Sea ice is melting due to global warming, enabling greater maritime access to the Arctic Ocean. Emissions from transoceanic cargo ships taking advantage of this could either warm the climate further by darkening snow and ice surfaces or cool it by enhancing cloud reflectance. In a study published recently in the American Geophysical Union journal Geophysical Research Letters, researchers from UCI, the University of Connecticut and the Pacific Northwest National Laboratory describe using a fully coupled global climate model to simulate – for the first time – the effects of emissions from trans-Arctic shipping.
Results showed that these emissions will increase regional cloudiness in the summer and offset Arctic warming by about 1 degree by 2100. Thicker summertime clouds reflect more solar radiation back into space, reducing energy absorbed by the planet’s surface and cooling ocean temperatures later in the fall. In turn, ice formation is boosted in the following winter, which compounds the cloud-induced cooling.
