The president of Iceland is coming to Maine. Olafur Ragnar Grimsson will be the keynote speaker at Maine International Trade Day on May 31 at the Marriott at Sable Oaks in South Portland. Grimsson will speak about business opportunities that might be created as climate change shrinks the polar ice cap. His visit comes a couple of months after Icelandic shipping company Eimskip made Portland its primary East Coast port of call. Grimsson is expected to discuss how the receding polar ice could open northern shipping routes between North America, Europe, and Asia in the future, while making natural resources such as gas and iron ore more accessible.