It was a dark day for environmental science and policy in Canada on 29 June.

The country's Conservative Party has been steadily dismantling environmental protection since winning a majority government last year (see, for example, Nature http://doi.org/h2v; 2012). Further alarming changes to environmental laws were concealed in a 'budget bill' that was ratified by the Senate on 29 June.

For example, the Canadian Environmental Assessment Act has been replaced by a weaker law that reduces government oversight of the environmental impact of a proposed pipeline from the Alberta oil sands to tankers off British Columbia. Canada's Fisheries Act now allows for more pollution and no longer protects fish habitats, except for fisheries. The National Round Table on the Environment and the Economy, which provides independent scientific advice on sustainable development, will be dissolved in March 2013. A finance committee that had no scientific or public input has decided that this massive legislative overhaul could proceed as written.

Globally significant research facilities have already been axed, including the renowned Experimental Lakes Area and the Polar Environment Atmospheric Research Laboratory in the high Arctic. Scientific agencies such as Fisheries and Oceans Canada (DFO), Environment Canada and Parks Canada have had to sack most of the personnel responsible for habitat management and monitoring, including those in the DFO's marine-pollution programme.

The new legislative framework marginalizes science in environmental management, and could do irreparable harm to the environment and the economy it supports. Such tactics match Canada's intransigence on climate change: the same bill made it the first country to pull out of the Kyoto agreement.