When it comes to greenhouse gas emissions, the proposed Mackenzie Valley gas pipeline would be like adding 400,000 more cars to the roads of the Northwest Territories, Ecology North spokesman Doug Ritchie says.

Speaking to the Mackenzie Gas Project Joint Review Panel in Yellowknife Wednesday, Ritchie said the increased emissions generated by the multibillion-dollar project would simply add to the growing problem of climate change.

The federal government wants pipeline proponent Imperial Oil and its partners to minimize emissions but it has not set any specific targets.

Ritchie says Imperial Oil should have to offset the damage of additional emissions by building 8,000 wind generators and renovating six million homes.

Imperial Oil's Michelle LaPlante says the project would add 1.7 million tonnes to the territory's annual emissions, effectively doubling the current amount, which is low compared with other jurisdictions.

However, she said, expecting the pipeline owners to pay for alternatives such as wind generators is unrealistic.

"Implementing Ecology North's recommendation would impose a significant cost burden which goes well above and beyond any requirement for any project in Canada," LaPlante said. 

Environment Canada representatives told the panel they did not think the project would "degrade air quality significantly" in the region.