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Nature has a news feature on efforts to predict the climate over the short term (5-10 years). Well worth a read.

Climate change: The forecast for 2018 is cloudy with record heat
In August 2007, Doug Smith took the biggest gamble of his career. After more than ten years of work with fellow modellers at the Met Office's Hadley Centre in Exeter, UK, Smith published a detailed prediction of how the climate would change over the better part of a decade1. His team forecasted that global warming would stall briefly and then pick up speed, sending the planet into record-breaking territory within a few years. The Hadley prediction has not fared particularly well. Six years on, global temperatures have yet to shoot up as it projected. Despite this underwhelming result, such near-term forecasts have caught on among many climate modellers....

In preparation for the IPCC report, the first part of which is due out in September, some 16 teams ran an intensive series of decadal forecasting experiments with climate models. Over the past two years, a number of papers based on these exercises have been published, and they generally predict less warming than standard models over the near term....“Although I have nothing against this endeavour as a research opportunity, the papers so far have mostly served as a 'disproof of concept',” says Gavin Schmidt....

Smith and his team....collected a slew of climate measurements — air temperature, wind speed and direction, atmospheric pressure, ocean temperature and salinity — for 20 days during 2005. For each prediction, they 'initialized' the Hadley Centre's main climate model by plugging in a single day's data....The results looked promising at first. The model initially predicted temperatures that were cooler than those seen in conventional climate projections — a forecast that basically held true into 2008. But then the prediction's accuracy faded sharply: the dramatic warming expected after 2008 has yet to arrive. “It's fair to say that the real world warmed even less than our forecast suggested,” Smith says. “We don't really understand at the moment why that is.”....

“We do see that there are some improvements,” says Lisa Goddard, a climate scientist at Columbia University in New York who is heading a systematic analysis and comparison of the predictions from the IPCC models5. Many models, for instance, captured a sudden warming of sea surface temperatures in the North Atlantic that began around 1995. “They all predict the shift beautifully,” Goddard says. “Unfortunately, from what I hear, different models are doing it for different reasons.”

If so, the models' success could be deceptive: whatever accuracy they show for the first year or two of their predictions might stem in part from the fact that the simulations start off with a snapshot of the current climate. Because the climate does not usually change drastically from one year to the next, the model is bound to start off predicting conditions that are close to reality. But that effect quickly wears off as the real climate evolves. If this is the source of the models' accuracy, that advantage fades quickly after a few years....

Smith...has set up a 'decadal exchange' to collect, analyse and publish annual forecasts. Nine groups used the latest climate models to produce ten-year forecasts beginning in 2011. An analysis of the ensemble6 shows much the same pattern as Smith's 2007 prediction: temperatures start out cool and then rise sharply....“I wouldn't be keen to bet on that at the moment,” Smith says, “but I do think we're going to make some good progress within a few years.”

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