Is Science Infallible?
A recent editorial in a local newspaper contained the following statements with regard to the proposition that humans are the driving force behind global warming -- the theory of anthropogenic global warming, or AGW:
a. A scientific consensus cannot be wrong.
b. The scientific consensus is that humans are causing global warming.
c. Therefore, humans are causing global warming.
For the purpose of this argument, I'll give the writer a pass on "b" for now. But what about that first assumption? Can the scientific consensus be wrong? If so, under what conditions?
A Brief History of Astronomy
A long time ago in a kingdom far away, people used to watch the night sky and wonder what it all meant. Some began keeping records of the motions of shiny things in the sky. It became obvious that everything rotates about the earth. Were they wrong? Yes, they were. Why were they wrong? Were they stupid? No, they weren't stupid. They were dealing with limited data, and converged on the simplest theory that agreed with the known data. Ockham would have been proud.
Ptolemy to the Rescue
Then it was noticed that some of the shiny objects didn't behave quite the same way as the rest. Sometimes they went faster, sometimes they went slower. It was decided that these were planets rather than stars. But the paths of the planets' motion threw a monkey wrench into the simple geocentric system with circular orbits. Ptolemy's response to the new data was to propose a system in which the circular orbits of the planets included little loops call epicycles. Eventually, the Ptolomaic system became the order of the day. Was it right? Again, no.
Why did he get it wrong? Once again, he came up with the simplest theory based on known data. He did the right thing, but got the wrong answer.
Was he stupid? I hardly think so. The geometric calculations required to arrive at the system of circular orbits with epicycles to match the observed data are beyond the ability of most people living today.
Part of the reason he got it wrong may have been the political influence of the "Church". It was politically incorrect to even think that the earth was not the center of the universe. And they took their political correctness very seriously back then. It was a matter of life and death.
Copernicus Saves the Day
About 1500 years later, along came Copernicus. He successfully promoted the revolutionary idea that the earth was not the center of things, but the sun. But guess what? He -- and the new scientific consensus he helped create -- got it wrong. Again! His system put the sun at the center, but retained the circular orbits with circular epicycles.
Was he stupid? No, he wasn't. He did the best he could with what was known then, and provided a theory that was a better match for ever-improving data. It also defied the scientific consensus of the day. It took great courage, intelligence, persistence, and hard work. But it was still wrong.
Galileo was a supporter of the Copernican system. Was he stupid? No, he clearly was not. He was an expert in mathematics, kinematics, and astronomy. He was more right than the previous consensus, yet he still got it wrong. Doh!
Oopsie! Keppler Saves the Day
Then came Keppler. He spent a lot of time and energy defending the Copernican system against the lingering geocentric consensus. Working with the ever-more-precise observations of Tycho Brahe, he eventually changed the orbits of the planets from circles to ellipses and eliminated the epicycles. Finally, someone got it right!
So What?
It is apparent that the scientific consensus can be wrong. What are the causes of an incorrect consensus?
First, let's reject outright the notion that the originators of wrong ideas might have been stupid. Ptolemy, Copernicus, and Galileo were not stupid. Here are some ideas that can be gleaned from the history of astronomy:
1. Insufficient data -- you do the best you can with what you've got. If you don't have much data or the "right" data, you will most likely come to the wrong conclusion.
2. Political influence -- when the powers-that-be say that the correct conclusion is "A", it is difficult to buck the trend and say "B".
3. Inertia -- the longer and more widely an incorrect idea is accepted, the more difficult it is to overturn.
Could AGW (gasp) Be Wrong?!?
Is it possible that the consensus that humans are causing global warming might be wrong? Let's see:
1. Insufficient data:
It is also informative to follow the money. There can be found all sorts of nasty business conspiring to perpetuate the idea of AGW, things like carbon traders, lawyers, and the disposition of research dollars. It's ironic that AGW skeptics are often accused of being corrupted by money from "big oil."
Enough Already -- Wrap It Up!
The bottom line is that a scientific consensus can be wrong, and the theory of anthropogenic global warming exhibits the characteristics of of an incorrect consensus. That doesn't prove the theory's wrong, but it does suggest that we shouldn't be taking drastic action just because there's a consensus.
It also suggests that a discussion of the science is always appropriate, even if there is a consensus.
- "...the science on global warming is beyond debatable, it's irrefutable..."
- "To claim that it's still debatable is tantamount to doubting the hazards of smoking."
a. A scientific consensus cannot be wrong.
b. The scientific consensus is that humans are causing global warming.
c. Therefore, humans are causing global warming.
For the purpose of this argument, I'll give the writer a pass on "b" for now. But what about that first assumption? Can the scientific consensus be wrong? If so, under what conditions?
A Brief History of Astronomy
A long time ago in a kingdom far away, people used to watch the night sky and wonder what it all meant. Some began keeping records of the motions of shiny things in the sky. It became obvious that everything rotates about the earth. Were they wrong? Yes, they were. Why were they wrong? Were they stupid? No, they weren't stupid. They were dealing with limited data, and converged on the simplest theory that agreed with the known data. Ockham would have been proud.
