Guest Post: Atmospheric surface warming stalled by strong Trade winds driving heat into Pacific ocean

By Michael Hopkin, The Conversation, who interviewed Steve Rintoul from CSIRO, Richard Allan Professor of Climate Science at University of Reading, and Mathew England a Climatologist at University of New South Wales.

The “pause” in global warming since 2001 can be explained by the discovery of unusually strong winds in the Pacific, climatologists have found.

Global surface air temperatures have more or less flatlined since the turn of the century, prompting some observers to claim that the planetary warming trend has stopped. But the new research, published in Nature Climate Change, shows how stronger winds have driven the excess heat down into the ocean.

Researchers led by Matthew England, a professor of climatology at the University of New South Wales, began by looking at the differences between the 1990s, when Earth’s surface was strongly warming, and the 2000s, after the hiatus began.

Previous research has already shown that cooler temperatures over the eastern Pacific are linked to a slowdown in worldwide warming, but researchers wanted to know why.

Exclimate: Are recent global temperatures predicted by climate models?

This article is a little bit of a tangent to my regular articles. I am presently doing an online course - Climate Change: Challenges and solutions - offered by the University of Exeter (UK). So please indulge me as I also use this blog for some climate course work. This article is for week 3, section 4.4 of the course on 'IPCC Fifth Assessment Report'.

The IPCC recently published their Fifth Assessment Report (2013). Does the recent change in global temperatures reflect the predictions of climate models? Search for other feedback in the media and focus on the role of climate models and then try to address the discussion question: Does the recent change in global temperatures reflect the predictions of climate models?

An interesting question, because recent global mean surface temperatures over the last 15 years from 1998 show only a very slight warming trend. In the HadCRUT4 temperature data series the trend is 0.04°C per decade over 1998–2012, compared to 0.11°C per decade over 1951–2012. This is used by climate sceptics to argue that 'global warming has stopped'.

So have climate models predicted this slow down in temperatures?

Not per se. But global climate models do include natural variability cycles as part of their long term average trend. In some periods of a similar length of time warming is greater than the average, and in some it is less or even shows a measure of cooling. This can be seen even in the last 100 years. So, yes, this recent slow down in global temperatures over the last 15 years forms part of long term climate model trends.