Global Warming An Univariate Estimation of Sea Temperature Data

Type/nr R11/06
Skrevet av Torbjørn Lorentzen
The report deals with detecting climate change in the sea waters off Norway. According to the UN Intergovernmental Panel on Climate Change, IPCC, the climate on earth is changing. The main cause is the combustion of fossil fuel and the emission of greenhouse gases with accompanying higher temperature in the atmosphere. Higher temperature is expected to change ecosystems, and in turn influence industries based on natural resources, for example traditional fisheries and aquaculture. This report analyses whether there has been a change in the temperature in the coastal waters off Norway, and whether a signal of global warming can be detected. The statistical analysis uses sea temperature time series data from coastal near area off Lista in the south and Skrova in the north of Norway. The analysis shows that the time series are principally stationary with oscillatory traits. The main conclusion is that the applied statistical estimators cannot detect any climate change during the time period 1936-2003 – except for the August temperature off Lista which indicates nonstationarity. On the other hand, if sub-samples are selected, it is more likely to detect changes. The temperature has increased during the period 1980-2003 especially off Lista, but the detected increase could be a part of a natural cycle.
Språk Skrevet på engelsk