Science Alert  December 4, 2018 The project – called the Stratospheric Controlled Perturbation Experiment (SCoPEx) – is part of Harvard’s Solar Geoengineering Research Program. To cool down the surface of the planet, in the experiment Harvard University researchers will fly a high-altitude balloon up to the stratosphere, at an altitude of about 20 kilometres, and release a small aerosol plume of calcium carbonate that is expected to disperse into a perturbed air mass about 1 kilometre long and 100 metres in diameter. The balloon will then fly back and forth through this cloud repeatedly for about 24 hours, analysing the […]