Science Buddies: "Ask an Expert"

Hi - found your site by chance - searched for 'ask an expert' and your site came up near the top the list - and it looks really good.

I have a question about science itself - while doing some reading on climate change I have come across a claim by some skeptics of human caused climate change that there is no empirical evidence to support climate change, and since - they claim - Science is "decided by Empirical evidence only", then the climate science is not scientifically correct, logically speaking.

I'm doing my own assessment of the studies and evidence for and against - I think there is human induced global warming, but I want to see for myself so I'm looking into it.

But the statement that "Science is decided by empirical evidence only" is what I would like some help with, if possible.

I have found that this is not completely true as formal sciences like mathematics or information science do not rely on empirical evidence and I've learned a bit about the distinction between a priori knowledge or 'before the fact' knowledge (as in maths) and post priori knowledge (as in empirical science areas - natural and social), but there seems to be some issues here:

1) if global warming hasn't really happened yet - say its only just starting and still within a margin for error of observation - how can there be strong empirical evidence?

2) climate science relies a lot on computer modelling results - opponents of climate science are critical of the validity of this modelling - but is computer modelling sort of halfway between a priori and post priori types of knowledge? or is it a weaker type of a priori knowledge... I'm not too sure on this area.

Each of these points seems to mean it's not logically right to refute climate science for lack of empirical evidence (putting aside whether there is or isn't strong empirical evidence for the moment).

Is the issue somehow related to time? a formal science has theories you can test by experiment- but the passing of time does not change the outcome. A natural science - like geology - you can't experiment but you can look back in time to find evidence to test a hypothesis - with social science you can do experiments but not on the future - you might do experiments following a group of people over time and see what that says...

In climate science it seems as though you can't do experiments, you can't look back in time for evidence and you can't develop rules/theories that wont change over time as the system is too complex and is going to change over time - and you have to rely on computer simulations which are approximations.

Is this a reason that some people - a minority, but quite vocal - are skeptical about climate change?

That might be too big or vague a question... maybe it's a long winded way of saying "it's hard to predict the future"... and humans as a whole have never had to do this before... so this is new territory... anyway I hope you can give me some pointers here

thanks, Chookie

Hello Chookie,

I have read your post with a great deal of interest. You have done a lot of research and I would like to congratulate you for your efforts. You have some very good points about Global Warming.

Unfortunately I cannot really answer your question because at this point nobody really knows for sure what the outcome of all of this will be. As far as Empirical Proof we really do not have any. This is something that has never happened in recorded history.

An example might be that a lot of countries have legends of a time when the earth was covered with water, but nobody can empirically prove that this happened while mankind was here (where did they live during this time?). There is no other evidence than in ancient stories of this occurring. We have some proof that the world was covered with water at one point, but there is disagreement as to exactly when this occurred. Seas fossils may be found on the tops of mountains, but this is not necessarily evidence. The earth's crust is constantly shifting. Most mountains were formed when two tectonic plates met and one plate was shifted up. So one person could say that the fossils were deposited when the land that became the mountain was underwater, while another person could claim that the fossils were deposited on top of the mountains after they were formed. Places with this sort of geological activity are hard to date since it is difficult to prove which thing occurred first. So there is no empirical evidence that either side is right, since both sides views can be challenged.

So what can we prove as far as global warming? The sea has risen a couple of centimeters. Will the rising of the sea continue at this rate, accelerate, or even stop? We just don't know for sure.

I think most scientists have accepted that global warming is occurring and intensifying. Glaciers around the world are melting. The icing of the Arctic and Antarctic Oceans has decreased to the point where some cruise ships are now taking tourists into areas that were never accessible before. Birds and plants that have never previously been able to survive are appearing farther North every year. This is proof of what is happening currently, but some people say that the changes will stop or even reverse by themselves. This seems unlikely to happen, but we have no way of proving that their views are unjustified. Personally I would not buy beach front property at the moment as a long term investment.

Even the scientists that believe that global warming is happening differ on what the outcome will be. Some people think that if we can stop the pollution now, we can reverse the global warming. Some people argue that it is too late and that the process is already irreversible. Even this we do not know. it is unlikely that governments will react and stop pollution enough to prove or disprove the latter point.

As to the skeptics, there will always be skeptics in science. This is actually a good thing. A lot of theories in science have been accepted by the majority of the scientists. At one point the scientists all said that the Sun revolved around the earth. This was the belief for a long period of time as it was supported by the Catholic Church. A small group of scientists believed that it was the other way around from their own observations. Eventually their point was accepted. That is the point of proof in science. You create a theory based on the best evidence available at the time when you are forming the theory. If someone can disprove this theory then people will accept the next theory formed. That is the way science advances instead of staying in one place.

So you are following the path of good science. You have made the Chookie Theory of Global Warming based on what you have found to be evidence to support your final view. There are a lot of people that have formed similar theories based on the same evidence. You followed the facts to reach a logical decision. I applaud your initiative in looking for facts instead of blindly following what other people are saying. Please always retain some skepticism of what people tell you. Keep looking at the facts as the evidence grows, but be open to any evidence for the other side. If you walk the exact same path every day then you might miss what is on the other side of the hill.

