Carbon Pulse: The US and Canada on Thursday announced a joint effort to curb methane emissions from their oil and gas sectors, and said they would expand their collaboration on carbon markets by working together to ensure the environmental integrity of new emissions units. US President Barack Obama and Canadian Prime Minister Justin Trudeau said their countries would aim to cut methane from oil and gas by 40-45% below 2012 levels by 2025, with Canada effectively signing up to targets previously announced by the...