how do those climate models work?
Computer modeling used in climate science is an easy target for the global warming deniers. And it is not hard to see why. The actual climate and its interactions with earth and all its various systems is extremely complex. Modeling those relationships in a computer, well, how can that possibly tell us much of anything? Especially when the models that exist often disagree.
That’s a good question. And one that TRC is not qualified to answer. But there are people out there who are qualified, and understanding how the evidence for global climate change comes about is important for those of us who argue that the evidence for global climate change cannot be denied.
And with that goal in mind, TRC recommends an article from Science Line: The future’s not straightforward: neither is modeling it. The piece is a conversation with Anthony Del Genio, from NASA’s Goddard Institute who currently works on the Cassini mission, and presents a clear, comprehensible look at how computer modeling of climate change (on earth and on Venus) works. It’s worth a look.
Although each new model is more sophisticated than the last, their initial results may actually look worse. Newly proposed models don’t usually agree with each other, Del Genio says, because they’re created by different groups of scientists who all have their own ideas on how to accommodate new factors. Climate change denialists use those discrepancies between the present 14 to 18 models to claim that they shouldn’t be trusted at all, but Del Genio — who doesn’t see how anyone can deny the reality of human-induced climate change based on the evidence — stresses that the disagreements over modeling are a natural part of the scientific process.
What we do know, Del Genio says, is that the Earth is warming in response to increases in greenhouse gas emissions. All the models predict higher temperatures in the future, but there is a debate about how much it will warm up and what that warming means.
No matter how sophisticated models get, the predictions will remain uncertain. Predictions always are. “We all envy Ebenezer Scrooge in a way,” Del Genio says. “He had the Ghost of Christmas Yet to Come. We wish we had the Ghost of Climate Yet to Come to show everyone what we think the world is going to be like if we continue along the current path…But we don’t have that.”