The role of non-governmental organizations (NGOs) in climate policy and the green transition (conservation of biodiversity, energy transition, climate change) is becoming increasingly important worldwide. This paper examines the contribution of NGOs to drafting and implementing climate policy in Tunisia, engaging in climate negotiation processes and activities, and formulating effectiveness criteria related to climate change lobbying at the local, national, and international levels. First, we show that improved working conditions have a positive effect on NGO involvement in climate change actions. Second, greater professionalism has a substantial effect on Elaboration Resilience 2050, Elaboration of a Low Carbon Economy 2050, and climate change training, whereas the effect of the Conferences of the Parties (COPs) is marginally negatively significant. Third, exclusion from the drafting of government laws is a major determinant of involvement in climate change actions. Fourth, NGOs which cooperate with the government and receive funds from international organizations are more likely to be involved in climate change actions, climate policy, climate negotiations, and NGO projects. Fifth, NGOs working on project implementation do not have sufficient resources to undertake several activities simultaneously. Sixth, budget increases and the number of funding sources seem to be positively correlated to engagement in policy changes/negotiations and the implementation of climate projects.