Saturday, March 29, 2008

The Climate Models Are Wrong

It wasn't so long ago, that there was a quite different campaign warning of the dangers of climate change. In the 1970's, the climate crisis du jour was global cooling. This is because temperatures had been declining for several decades, from the 1940's through the 1970's. It was predicted at the time that we were headed towards a global cooling catastrophe (loss of farmland, severe storms, etc) if the trends were to continue according to the best models science had to offer. The prevailing theory at the time was that aerosols given off by factories, automobiles, deforestation, farming, etc. was reflecting sunlight back into space from the atmosphere, causing cooling throughout the planet.

It turns out those models were wrong. In the 1980's the trend reversed, and we had global warming throughout the 1990's. In particular, 1998 was the warmest year on record. What were climate scientists to do? The new paradigm was that the cooling effect of aerosols was counteracted by the effect of greenhouse gases, particularly carbon dioxide, which has been increasing consistently since the Industrial Revolution. So the new mantra has become that our consumption of fossil fuels is gumming up the global climate system, causing it to warm up like a car with its windows up on a hot summer day. When reconstructing temperatures from the past and projecting them into the future, we had the hockey stick model, where due to accelerating carbon dioxide levels, we would have accelerating temperatures, until the planet turned into a smoldering cauldron, much like Venus.

However, it just so happens that if you take the hot, steamy year of 1998 as a reference point, we've had global cooling1:

World Temperatures according to the Hadley Center for Climate Prediction. Note the steep drop over the last year.

Which Leads us to Dr. Miklós Zágoni, a climate specialist who worked for NASA. Since the climate predictions of massive global warming turned out to be wrong as of late, he tasked himself to refine the climate models. It turned out that the carbon dioxide model for global warming made a flawed assumption in its equation. Namely, to simplify one of the thermodynamics equations, an assumption was made that the atmosphere has infinite height. Since I have an engineering degree, it's not unusual to see equations simplified using assumptions--with the understanding that the results would be identical when the assumptions are made. In this case though, Dr. Zágoni discovered that accelerating heating would not happen, that there would be a ceiling to the amount of global warming due to carbon dioxide. This sounds like good news! We won't all die, and we won't need complex and onerous carbon legislation! Dr. Zágoni's reward? He was summarily defrocked and excommunicated by NASA.

Is this really about science, or is it as much about orthodoxy, bureaucratic inertia, and grant money? Perhaps if we have problems predicting weather into the news ten days, maybe we should be wary of making temperature predictions for the next 100 years.

Update 2008/3/31: I think the best model that explains global warming (as opposed to the prevailing anthropogenic CO2-based theory of global warming) is the one which ties global temperatures directly to solar activity. The increased presence of CO2 in the atmosphere would be explained mostly that it would be released from the oceans as they warmed; as opposed to being a cause of the warming they would be a symptom.

1 It was actually a challenge to find temperature data for the past 10 years. A little too convenient, if you ask me.


Anonymous said...

blog posts based on the 20 year chart crack me up because they originally accompanied a 100-year chart. but that one doesn't tell the story you're looking for. you'll conclude with the century ahead, while skipping the one behind us. intellectually what?

Unknown said...

If you had read my post (instead of knee-jerking), you'd realize that said there was global cooling when taking 1998 as a reference point. If you take 1908 as a reference point, then yes, we've had global warming. The point is that the prediction that global warming would accelerate from 1998 onward is false.

Planetary climate is a cyclical thing, dependent more on the oceans, plate tectonics, than anything else. There's abolutely no way to know whether the next hundred years will be hotter or warmer. And if it gets a little hotter, chances are it won't be a big deal, and it will come so slowly, that there will be ample time to adapt. I will cover all these points in future posts.

1000 years ago, wine grapes grew in Northern Britain. 400 years ago the Thames would freeze over to the point of having winter fairs on the river. Humans managed just fine in both situations. Climate change shouldn't be feared at all.

Unknown said...

Whoops, that should have read oceans, plate tectonics, and the sun.

Anonymous said...

Tell that to the Bangladeshis who are being flooded or those who are findingless and less space to grow crops...

Surely when debating human impact on climate change we should be looking at graphs which start at the beginning of the industrial period. Whenwe do that there has in fact been a dramatic increase in global warming. Hence the international concern that wehave something to do with it... I agree that there is natural climate change but the debate is that we have played a major part in causing the current acceleration.