We present the development of the adjoint of a comprehensive cloud droplet formation parameterization for use in aerosol-cloud-climate interaction studies. The adjoint efficiently and accurately calculates the sensitivity of cloud droplet number concentration (CDNC) to all parameterization inputs (e. g. https://www.markbroyard.com/top-super-pet-naturals-busy-butter-calming-peanut-butter-for-cheap-limited-save/