# Predicting Short-Term Change

*Published:* 2007-08-10
*Author:* Lisa Moore

*The author of today"s post, [Lisa Moore, Ph.D.](http://www.environmentaldefense.org/page.cfm?tagID=404), is a scientist in the Climate and Air Program.*

[Climate models](https://blogs.edf.org/climate411/2007/07/02/climate-models-how-they-work/) are usually run far into the future, projecting temperature changes to the end of the century. Over the long term, the effects of greenhouse gases overwhelm all other factors. But climate can have substantial "short-term internal variability" – for example, temperature shifts due to El Niño and La Niña. Climate models have never been able to predict this internal variability – until now.

A paper in today’s issue of *Science* ("[Improved Surface Temperature Prediction for the Coming Decade from a Global Climate Model](http://www.sciencemag.org/cgi/content/abstract/317/5839/796)") describes a new and improved climate model that predicts both greenhouse warming and internal climate variability. The model’s hindcasts are substantially better than earlier model results. (For more on hindcasts, see the post "[Climate Models: How Good Are They](https://blogs.edf.org/climate411/2007/07/18/models_how_good/)?").

When the authors ran their model into the future, they found that internal variability would offset global warming until 2008, but the new model (like older models) predicts significant warming during the coming decade. At least half the years after 2009 are predicted to exceed the warmest year currently on record.

So while the improved predictability of short-term variability is welcome, the long-term picture remains the same. The world is getting warmer.