What effect — if any — such an impact may have had on this period of global environmental change 55 to 56 million years ago remains unclear. (aaas.org)
An enhanced greenhouse effect is believed to be responsible for global environmental change and global warming. (hubpages.com)
But we're trying to make predictions about what's going to happen under global environmental change and use that as a basis for protection and developing a sustainable future. (discovermagazine.com)