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Before starting One Blue Marble, I spent considerable time visiting political web sites to better understand why conservatives think that global warming is a huge hoax perpetrated by scientists (read: socialists) who are hellbent on destroying our cherished way of life.

But I came away empty. There was nothing there, no insight to be gleaned. Instead I found only ideologues distorting science for their own tragic end. They perpetuate myths that have no basis in fact, myths that have been discredited again and again. I would feel sorry for them if the stakes weren’t so high.

The Truth About Climate Models

Among the most persistent false beliefs is the claim that we shouldn’t move to a renewable, clean energy economy because all the climate change warnings are derived from computer simulations, and models are a very poor branch of science that is easily manipulated to prove anything you want.

Like all denier arguments, this is one hell of a whopper, but you’ll see it repeated ad nauseum throughout the blogosphere. Like most climate change myths, it uses sophistry and cheap tricks to hide a hidden political agenda. Irrelevant points are polished and prettied to masquerade as reasonable facts, but don’t be fooled. It’s all just a con game to keep naive readers from doing their homework.

On astroturfing sites, the conventional wisdom suggests that:

  1. Computer models are unproven, so we shouldn’t put our faith in them
  2. The climate system is incredibly complex, and no computer model can possibly do justice to these complexities.
  3. Clouds are incredibly important, yet none of the climate models accurately predicts how they will influence climate
  4. Scientists can’t predict the weather next week, why should we believe what they say will happen in 25 years?*

I could go on, but you get the point. The essential scam here is that if they throw enough confusion into the air, they can divert you from this essential truth.

Climate models are inaccurate, and they are also incredibly useful.

Sid Crosby, the Stanley Cup, and Global Warming

Let me explain it this way. The Stanley Cup playoffs are currently dominating the sports news in Canada. Lets say that I created a serious computer model to predict the winner. Which would be harder to do… Write a program that accurately predicted the every single detail of every single game played during the 2009 playoffs, or write a program that just predicts who wins each series and, ultimately, Lord Stanley’s Cup.

Climate change deniers argue that the only correct way for me to proceed would be to write a program that predicts every niggling detail accurately, from the number of minutes played by Penguins’ superstar Sidney Crosby to the number of saves made by Vancouver’s Roberto Luongo. The deniers argue that if I can’t predict Crosby’s playing time, then my model is a incomplete and utter waste of time.

More Astroturfing

That’s what astroturfing — a targeting misinformation campaign — is all about. Keeping the analogy, the deniers and astroturfers are hoping that you’ll take your eye off the puck, because they don’t want you to know that my computer program has accurately picked the Stanley Cup winner for the last 20 years.

And so it goes with climate models. If you used the best system current available to predict the 24-hour temperature in Halifax, Nova Scotia on May 1, 2012, then a climate model will prove woefully inadequate. But if you use a climate model to predict warming trends due to rising CO2 emissions between 1990 and 2005, then climate models are frighteningly accurate, and that accuracy is supported by thousands of real world experiments offering hard, empirical data. The science is rock solid.

You see, climate models have been around for more than 20 years, and they’ve already made predictions that have been proven many times in the real world by leading scientists. Climate models have predicted that the Arctic will warm faster than the continental United States, and Arctic sea ice is disappearing at an alarming rate. Climate models suggested that Australia would be hit hard by climate change, and guess what? The country has been suffering from a decade-long drought and devastating crop losses.

Climate Model Successes

Grist offers a few additional climate model predictions that have already come to pass:

  1. models predict that surface warming should be accompanied by cooling of the stratosphere, and this has indeed been observed;
  2. models have long predicted warming of the lower, mid, and upper troposphere, even while satellite readings seemed to disagree — but it turns out the satellite analysis was full of errors and on correction, this warming has been observed;
  3. models predict warming of ocean surface waters, as is now observed;
  4. models predict an energy imbalance between incoming sunlight and outgoing infrared radiation, which has been detected;
  5. models predict sharp and short-lived cooling of a few tenths of a degree in the event of large volcanic eruptions, and Mount Pinatubo confirmed this;
  6. models predict an amplification of warming trends in the Arctic region, and this is indeed happening;
  7. climate models predict continuing and accelerating warming of the planet’s surface, and so far they are spot on.

The Climate Change Smoking Gun

Additionally, we have a very simple way of testing models for accuracy: We can simulations to see how well they can predict the temperatures that have been observed for the last 130 or so years. And when you do that, you get a devastatingly accurate graph like this one:


As John Holdren, Obama’s National Science Adviser suggests, this is the smoking gun. You can argue that this historical accuracy offers no proof that models will accurately predict the future, and you might be right. But all the scientific evidence suggests otherwise, and you’d be asking us to bet the future of humanity on a 250-1 long shot.

A Dystopian Future… Unless

So what are computer models predicting for the next 90 years? Well dear reader, it ain’t pretty. The coming decade will be the warmest ever, and the arctic will largely melt by 2020. Droughts will intensify, and hurricanes will become ever more potent. By 2100, we expect that sea levels will rise by between 5 and 7 feet, that 85 percent of the Amazon rainforest will die, that 50 to 70 percent of species will go extinct, that agriculture will fail in California, that the American Southwest will be turned into a permanent dust bowl, and that a few billion people in Asia to have no water to live on. And that’s but a sampling of dozens of apocalyptic predictions.

We need to find a new way of living, one that treads lightly on the planet and powers our society with clean, renewable energy. It doesn’t need to be an empty life without meaning. For the west, it will be a test, but one that we can meet. For the developing world, it’s a matter of life and death. I believe that we must not fail them.

Support Waxman-Markey

Right now, if you’re American, the most important thing you can do is to support American Clean Energy and Security Act by writing your state’s representatives in the House. And if you are Canadian, you can work to unseat the federal Conservativess who are bringing us to financial and environmental ruin.

Our window of opportunity is small, and the challenge is great. There is no time to lose.


*Climate and weather are two different things, and deniers often mistake the two.

2 Responses to “Climate Models: The Unvarnished Truth”

  1. Peter Sinclair says:

    can you help me with the source to the “smoking gun” graph?

  2. Richard says:

    Hi Peter:

    I grabbed a screen shot from John Holdren’s talk about global warming last year… At The American Response to Climate Change conference.