"The only source of knowledge is experience." - Albert Einstein What is the project? Make Sunsets wants to make it easy to cool the planet to solve climate change. Right now, that means they send balloons into the atmosphere filled with Sulfuric Dioxide in order to cool the planet and prevent climate change.
Here are 20 reasons why releasing 'clouds', i.e. air pollutants like sulfuric dioxide, may be a bad idea: https://climate.envsci.rutgers.edu/pdf/20Reasons.pdf