Reuters: Shipping is slowing climate change by spewing out sunlight-dimming pollution but a clean-up needed to safeguard human health will stoke global warming, experts said Friday. “So far shipping has caused a cooling effect that has slowed down global warming,” Jan Fuglestvedt, of the Center for International Climate and Environmental Research Oslo (CICERO), told Reuters. “After some decades the net climate effect of shipping will shift from cooling to warming” because of cleaner …