Mexico, Canada and the United States have agreed to work together to protect the monarch butterfly, threatened in Mexico by illegal logging destroying its winter nesting grounds.

Meeting in the central Mexican state Michoacan, where millions of butterflies spend the winter months, the three-country Commission for Environmental Co-operation, or CEC, formally pledged Wednesday to support conservation initiatives for the monarch, a commission statement said.

The monarch butterfly is not listed as endangered but scientists said deforestation could threaten its existence.

The monarchs' annual 5,500-kilometre journey from the forests of Canada and parts of the U.S. to the central Mexican mountains is considered an aesthetic and scientific wonder.

While there was talk of co-operating to save species and fight pollution, there was also concern that the commission was more concerned about politics than the environment.

Ann Mitchell, a Canadian delegate from the Canadian Institute for Environmental Law and Policy, complained that even when the CEC produces excellent research, political ministers often do nothing to implement recommended changes.

"We have a problem in terms of … the political will to take action to remedy it," she told the CBC.

Contributed to carbon emissions 

And though the air was thick with talk of global warming and greenhouse gases, the conference was full of participants whose flights to Mexico contributed tonnes of carbon emissions to the environment.

Quebec delegate Jean Guy Depot said that as an environmentalist, it would be his last time travelling by air for the CEC.

"In the future I won't take planes outside of Canada so it's probably my last visit to Mexico. And I would like to participate by webcam," he said.

Exequiel Escurra, a leading research scientist from Mexico, said he hoped the commission would address controversial trade-related issues such as U.S. corn subsidies.

He said the subsidies are devastating to Mexican farmers, who are driven off the land and forced to clearcut forests in order to grow more corn. The crisis is both a social and an environmental one, he said.

Efforts to save vaquita marina

"There's an issue of justice in the subsidies that I do hope the Commission for Environmental Co-operation can see because it is related to trade, which is the basic role for the CEC," he said.

Along with efforts to save threatened monarch butterflies, the three countries also agreed to joint efforts to aid the vaquita marina, a grey porpoise native to the Gulf of California, also known as the Sea of Cortés or the Sea of Cortez. They are sometimes caught in fishing nets and their habitat is damaged by shrimp boats that trawl the sea floor.

Only 500 of the porpoises are thought to exist, environmentalists say.

The CEC — a panel set up by Mexico, the U.S. and Canada under the North American Free Trade Agreement — also said it has launched a Google Earth mapping tool that lets users explore pollution data from more than 30,000 industrial facilities in the three countries.

With files from the Associated Press