"Estimated uncertainty" refers to a calculation or guess of how much doubt or lack of sureness there is in a particular measurement or statement. Full definition
Also some of the available reconstructions estimate the uncertainties in the reconstruction. (realclimate.org)
Combining this with the uncertainties of the proxy data outlined in Fig. 2 we can roughly estimate the uncertainty of our solar forcing value to be 50 %. (aanda.org)
Our experiments suggest that both statistical approaches should yield reliable reconstructions of the true climate history within estimated uncertainties, given estimates of the signal and noise attributes of actual proxy data networks. (mustelid.blogspot.ru)