Associated Press: The 2,700 pigs on the farm that John Horrevorts manages yield more than ham and bacon. A biogas plant makes enough electricity from their waste to run the farm and feeds extra wattage into the Dutch national grid. He even gets bonus payments for reducing greenhouse gas emissions. As the world struggles to reduce pollution causing climate change, attention has focused on the burning of fossil fuels in factories, power stations, and vehicles. But U.N. scientists says farming and …