Canada’s already-tense internal battle over whether to ratify the Kyoto Treaty on climate change heated up further yesterday, when the province of Alberta withdrew from negotiations after its alternative emissions-cutting plan was rejected by the other provinces and territories. In response, Alberta resigned as co-chair of the commission formed to negotiate climate issues and refused to sign the communique issued by the nation’s other energy and environment ministers. Without Alberta in the picture, it will be difficult for Canada to comply with the Kyoto accord, because the province produces about a third of the nation’s greenhouse gas emissions. The stage is now set for even more internal friction: The federal government has said it is prepared to override Alberta’s opposition if necessary, and there are rumblings that the province could go to court to avoid complying with the treaty if it is ratified.