Waste management is a critical policy towards the reduction of environmental impacts to air, soil and water. Many Latin American countries, however, lack a correct waste management system in many cities and rural areas, leading to the accumulation of unmanaged waste in illegal or unregulated dumpsites. The case of Peru is of interest, as it hosts 5 of the 50 largest dumpsites in the world. An erratic waste management compromises climate actions for Peru to commit with the Paris Agreement, as no correct closure systems are established for these dumpsites. Therefore, the main objective of this study is to assess the contribution of the past and present biodegradable waste produced and disposed of in the most critical open dumpsters to the overall annual greenhouse gas (GHG) emissions of Peru using the IPCC model. Thereafter, the climate change mitigation potential of possible dumpsite closure strategies based on a selection of technologies, including economic feasibility, were estimated. Results show that cumulative GHG emissions in 2018 for the 24 critical dumpsites evaluated added up to 704 kt CO2 eq. and a cumulative value of 4.4 Mt CO2 eq. in the period 2019–2028, representing over 40 % of solid waste emissions expected by 2030. Mitigation potentials for these emissions tanged from 91 to 970 kt CO2 eq. in the ten-year period depending on the mitigation strategies adopted. The costs of these strategies are also discussed and are expected to be of utility to complement Peru's waste management commitments in the frame of the Paris Agreement.