Gerard Early was responsible for developing and implementing the laws when they were first created, before becoming head of the federal environment department.

He is now director of BirdLife Australia and is arguing against the Morrison government's plans to devolve commonwealth environmental approvals to the states.

The Abbott government tried to make similar changes in 2014.

Mr Early told a Senate inquiry the changes risk taking the laws back to times when there was community unrest over environment issues and conflicts between levels of government.

"History suggests to me that this bill would have perverse outcomes that would fly directly in the face of those who are supporting it," he said on Monday.

"If this bill were made into law it would increase risk and uncertainty, not reduce it.

"The Australian community expects the Commonwealth to have a leadership role in biodiversity conservation and environmental protection, independent of particular state and territory interests."

The Australia Institute presented research to the inquiry showing 0.8 per cent of projects were rejected by the Environment Protection and Biodiversity Conservation Act.

Mr Early acknowledged the data didn't take into account proposals changed through the approval process, but agreed only a sliver are knocked back.

"The argument that the EPBC Act is creating havoc for industry and stopping things is just absolute rubbish," he said.

The step comes from Professor Samuel's interim review of the laws, but the government has rejected his key recommendation of establishing an independent environment watchdog.

Prof Samuel's interim report said Australia's natural environment was under increasing threat and declining at an unsustainable pace.

Under the shift in approvals, states would have to follow national environmental standards, but the standards have not yet been developed by the federal government.

The government has received Prof Samuel's final report, and environment groups are urging for it to be released before any changes to the law are made.

Monday's inquiry heard from multiple environment groups concerned about the changes and their impact on conservation.

Australian Conservation Foundation chief Kelly O'Shanassy said national environmental laws were the most important thing to prevent extinctions.

The Senate inquiry plans to report on the changes by Friday, giving committee members less than two weeks to comb through submissions.

More than 40 submissions have been published, with the overwhelming majority rejecting the proposal.

The Property Council, Australian Petroleum Production and Exploration Association and the Minerals Council of Australia are among a handful that support the changes.

They don't believe changing the environmental approvals process will have any impact on the environment.

Australian Associated Press