Ptolemy to the Rescue
Then it was noticed that some of the shiny objects didn't behave quite the same way as the rest. Sometimes they went faster, sometimes they went slower. It was decided that these were planets rather than stars. But the paths of the planets' motion threw a monkey wrench into the simple geocentric system with circular orbits. Ptolemy's response to the new data was to propose a system in which the circular orbits of the planets included little loops call epicycles. Eventually, the Ptolomaic system became the order of the day. Was it right? Again, no.
Why did he get it wrong? Once again, he came up with the simplest theory based on known data. He did the right thing, but got the wrong answer.
Was he stupid? I hardly think so. The geometric calculations required to arrive at the system of circular orbits with epicycles to match the observed data are beyond the ability of most people living today.
Part of the reason he got it wrong may have been the political influence of the "Church". It was politically incorrect to even think that the earth was not the center of the universe. And they took their political correctness very seriously back then. It was a matter of life and death.
Copernicus Saves the Day
About 1500 years later, along came Copernicus. He successfully promoted the revolutionary idea that the earth was not the center of things, but the sun. But guess what? He -- and the new scientific consensus he helped create -- got it wrong. Again! His system put the sun at the center, but retained the circular orbits with circular epicycles.
Was he stupid? No, he wasn't. He did the best he could with what was known then, and provided a theory that was a better match for ever-improving data. It also defied the scientific consensus of the day. It took great courage, intelligence, persistence, and hard work. But it was still wrong.
Galileo was a supporter of the Copernican system. Was he stupid? No, he clearly was not. He was an expert in mathematics, kinematics, and astronomy. He was more right than the previous consensus, yet he still got it wrong. Doh!
Oopsie! Keppler Saves the Day
Then came Keppler. He spent a lot of time and energy defending the Copernican system against the lingering geocentric consensus. Working with the ever-more-precise observations of Tycho Brahe, he eventually changed the orbits of the planets from circles to ellipses and eliminated the epicycles. Finally, someone got it right!
So What?
It is apparent that the scientific consensus can be wrong. What are the causes of an incorrect consensus?
First, let's reject outright the notion that the originators of wrong ideas might have been stupid. Ptolemy, Copernicus, and Galileo were not stupid. Here are some ideas that can be gleaned from the history of astronomy:
1. Insufficient data -- you do the best you can with what you've got. If you don't have much data or the "right" data, you will most likely come to the wrong conclusion.
2. Political influence -- when the powers-that-be say that the correct conclusion is "A", it is difficult to buck the trend and say "B".
3. Inertia -- the longer and more widely an incorrect idea is accepted, the more difficult it is to overturn.
Could AGW (gasp) Be Wrong?!?
Is it possible that the consensus that humans are causing global warming might be wrong? Let's see:
1. Insufficient data:
- We're dealing with extremely limited temperature records, to the point that many researchers spend all their time trying to come up with temperature proxies -- like tree rings and ice cores -- that can be used to fill in the gap from the beginning of the planet to, oh, about 100 years ago. Pretty big gap.
- The earth's climate system is so complex that it will be a long time before we really understand it well. Everything affects everything else. Anyone care to write the equation for that?
- Because the data is so scarce, ridiculously complex and arcane statistical methods are employed in an attempt to pull "signal" out of the noise. Are the methods valid? Who knows?
- One word: algore.
- Another word: Hollywood.
- The news media would not publish a story about how the earth's climate is robust and stable. That's boring. But give them catastrophe and alarmism and you will be famous!
- Another word: lawyers
- Political opportunity -- why else would the UN care?
- Propose a research project to the National Science Foundation that might suggest that humans are not the cause of global warming. Will you get the grant? Sorry. It might be interesting, but since it doesn't agree with the consensus it would be a waste of money.
- Write a paper exploring the correlation between variations in solar irradiation and climate change on earth and other planets. Will it get published? Sorry again. Why publish something that is obviously misguided, even if no factual, logical or statistical errors can be found?
- Suggest in any public forum that perhaps the idea of anthropogenic global warming needs a little more work. Sorry. You will be shouted down with, "There's a consensus, stupid!"
It is also informative to follow the money. There can be found all sorts of nasty business conspiring to perpetuate the idea of AGW, things like carbon traders, lawyers, and the disposition of research dollars. It's ironic that AGW skeptics are often accused of being corrupted by money from "big oil."
Enough Already -- Wrap It Up!
The bottom line is that a scientific consensus can be wrong, and the theory of anthropogenic global warming exhibits the characteristics of of an incorrect consensus. That doesn't prove the theory's wrong, but it does suggest that we shouldn't be taking drastic action just because there's a consensus.
It also suggests that a discussion of the science is always appropriate, even if there is a consensus.
posted by Pops | 5:32 AM
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