Researchers from the US and the UK have found that the Earth's oceans are becoming greener and that this is due to the impact of climate change on phytoplankton populations as the world warms. The study, which analysed two decades of satellite imagery, found that more than 56 percent of the world's oceans have changed colour from blue to green. Tiny microbes, including plant-like algae, use green chlorophyll to photosynthesise. So the more of them there are, the greener their habitat becomes.