One North American leader attending the summit in Johannesburg — Canadian Prime Minister Jean Chretien — took significant steps toward establishing his green legacy at home yesterday by unveiling a major expansion of the national parks system and promising to ratify the Kyoto Protocol by the end of the year. His plan to create 10 new parks and five marine conservation areas drew near-universal praise, but the oil-rich province of Alberta remained a vocal opponent to any effort to bring Canada onboard with Kyoto. Chretien said the majority of Canadians wanted to fight global warming, and he cited a current drought in Alberta as evidence that no Canadian province can afford to drag its feet on the issue. But Alberta has threatened to go to the nation’s top court to stop the treaty from being implemented.