I apologize for running on but it is a large question and is something that will effect your future. Hopefully I have helped you a little instead of making everything more confusing. Humans are indeed the great variable in so many things.

Preston

Thank you Preston, that reply did help.

Your point that it's great to question theories but you should do it in an open minded and science based way is good and I will remember it as I work out my question.

On your comment that it's unlikely that governments will react and stop pollution enough - Since we elect governments, then I think it's really up to us. We elected the government, so We are responsible.

I'm sure if many individuals think something needs to Change, and those individuals do Something, Change will happen surprisingly quickly. I think Change is happening now but it's not obvious - a bit like Global Warming.

thanks Chookie

Hi chookie,

Preston had a great response, and I wanted to comment on one point of your original post - "In climate science it seems as though you can't do experiments, you can't look back in time for evidence" (emphasis added). We only have "modern" temperature recordings for the last hundred years or so, when weather stations started using thermometers to record data every day. However, similar to geology, climate scientists actually can look back in time for evidence of what the Earth's temperature was thousands or millions of years ago, what types of gases were in the atmosphere, etc. The first example that comes to mind is ice core data:

https://www.google.com/search?q=ice+cor ... 8&oe=utf-8

This gives scientists a huge amount of data that they can analyze, and that data helps them develop the computer models you mentioned. Preston is right that there are different computer models and they are not all in exact agreement. You will learn as you take more science classes (I'm not sure what grade you're in), that there are mathematical models and equations for all sorts of things in science that help us "predict the future." For example, in a high-school physics class questions like "I throw a ball at a 45 degree angle at a speed of 4 meters per second, where will the ball be 3 seconds later?" are a pretty standard homework problem. Physicists have had the equations that describe the motion of the ball figured out for a while, and relatively speaking, mathematically they aren't that complicated, so there isn't really any "disagreement." Similarly, in the branch of science called thermodynamics (the study of heat, temperature, and energy), there are equations that describe how things heat up and cool down. We have those equations pretty well figured out for reasonably-sized objects like a house, and you could use them to answer a question like "It is 80 degrees in my house and I just turned the air conditioning on. How long will it take before the internal temperature reaches 70 degrees?" The equations that describe climate change on a global scale for the entire planet are much more complicated and have a lot more variables - things like ocean currents, winds, how much of the sun's light is reflected back into space, how much fossil fuels humanity is burning, etc. So, scientists have not fully "figured out the equations" yet; and we don't have a single answer to "we know the temperature and sea level today, what will the exact temperature and sea level be 100 years from now?" Depending on what assumptions you make and what equations you use, the computer models will give different results.

Like Preston said, it is great that you are looking into this yourself, looking for evidence and forming your own opinions. History is full of examples of "accepted" scientific theories that turned out to be wrong (here's an interesting list: http://blog.chron.com/sciguy/2010/11/th ... -theories/), but it also has examples of very vocal minorities that did their best to deny scientific results, to the detriment of public health or the environment (tobacco companies denying that smoking causes cancer comes to mind, or the current anti-vaccine movement).

I thank you for your kind reply Chookie. I tried to compress a lot into a small place, but I am afraid I tend to run on some times. I also appreciate the response from bfinio and the valuable additions. As we all know this problem is much more involved than the few words that we are writing here, but it is good to see people discussing the subject.

I am glad to see that you are more optimistic in the fact that the governments will do something about the pollution problem in time. I am afraid I am old and tend to be more cynical than you. Please do not allow that to affect your opinions. An open mind is a much superior one. I really should have noted that it is doubtful that all of the involved governments will react to reduce emissions immediately. The individual people of a country may be able to effect what their governments do, but people in some of the involved countries do not have much say as to what their governments do.

Please do whatever you can to get other people that you know to work on getting their individual governments to start on the project of reducing pollution. You are correct when you say that a few individuals can affect more and more people. Many people may think that something needs to be done about this problem, but see nothing they can do themselves. If those people gather together and work on the change then more people will see hope to do this and join in.

The future world is the world that you will have to live in so you should have the power to make a difference in the damage that is currently occurring to it. I would encourage you to consider joining one of the many groups that are trying to fight this. You can talk to your friends about doing something to help even if it is picking up trash off the roads. There are groups that will give you equipment to monitor what is happening to the water in your local streams, rivers, and lakes. You can start websites about the problem. Some newspapers would allow you to write a small weekly story about what you have found in the state of the local water and wildlife. If you could start with your friends and demonstrate to people that they can actually make a difference then you can make more people actively work on the problem. The secret is to do something that can demonstrate to people that the problem is real and that they can do something about it.

You are right when you say that the change is already starting to happen, but it is moving very slowly. It needs people like you to speed it up. I do not think that we are at the point where we cannot at least stop the warming from getting worse, but it takes people like you to do this.

So I thank you Chookie for pointing out that I was being cynical about this problem. We all need to be reminded of this from time to time. You are an intelligent and articulate person and you make me feel much better about the future of our planet. I have enjoyed having this conversation with you and would enjoy any future correspondence from you.