Climate change sceptics out in the cold

Human activities are causing ocean temperatures to rise, according to a paper published in the American journal Science on 3 June, 2005.

Tim Barnett, the lead author on the paper said: ‘The evidence, based on computer models and observations in the field, is so strong that it should put an end to any debate about whether humanity is causing global warming.’

In the paper the scientists describe how they have been able to rule out natural climate variability and solar or volcanic forcing as explanations for the observed warming in the oceans over the last 40 years. The observed temperature rise in the oceans is only accurately simulated by climate models if greenhouse gas emissions from industry, agriculture and transport are incorporated.

Jonathan Gregory, from the Centre for Global Atmospheric Modelling at the University of Reading, worked on the interpretation of the data: ‘This research complements that done on atmospheric temperature change. Analysis of the ocean component of climate models agrees with conclusions about the atmospheric surface temperature simulated by models: that human influence is causing the warming we are measuring.’

Jonathan, funded by the Natural Environment Research Council and the Hadley Centre for Climate Prediction and Research added: ‘The pattern is also consistent with several other earlier studies showing that ocean temperatures will rise with increasing levels of carbon dioxide in the atmosphere.’

The research found that in all of the ocean basins, the warming in the upper 700 metres in the models corresponded to the measurements obtained at sea with confidence exceeding 95 percent. The correspondence was especially strong in the upper 500m of the water column. It is this high degree of agreement and statistical significance that leads the team to conclude that the warming is the product of human influence.

Tim, a marine physicist from Scripps Institution of Oceanography, San Diego, said: ‘The argument that climate models are so inaccurate as to be unbelievable is no longer tenable. They do the temperature part of the problem correctly and that suggests their forecasts for the next couple of decades are apt to be reasonably correct. This means the reality of global warming is likely to be underscored by changes that millions of people will feel in their lives.’