Ascension Island is in the middle of the AtlanticSidney Sambu/Getty By Adam VaughanThe world’s ability to track rapidly growing levels of greenhouse gases has suffered a major blow with the axing of a vital climate monitoring scheme run from a UK-governed island. For 40 years US and UK teams have been monitoring concentrations of carbon dioxide and methane on Ascension Island, a volcanic rock in the middle of the Atlantic. The air sampling station is the only one in the Atlantic and one of just a handful in the tropics, providing crucial data about how oceans are absorbing carbon dioxide and the atmosphere’s response to our burning of fossil fuels. But the operation has been downsized and will soon end entirely, raising concerns in the scientific community over the hole left in their ability to track humanity’s impact on the climate. Advertisement The UK’s Met Office, which runs the programme in partnership with US agency National Oceanic and Atmospheric Administration (NOAA) and Royal Holloway, University of London, has halved the number of staff it sends to the island from four to two, as a result of damage to the island’s only runway limited most flights. Climate cutbacks That left the job of collecting air samples a voluntary one that relies on goodwill. New Scientist has learnt that in late April the Met Office took the decision that it could no longer assist NOAA by providing the samples. Ed Dlugokencky of NOAA says: “Ascension was NOAA’s only air sampling site providing background composition of air entering the South American continent. Without it, our ability to estimate natural greenhouse gas fluxes for the Amazon and other South American ecosystems will be diminished.” A key piece of equipment is also no longer working. A machine for measuring the composition of the air, which was installed in 2010 and billed as “vital” and “major UK contribution to global understanding of the greenhouse gases”, has not been calibrated for two years and is now offline. “Trying to model global greenhouse gas budgets without Ascension measurement is like trying to ride the Grand National on a horse with three legs,” says Nisbet. The Met Office says it will still support Royal Holloway in the monthly job of collecting flasks of air from the island and flying them to the UK. But even that monitoring will soon end too, as it emerged this week that the UK research council that pays for the work has decided it will no longer fund the project beyond April 2020. Read more: Earth’s methane emissions are rising and we don’t know why Dlugokencky says Ascension’s location and long historical record mean it is vital to keep monitoring going. “Long measurement series are useful for looking at subtle changes possibly caused by a changing climate,” he says. The imminent end of monitoring on Ascension come as NOAA data released on Tuesday revealed levels of CO2 in the atmosphere last year jumped by the second highest annual increase. They follow a recent surge in methane emissions, which researchers are still unable to fully explain but monitoring stations such as Ascension are considered key to understanding where the methane is coming from. Dlugokencky says it is becoming increasingly difficult to maintain the global air sampling network. “Some cooperating agencies who originally contacted us two or three decades ago to join our network are now less keen to work with us or are asking for financial support to keep sampling,” he says. The Met Office says the primary task of staff on the island is to assist the UK Ministry of Defence (MOD) there. “With a smaller team, we have had to critically review all of the non-MOD work we carry out and unfortunately, we are no longer able to assist NOAA with their air sampling on the island due to the task complexities and level of training involved,” says Vicky Smiley of the Met Office. More on these topics: climate change