Maybe the natural sources and sinks really do dominate the 400 ppm global CO2 balance and mankind's 2 ppm «imbalance» is lost even deeper in the data noise of natural variability. (wattsupwiththat.com)
The prevailing view at that time, to which I subscribed, was that the signal of human - induced global warming first clearly emerged from the background noise of natural variability starting in the 1970s and that the observed rate of increase from 1975 onward could be expected to continue into the 21st century. (dotearth.blogs.nytimes.com)
«As a result, the signal is very strong so we can more easily detect it amongst noise of natural variability compared to other types of extreme events.» (wxshift.com)