Plans to control climate change by generating white clouds above the oceans could be counter-productive, scientists have discovered. Advocates of geoengineering had suggested that injecting sea spray into the atmosphere could form clouds that would reflect more sunlight than usual due to their salt content. But researchers from the University of Leeds and the Finnish Meteorological Institute found that the technique could interfere with natural cloud formation in some areas. "At best it would have only a tiny effect. Generating a uniform covering of reflective clouds would be extremely challenging," said Ken Carslaw, a professor in Leeds' School of Earth and Environment.