Examining this coral record has shown that ENSO has indeed operated over the past 130,000 years, even during the very cold glacial times, although its intensity has varied. The team found that during the twentieth century ENSO was strong compared with previous cool glacial times. Part of the continuing uncertainty is not knowing what the comparison would be with times that are as warm as global climate change forecasts would suggest are on the way. The Earth is heading towards temperatures warmer than experienced for millions of years, so there is no way of examining what ENSO has done in the past under these conditions. It is predicted that global temperatures will rise on average by between 1 and 3 degrees as the greenhouse effect takes effect.
Much more research is needed to come to such a conclusion.
Dr Tudhope envisages taking a closer look at those warmer periods of the Holocene and last interglacial as his next likely research direction. In addition, he plans to work closely with climate modellers to see what effect these new data have on computer models and where the knowledge gaps still remain.