The report, Biodiversity Offsetting, by the Environmental Audit Committee, says that the government’s plans to introduce a system of biodiversity offsetting for new building developments could enhance the way the planning system accounts for the damage done to natural habitats, but the proposals must be improved to offer adequate protection for wildlife habitats.
The report says that a mandatory, rather than voluntary, offsetting system "would encourage a market to develop, which would in turn allow more environmentally and economically viable offset projects to be brought forward".
The report concludes that poor uptake in the pilots "suggests that a mandatory system is needed, but that the case for that has not yet been made and more analysis of the pilots is needed".
The report warns of a danger that an offsetting market could produce many offsets "of a similar, lowest-cost, type rather than a mixed range of habitats".
It recommends that the government task Natural England with monitoring any offsetting scheme introduced "to ensure a balance of habitat types are covered in the offsets, so that overall they are broadly similar to the habitats that are lost".
Offsets would also have to be near enough to the development site that local people can still enjoy the types of habitat and wildlife being affected, the MPs argue.
Elswhere, the report says that the government’s green paper on the issue does not provide an evidence based analysis of how offsetting would deliver "biodiversity gain". It says a 20 minute assessment for calculating biodiversity losses at a site, that has been proposed by ministers, is "overly simplistic".
The report recommends that this should include particular species, local habitat significance, ecosystem services provided – such as pollination and flood prevention - and ‘ecosystem network' connectivity to reflect the full complexity of habitats.
The document says that offsetting pilots, set up in 2011, should be allowed to run their course and then be subjected to an independent evaluation. It says that if that evaluation concludes that there are benefits in introducing an offsetting scheme, the government should then bring forward revised proposals that reflect the concerns raised in the report.
Joan Walley MP, chair of the Environmental Audit Committee said: "Ministers must take great care to get offsetting right or they risk giving developers carte blanche to concrete over important habitats."
"Many witnesses to the inquiry were concerned that the government's proposal would allow offsetting to be applied to ancient woodland and Sites of Special Scientific Interest. There is a danger that an overly simplistic offsetting system would not protect these long-established eco-systems."
The government set out its proposals for biodiversity offsetting in a consultation, Biodiversity Offsetting in England, published in September 2013.
Biodiversity Offsetting can be read here.