Radio frequencies needed for weather forecasts, early warning systems, climate monitoring and water management must be safeguarded against the growing threat of interference from emerging technologies, the United Nations said on Monday.Some sensors measure very weak naturally occurring signals at specific frequencies, making protection from harmful interference particularly important.The systems enable observations of the atmosphere, oceans and land, and the transmission of data that supports life-saving early warnings, reliable weather forecasting and long-term climate monitoring.But the UN telecommunications and weather agencies warned on Monday that increasing use of frequencies by other radio communications services, including wireless and satellite services, was raising the risk of interference affecting the frequency bands required for such systems.They cautioned that radio frequency interference could disrupt measurements, reduce data quality or availability and thereby compromise the reliability of forecasts and alerts, affecting authorities’ ability to prepare for and respond to environmental hazards.Meeting in Geneva this week for an expert seminar, the International Telecommunications Union (ITU) and the World Meteorological Organisation (WMO) are calling on governments and regulatory authorities to protect access to frequencies vital for meteorology.”As we speak, satellites are measuring changes in our oceans and our atmosphere,” ITU head Doreen Bogdan-Martin told Monday’s event.”Radars are tracking storms as they develop,” she explained, including the powerful Nor’easter storm that lashed her home region in the heavily populated US Northeast corridor at the weekend, knocking out power for thousands and killing at least one person.Unique forecasts”Interference-free spectrum keeps weather forecasts accurate, emergency alerts and warnings timely and climate data reliable so communities can prepare, respond and build resilience,” Bogdan-Martin stressed.”Preventing harmful radio interference is a matter of public safety and can save lives.”Weather radar, lightning location systems, aircraft and marine observation, hydrological monitoring and other vital systems all rely on these frequency bands to collect and exchange data.Speaking to Monday’s gathering, WMO chief Celeste Saulo described how the systems worked.”A storm reveals itself in the faint natural signals it emits and in the echoes returned by the signals we send to prove it,” she said.”Essentially, all of this happens because there is a physical relation between the size of a droplet and the size of ice crystals in the clouds and the frequency spectrum,” she pointed out.These frequencies, she said, “enable observations that no other frequencies can provide.””These bands must be protected.”