Can someone help me understand climate change?

[DontHurtTheIntersect]

I'm afraid I walked into this issue at the wrong time. I can no longer tell what is going on. I don't know if I should be skeptical or not. The issue has become so politicized, and I am untrustworthy of any information out there, because I don't know if people are twisting things or not.

tl;dr

Someone simplify the climate debate/non-debate

 

[Netheralian]

1. The climate is measurably changing.
2. CO2 (amongst others) is a greenhouse gas because it absorbs energy in the thermal spectrum
3. Humans produce CO2 (amongst other gases)
4. The atmospheric content of CO2 (also with the other gases) has measurable increased since the Industrial revolution
5. Conclusion - Anthropogenic climate change

 

[Aught3]

Also you should add that the increase in temperature doesn't correspond to any other known mechanism for changing global temperature.

 

[nemesiss]

1. The climate is measurably changing.
2. CO2 (amongst others) is a greenhouse gas because it absorbs energy in the thermal spectrum
3. Human activity produces (extreme) high ammounts of CO2 (amongst other gases)
4. The atmospheric content of CO2 (also with the other gases) has measurable increased since the Industrial revolution
5. Conclusion - Anthropogenic climate change

edited for improvement

 

[Squawk]

I don't know if I should be skeptical or not.

Always.


As for the rest, there are many factors that influence the climate. The sun is a prime driver of course, but there are many factors on earth. Just for a very quick list, consider such things as orbital variation, atmospheric content of various gases, volcanic activity, ocean currents, sun spot activity and even local weather.

The climate is an immensely complex bit of machinary, the scientists job is to try to puzzle out how it all fits. To do this, they make models.

The models try to take into account all known factors to the extent to which they influence climate. The models are then tested to see how they match up with real world data.

There are various data sets to play with. For actual temperature measurements we can go back only since records began, so we are dealing with not much more than a few human life times. For satelite measured data we can go back only a couple of decades. To go back further we must measure the temperature by proxy. Ice cores, tree rings, corals or even fossils can serve as measures of past climate history.

So, you take your model and you give it a set of starting conditions. Lets say you develop the model and then give it the starting conditions known from measurements takeen in 1850. Then you let it run and see what climate predictions it comes up with from 1850 to the present. Compare the prediction with the real world observed data and you test the validity of the model.

There are of course many problems. You can't test the model for unknowns. CO2 levels are increasing at unprecedented rates. We have seen higher CO2 levels in the past, and can measure the effects on climate by the proxies, but we have never seen the increase in CO2 at the levels it's currently going, particularly not with other factors such as deforestation.

So, we dealt with the problems, now what do the models show.

Well, the models to date show one thing clearly. Using only the known natural forces on climate in the models, you end up with models that do not account for the climate as observed for the past X years. Only when you include man made forcers (increase in CO2) do you achieve a model that matches with the observed data.

Now you have a model that includes all known factors (natural and man made), and it fits with the observed temperature data. So now you plug in start conditions for the present, and you run it to the future. The models then spit out various predictions, with given condence levels. Pretty much all models agree that if we continue to pump out CO2 at current levels we will experience warming of between 2 and 6 degrees by the end of the century, with the likely figure being around 4 degrees.

But, and this is the crux, we don't know for sure. And that is the problem. People, the public at least, don't like lack of certainty. They want black and white, yes or no, and it just doesn't exist.

The most comprehensive analysis of the data says that it's happening. Are the models flawed? Certainly. Do we understand all aspects of climate change? Of course not?

But, given what we do know, it is foolhardy to dismiss climate change. So yes, be a skeptic. I'm a skeptic in all things. Have a look around these boards, just yesterday there was a thread around here on the effects of the earths magnetic field variation on climate, something that I had previously not considered and which a quick search reveals is not well understood at all.

Whatever you do do, don't read the newspapers and form a conclusion. The newspapers are a waste of the paper they are written on for any scientific information.

 

[kf00kaha]

As Squawk says: always be skeptical.

I'm sure you have read about this 'Climate Gate' and such, promoted among others by Fox "News" (taken as example since they came up first when googling 'climate gate'). I'm not so sure though: I'm trying to become a scientist myself, and I've written far worse statements in presumably private emails about different ideas in my field of research... I still have to debunk them properly through the peer-review process before I can claim they are entirely wrong.

However, Squawk is quite accurately describing the process behind the support for global warming. There are some studies pointing the other way too, but the overwhelming majority of the scientific literature is in favor of global warming. The outcomes are on the other hand very much up to discussion, since we don't really know what's going to happen.

potholer54 have a very good playlist about climate change, where he goes through the scientific literature, also the skeptical part. I think that's a good starting point.

 

[creamcheese]

I happen to believe that humans are having a measurable effect on our climate, but regardless of whether or not you believe this, having the world switch to clean energy sources is a win-win situation, and there is no reason we should not be trying to do this.

Win #1-
If global warming is a man-made phenomena we will have prevented its spread, potentially saving millions of lives and billions of dollars [i.e. OMG THE POLAR CAPs MELTED AND WE ARE UNDERWATER!!!!!!1111oneone]

Win #2-
Fossil fuels, and to some extent nuclear fission will eventually exhaust all economically obtainable fuels sources, and if we have not converted to 'renewables' by that time we will be in the dark, quite literally. [Our supply of solar power is only limited by the lifetime of the sun. And of the universe if we move to other solar systems for power]

Win #3- [really only applies if you are an advocate of colonising space]
Fossil fuels are pretty much useless in space. They are not a very good rocket propellant, and do not drive the development of new technologies that would be useful for an space-faring species, whereas solar power and nuclear fission and nuclear fusion are quite useful.

