphere aren’t our only concern, however. Along with CO2, man-made emissions of methane (CH4), nitrous oxides (NOx) and hydrofluorocarbons (HFCs) have been rising rapidly since the dawn of the Industrial Age.
Devising and enacting climate change and clean energy policies and action plans to reduce GHG emissions calls for an improved capacity to measure GHGs. Companies such as Picarro are stepping into the breach, so to speak. The Santa Clara, California-based developer and manufacturer of a new, vastly improved and far less costly generation of chemical isotope analysis equipment on April 10 announced that it’s expanded its product line with with the introduction of “a new, high precision analyzer, model G5101-i, for measuring nitrous oxide (N2O) concentrations and isotopomers in air.”
NOx, Greenhouse Gases and the Greenhouse Effect
“A molecule of hydrogen, for example, whether in Sirius or in Arcturus, executes its vibrations in precisely the same time. Each molecule therefore throughout the universe bares impressed upon it the stamp of a metric system as distinctly as does the metre of the Archives at Paris, or the royal cubit of the Temple of Karnac.”
- James Clerk Maxwell, Lecture to the British Association at Bradford (1873), ‘Atoms and Molecules’. Quoted by Ernest Rutherford, in ‘The Constitution of Matter and the Evolution of the Elements’, The Popular Science Monthly (Aug 1915), 112.
Methane and nitrous oxide are far more potent greenhouse gases than CO2: methane’s got a 20-year Global Warming Potential (GWP) 72-times that of CO2. Nitrous oxide’s 20-year GWP is 289-times that of carbon dioxide. Man-made emissions of both CH4 and NOx are far smaller, however.
In terms of net radiative forcing — the atmospheric warming capacity of a greenhouse gas — NOx ranks third behind CO2 and CH4, according to the International Panel of Climate Change’s (IPCC) climate science standards. Water vapor is actually the greatest contributor to the greenhouse effect, accounting for 36-72 percent, with CO2 ranking second between 9-26 percent. Methane ranks third, accounting for 4-9 percent of the global greenhouse effect.
New Insights Spanning Agriculture, Ecosystems and Climate Change
N20 is of increasing interest to scientists and policy makers due to its linkage across agriculture, industry, natural ecosystems and climate. “As the world’s population grows, understanding nitrogen cycles will become increasingly important in managing land, water, and fertilizer usage and combating global warming,” according to Picarro. “Since 1750, atmospheric N2O levels have risen 20 percent, from below 270 parts per billion (ppb) to more than 320 ppb.”
Picarro’s G5101-i N2O analyzer provides a means of measuring N2O concentrations in the atmosphere much more easily, with far greater precision and at a far lower cost than has been the case, the company says. The G5101-i enables users to “fingerprint” N2O sources and distinguish between the nitrogen oxide isotopomers N-14/N-15/O-16 and N-15/N-14/O-16 at a precision better than 0.5 per mil.
A rising world population is placing greater strains on humanity’s agricultural capacity and the earth’s natural resources. “Scientists have now determined through isotopic data that the increase in N2O in the atmosphere is directly linked to the increase in fertilizer use,” Picarro points out.
“N2O, which is emitted throughout the nitrogen cycle, has 298-times the global warming potential of carbon dioxide (CO2) over a one hundred year period. In addition to its impact on the climate, N2O also destroys stratospheric ozone, which protects the planet from harmful ultraviolet rays.”
Picarro’s G5101-i affords scientists the ability “to make more stable and precise measurements continuously from the air or from small-volume samples, such as those collected from soil or water extractions,” the company explains, enabling them “to gather real-time data while in the field or the lab.”
“Many of our customers have been eagerly awaiting the release of the G5101-i because it is vital in supporting their research on a number of critical projects,” said Michael Woelk, Picarro’s CEO. “Developing a stable, high performance mid-IR (infrared) platform has been both fascinating and challenging for our research and engineering teams because of the complexity of the science involved and because we have very high standards. I’m proud of our team and believe customers will be proud to own this instrument.”
With the launch of its N20 analyzer, Picarro is now manufacturing environmental isotope analysis equipment spanning carbon dioxide, methane, water vapor and nitrous oxide– the four most critical greenhouse gases.