The nature of the trend in global and hemispheric temperatures

The aim of this note is to provide evidence about the existence or non-existence of a stochastic trend in the global temperatures time series by using standard unit root tests. Three sets of data are considered in this paper: global, Northern Hemisphere and Southern Hemisphere monthly temperature anomalies. Our main finding is that there is not a stochastic trend in the temperatures time series and they are stationary around a deterministic trend.