The Climate Institute will close on June 30 after failing to secure enough funding to continue operations.

The Sydney-based independent policy think tank was established in 2005, and at the time was the only non-government organisation focused solely on climate change.

Board Chairman Mark Wootton says the institute has been a leading advocate for “credible, practical climate policy” during a tumultuous period.

“It has conducted ground-breaking research, built strategic partnerships, influenced public policy, changed the regulatory landscape and driven the evolution of financial sector climate risk management.”

“We are proud of the way [the council] has built understanding and consensus among a wide variety of stakeholders on such a complex, challenging and important issue,” he said.

“We are disappointed that some in government prefer to treat what should be a risk management issue as a proxy for political and ideological battles.

“They are increasingly isolated as the costs of inaction mount and the opportunities and benefits of action become ever clearer.”

The institute’s board contains academics and business people, and was funded by private donors. It has been struggling since last year to source continuing philanthropic support.