columns, both extremely weak. In 2005 a 30% reduction in the warm currents that carry water north from the Gulf Stream was observed from the last such measurement in 1992. The authors noted uncertainties in the measurements. Following media discussions, Detlef Quadfasel pointed out that the uncertainty of the estimates of Bryden et al. is high, but says other factors and observations do support their results, and implications based on palaeoclimate records show drops of air temperature up to 10 °C within decades, linked to abrupt switches of ocean circulation when a certain threshold is reached. He concluded that further observations and modelling are crucial for providing early warning of a possible devastating breakdown of the circulation. In response Quirin Schiermeier concluded that natural variation was the culprit for the observations but highlighted possible implications. In 2008, Vage et al. reported "the return of deep convection to the subpolar gyre in both the Labrador and Irminger seas in the winter of 2007–2008," employing "profiling float data from the Argo program to document deep mixing," and "a variety of in situ, satellite and reanalysis data" to set the context for the phenomenon. This might have a lot to do with the observations of variations in cold water chimney behaviour. Projections The research around the future strength of the AMOC is shown below in chronological order. It is primarily based on Atmosphere-Ocean General Circulation Models projections, although large reviews like the IPCC reports are also informed by the present-day observations and historical reconstructions, which allows them to take a wider range of possibilities into account and assign likelihood to the events not explicitly covered by the models. Around 2001, the IPCC Third Assessment Report projected high confidence that the THC would tend to weaken rather than stop, and that the warming effects would outweigh the cooling, even over Europe. When the IPCC Fifth Assessment Report was published in 2014, a rapid transition of the AMOC was considered very unlikely, and this assessment was offered at a high confidence level. That assessment had several limitations, such a reported bias of CMIP models towards AMOC stability, and the insufficient analysis of the impacts on circulation caused by Greenland Ice Sheet meltwater intrusion. In 2016, a study aimed to redress this shortcoming by adding Greenland ice sheet melt estimates to the projections from eight state-of-the-art climate models. It found that by 2090–2100, the AMOC would