Nature Geoscience
Nature Geoscience 5,86–89(2012) doi:10.1038/ngeo1390 Timothy M. Lenton, Michael Crouch,Martin Johnson, Nuno Pires & Liam Dolan
View Journal Article / Working PaperThe Late Ordovician period, ending 444 million years ago, was marked by the onset of glaciations. The expansion of non-vascular land plants accelerated chemical weathering and may have drawn down enough atmospheric carbon dioxide to trigger the growth of ice sheets.