WASHINGTON (AP) — President Joe Biden plans to mark Earth Day in Seattle on Friday, but he’s struggled to make progress on a sweeping environmental agenda. Some of his plans for fighting climate change remain stalled on Capitol Hill, particularly hundreds of billions of dollars for tax credits to support clean energy. At the same time, scientists have escalated their warnings about the potential effects of global warming. The Democratic president’s deputy national climate adviser says the administration has accomplished a lot and has a long way to go. Biden visits Portland, Oregon, on Thursday on a swing through the Pacific Northwest, a region often on the forefront of environmental efforts.