Atmospheric molecules collide with each other which may initiate chemical reactions to occur. In that case the reactant molecule, e.g., volatile organic compound, converts to the product molecule, e.g., low-volatile organic molecule. This kind of product is ‘‘sticky,’’ meaning that when it collides with another molecule, they may stick to each other, and the aerosol particle formation process begins. Aerosol particles impact to the Earth’s surface temperature by directly scattering the sunlight and indirectly acting as cloud condensation nuclei. In Molecular Level Atmospheric Science group, computational and spectroscopic methods are used to find how molecular properties affect to the aerosol particle formation. This ‘‘molecules to climate’’ integration is crucial for predicting impacts of aerosol particles on both air quality and climate change, which will aid to make environmentally sustainable political decisions.