During her tenure, she was elected three times as the Chairperson of the Special Permanent Parliamentary Committee on Environmental Protection and the Subcommittee of the Water Resources.

[1] During her tenure, Dionysia-Theodora focused on the financing of sustainable development; the efficient waste management and the development of a circular economy; the empowerment of the enforcement mechanisms of Environmental Law; the support of innovative technologies, including space technologies, for the protection of the natural environment; the promotion of renewable energy sources; the mitigation and adaptation of climate change and the support of technologies of CO2 capture, storage, conversion and reuse; the nexus between environment, agriculture, and food; the nexus between environment and public health, and the sound management of water resources.

Avgerinopoulou also serves as a Member of the Audit and Finance Subcommittee of the GWPO, while her vision within the Organization is the promotion and realization of Sustainable Development Goals[4] No 6 and 14.

In 2014, she was elected as the Chairperson of the United Nations Affairs Committee of the Inter-Parliamentary Union (IPU), due to her extensive knowledge of the UN System, acquired throughout her doctoral studies and her previous parliamentary and professional engagements.

[5] She has also previously worked as an advisor at the European Union Delegation to the United Nations in New York, dealing mainly with the environment and sustainable development agendas.

Leading a dynamic network of Parliamentarians, members of the Environment Committees of twenty-six countries around the Mediterranean Sea, Avgerinopoulou put a special emphasis on efforts for the de-pollution of the Mediterranean, the combat against marine litter, and especially micro-plastics; she actively participated in dialogues for the destruction of the chemical weapons of Syria, while she tackled issues of climate change adaptation, with an emphasis on the vulnerable coastal and forest areas.

As the Deputy Head, she substantially contributed to the strategic planning of the Party regarding environmental policies by following a large-scale systems and holistic approach.

She also served as the Deputy Secretary of Volunteerism and NGOs, where she worked closely with civil society representatives on a country level in various initiatives.

Avgerinopoulou has devoted an important part of her pro bono work to humanitarian and environmental goals, including the prevention of anthropogenic and natural disasters, the post-disaster management, and relief and reconstruction efforts.

Avgerinopoulou has also been active in a series in relief and reconstruction efforts after the occurrence of disasters worldwide, such as after the earthquake in, the wildfires in Haifa, Israel, and the nuclear accident in Fukushima, Japan.