 The Tropospheric Temperature Controversy. Climate model simulations indicate that rising greenhouse gas concentrations will induce warming not only at earth’s surface but also in the layer of atmosphere extending 8–12 km above the surface, known as the troposphere. Satellites and radiosondes are the primary means of monitoring temperatures in this layer. Analyses of these data in the early 1990s, when only about a decade of satellite data was available, indicated a lack of warming in the troposphere (Spencer &amp; Christy 1990). Prima facie, this presented a challenge to climate science, and it became a key piece of evidence in contrarian dismissals of the threat of anthropogenic climate change. Over time, additional research uncovered numerous problems with the satellite and radiosonde data used to estimate tropospheric temperature trends, with many of these problems related to homogenization (NRC 2000; Karl et al. 2006). More recent observational estimates agree that the troposphere has been warming and, although observed trends still tend to be somewhat smaller than those in simulations, the mainstream view is that there is “no fundamental discrepancy” between observations and models, given the significant uncertainties involved (Thorne et al. 2011). Nevertheless, the debate continues (see, e.g., Christy et al. 2010; Santer et al. 2017). Lloyd (2012) suggests that this controversy in part involves a conflict between a “direct empiricist” view that sees observational data as a naked reflection of reality, taking priority over models, and a more nuanced “complex empiricist” view (see also Edwards 2010: 417).