Nationwide Monitoring Network to Monitor Global-Warming Gases

[Bob Simmons]

The monitoring network which is expected to grow initially focus on pinpointing the sources and concentrations of methane, potent contributor to climate change. The California plan is early example of the kind of system that may be needed in many places as countries develop plans to limit their emissions of greenhouse gases.

While monitoring stations around the globe already detect carbon dioxide, methane and other greenhouse gases, they are deliberately placed in remote locations and are generally intended to measure global concentrations of greenhouse gases rather than local emissions.

The California network, by contrast, is meant to help the sate find specific sources of emissions, as well as to verify the state's overall compliance with a plan it adopted to limit greenhouse gases.

The air resources board has bought seven portable analyzers made by Picarro, a company in Silicon Valley that also supplies the machines to the federal government and academic scientists.

By the summer, the analyzers will be deployed on towers in the San Joaquin and Sacramento Valley, home to large agricultural operations and old fields, and on Mount Wilson, outside Los Angels. Data will also be collected from Picarro machines maintained by the Lawrence Berkeley National Laboratory on the Coast and from several monitoring stations operated by other agencies.

Depending on local topography and weather conditions, one Picarro analyzer can cover as much as several hundreds miles, the scientist said. For instance, a machine installed on a mountain peak can collect data from most of the Los Angels basin.

The state's global warming law requires that greenhouse gas emission be cut to 1990 levels by 2020. To achieve such reductions, the state is planning an emission-trading market whose integrity will depend on accurate measurement of the gases from oil refineries, power plants and other industrial facilities.

Pieter Tans, a senior scientist in Colorado with the National Oceanic and Atmospheric Administration said "I think these monitoring networks are going to be essential, as we really need to have a system in place that makes sure markets match reality"

The air resources board uses computer modeling to estimate greenhouse gas emissions in the state. The first task of the new network will be to see if actual concentrations of methane match those estimates.

A Picarro analyzer costs $50,000. It is about the size of a desktop PC and takes precise, real-time measurements of greenhouse gases. Picarro’s chief executive, Michael Woelk, said his company’s scientists had charted plumes of methane by placing an analyzer in a car and driving from Livermore, Calif., to Sacramento, a route heavy with animal feedlots, truck depots and other industrial operations.

This is the first critical step to building a nationwide monitoring network, "Mr. Woelk said.

Source: "NY Times"