The United Nations Environment Program (UNEP) on Friday said annual climate change adaptation cost in developing countries is likely to reach two to three times the previous estimates of 70-100 billion U.S. dollars per year by 2050, despite the cut of global greenhouse gas emissions.

Commenting on UNEP's Adaptation Gap Report released during the 20th Climate Change Conference (COP20) held in Lima, UNEP's Executive Director Achim Steiner said world delegates gathering in Lima should urgently include integral adaptation plans in the COP20 agreements.

"As world leaders meet in Lima to take the critical next step in realizing a global agreement on climate change, this report underlines the importance of including comprehensive adaptation plans in the agreement," said Steiner.

Released during a crucial round of climate talks in Lima, the report serves as a preliminary assessment of global adaptation gaps in finance, technology and knowledge, and lays out a framework for future work to overcome these gaps in the future, said Steiner.

Steiner added that without further action on cutting greenhouse gas emissions, as UNEP's Emission Gap Report 2014 outlined, the cost of adaptation will soar even further as wider and more-expensive action will be needed to protect communities from the intensifying impacts of climate change such as droughts, floods and rising sea levels.

The Adaptation Gap Report "provides a powerful reminder that the potential cost of inaction carries a real price tag. Debating the economics of our responses to climate change must become more honest. We owe it to ourselves but also to the next generation, as it is they who will have to foot the bill," Steiner noted.