From the devastating fire The polar bear’s grip on ice melts, there’s no shortage of gruesome images to highlight the need for action. Climate change. But collecting reliable data to track the rate of change – and helping to determine how to deal with it – is much less straightforward.
These scientists National Physical Laboratory Teddington in south-west London is using precision monitoring equipment to measure pollutants and track our effects on the planet more accurately than ever before.
The lab’s latest tool is the Borias, a laser spectrometer designed to collect and analyze methane — a greenhouse gas emitted by the activity of dozens of people, from agriculture to fuel. Heathfield, Surrey, Borias operates an uninterrupted telecommunications tower 24 hours a day, in all weathers, to sample large quantities of air. The machine uses a lengthy tube filled with fine plastic beads, which is then cooled to -160 degrees Celsius, allowing researchers returning to NPL headquarters to cryogenically separate methane particles from oxygen and nitrogen, which turn into ice at much lower temperatures.
The purpose is to determine the relative density of different methane molecules and to gain a better idea of where the pollutants are coming from, explains Emmal Safi, a senior research scientist at NPL. “Although previous devices have been able to measure methane concentration, that data alone does not tell us much about the source of methane,” he says.
Methane is a molecule made up of one carbon atom surrounded by four hydrogen atoms (its chemical formula is CH4). However, there are different types of methane in the air, which is called methane isotope. “Different processes produce methane with very small differences in the relative amounts of each isotope, so the relative proportions of each can be used as a signature to determine its origin,” Safi said.
So far, the readings show researchers what they expected: “We’re seeing methane with a signature background in the Northern Hemisphere – relatively clean air from the Atlantic – and some local agricultural sources,” said Chris Renick, a research scientist from a more advanced Boryas team. “It depends on the direction of the wind on any given day.”
What makes Borias unique is its potential: in the future, NPL will create more devices like this and deploy them to different regions, including the Arctic, where potentially huge amounts of methane can be trapped in permafrost. “We are using data from our Heathfield Labs to contribute to the UK’s methane emissions estimates,” Renick explained. “However, there are many more networks in many other countries that would also benefit from the measurements that Boris could make – this would help the device reduce global methane emissions.”
Borias is one of dozens of unique tools for measuring contaminants in the NPL. The most historically significant is a set of high-precision scales developed in the 1970s to compare cable balances, electrical and mechanical power. Fifty years later, the device was used to weigh individual air particles to determine the concentration of methane.
The main role of researchers working with boriasis is not to conduct climate research, nor to present evidence of climate change. They are metrologists by trade – there to study and observe the science of measurement to keep science as accurate as possible.