Nature has published the first article to "formally link observed global changes in physical and biological systems to human-induced climate change, predominantly from increasing greenhouse gases." See news story here and the article, "Attributing physical and biological impacts to anthropogenic climate change" (subs. req'd, abstract below).
NASA's discussion of the piece here explains, "human-caused climate change has made an impact on a wide range of Earth's natural systems, including permafrost thawing, plants blooming earlier across Europe, and lakes declining in productivity in Africa." The image at right: "Impacts from warming are evident in satellite images showing that lakes in Siberia disappearing as the permafrost thaws and lake water drains deeper into the ground." The lead author explained: