Long-term observations records are needed to separate the anthropogenic causes and natural variability of climate change impacts. With satellite observational data now available for more than 30 years, and other field-based observations, it should be possible to attribute changes across regions to anthropogenic forcing.
Alemu Gonsamo from University of Toronto, Canada and co-workers use satellite and field observations of the Northern Hemisphere to investigate a number of indicators across land, cryosphere and ocean. Climate indicator datasets such as snow cover, sea ice extent and concentration, sea level rise, spring thaw and onset of growing season are considered, in combination with atmospheric CO2. The data span three decades from 1980–2012, although individual datasets vary in length and start date.
There is a long-term relationship observed between temperature and several indicators. Detrending the data shows that natural forcers, such as solar radiation and teleconnections, are the main driver of interannual variability. In contrast, atmospheric CO2 concentration displays a strong relationship with small interannual variability. The authors show coherent change across different biological and physical systems, which is not related to natural variability but can be attributed to anthropogenic forcing.
About this article
Cite this article
Wake, B. Coherent change across systems. Nature Clim Change 6, 895 (2016). https://doi.org/10.1038/nclimate3131