HARRISBURG (AP) — Josh Shapiro, the Democratic candidate for governor, is breaking with Gov. Tom Wolf on the centerpiece of Wolf’s plan to fight climate change amid the pushback it has received from influential building trades unions. Wolf has worked for two years to impose a price on carbon dioxide emissions from fossil fuel-fired power plants. But Shapiro is suggesting that Wolf’s plan does not satisfy criticism that it will hurt the state’s power industry, drive up electric prices and do little to curtail greenhouse gases. Shapiro’s statement came as he prepared Wednesday to address union leaders from the pipeline trades who planned to question him about his position.