Marine ecosystem
An estimated 1 million common murres died in 2015 and 2016. Scientists fear it was a harbinger of a warming world.
The planet’s largest carbon sink is a major focus at the United Nations climate summit in Madrid, Spain.
Scientist compares spiking temperatures to devastating wildfires in the sea.
The changes in hue will be hard to spot, but they make a big difference in marine ecosystems, scientists report.