 

[DontHurtTheIntersect]

I appreciate all of the comments. I at least know a lot more than I did then.

 

[Squawk]

I appreciate all of the comments. I at least know a lot more than I did then.

I'd suggest that you now know a lot more of what you don't know, which is the scary thing, and a great position to be in. The more you find out, the more you realise you haven't got a clue. I know bugger all, but fortunately I am aware of it. Most aren't, and the most dangerous people are those that think they know, but don't, and yet are in a position to have influence. The CRU stuff is the perfect example, poterholer54's vid on the subject is, as kf00kaha suggeseted, a great place to start for anyone not inclined to read the emails (they really are dull).

I listened to a radio programme yesterday with David Milliband (Uk climate change secretary), and his lack of knowledge was quite frankly scary. He was under the impression that all warming due to CO2 is man made. I tried to phone in when he said it, sadly I didn't get through. Fortunately he is sensible enough (apparently) to listen to the scientists opinions rather than form his own conclusions, but ffs have a clue at least. At least he recognises that his position is to act on the information he is given, not decide what the information means.

 

[derkvanl]

Maybe a little offtopic, but what I really miss in the climate discussion is all other kinds of pollution.

- How do the polluted rivers relate to the climate problem?
- What happened to the nuclear waste problem?
- What about all our chemicals?

I think the open discussion on the CO2 is a good, but people are too much focussed on putting all environmental problems as a result of our CO2 production.

1. The climate is measurably changing.
2. CO2 (amongst others) is a greenhouse gas because it absorbs energy in the thermal spectrum
3. Human activity produces (extreme) high ammounts of CO2 (amongst other gases)
4. The atmospheric content of CO2 (also with the other gases) has measurable increased since the Industrial revolution
5. Conclusion - Anthropogenic climate change

I do miss one important thing here. We destroyed major parts of the earth's forests and nature.

 

[Nogre]

It's already been said, but Potholer54 has a great series exploring the whole issue on Youtube. I'd recommend watching that series to get the serious science, rather than the politicized BS that does come from both sides.

 

[Niocan]

The earths climate has been changing the entire time it's been in existence, and like most things it evens itself out through a neat little trick called a CYCLE. The *only* difference this time, is that some people want you to think humanity is the source of this 'problem', so said people can implement a ridiculous tax scam based off of distorted lies and PR champaign's (social conditioning) of which are all based upon fear.

This is all far easier to understand then you might think... Look into the FOI2009.zip file for the leaked information. Of course, this view will be labeled as wrong and insane but it's ultimately up to yourself to decide; So choose, and always look further into what you believe to be true to test your own thoughts.

 

[kf00kaha]

Maybe a little offtopic, but what I really miss in the climate discussion is all other kinds of pollution.

- How do the polluted rivers relate to the climate problem?
- What happened to the nuclear waste problem?
- What about all our chemicals?

I think the open discussion on the CO2 is a good, but people are too much focussed on putting all environmental problems as a result of our CO2 production.

...

I do miss one important thing here. We destroyed major parts of the earth's forests and nature.

You're right, the focus is very much on the CO2-issue right now. This is mostly because it's easier to focus on one question at the time than look at the whole picture. And I agree, it's very unfortunate that it is so. However, if I recall correctly, the deforestation of the rain forest was brought up in Copenhagen (I think I saw a news article about it...). The EU at least tries to do something about the chemicals through REACH (I know it's not the best, but it's something, better than before). Regarding polluted rivers I think China imports technology from e.g. Sweden to do something at least (although far from enough).

Nuclear waste: I saw a blog a few days ago, stating that a top politician had said (oh I should really bother to look this up, but I don't have the time) that everything comes second to the CO2-issue right now. I think that sums it up fairly well...

 

[Squawk]

The earths climate has been changing the entire time it's been in existence, and like most things it evens itself out through a neat little trick called a CYCLE. The *only* difference this time, is that some people want you to think humanity is the source of this 'problem

Scratch that, change it to "all the evidence suggests that humanity is contributing a significant factor that is influencing the climate".

Seriously, if you want to present an argument, don't use an appeal to ignorance.

 

[Doc.]

rather interesting topic, never really knew much about this.

... having the world switch to clean energy sources is a win-win situation, and there is no reason we should not be trying to do this.[/i]

can somebody briefly explain what is a "clean energy"?

 

[kf00kaha]

'Clean energy' is in the ideal world electricity and/or heat coming from a 'source' (energy converter) that has supposedly no impact on the environment, i.e. no harmful emissions of any kind during the making of the 'source' itself, the 'production' of said form of energy during the lifetime of the 'source' and the scrapping of the 'source' after it stops working. Such 'energy source' doesn't exist, so 'clean energy' is a politically defined concept, mostly for sources of electricity that doesn't emit CO2 during the production of electricity, e.g. solar/wind power, water power, but also burning of 'energy forests' i.e. you plant fast growing trees that take up as much CO2 as you release (then the net emissions of CO2 are supposedly zero).

However, counting the emissions 'from cradle to grave', i.e. for the whole lifetime of the power station, including producing parts, assembly, production of electricity, maintenance, production and maintenance of distribution network, disassembly and scrapping of old parts, and of course all transportation in all steps (sometimes you even count how the means of transportation are manufactured, even the roads/railroads/airports...), etc etc., the net emissions are actually quite high for e.g. wind power plants, making them not so clean after all, if the way of production isn't changed. But this is all about how you count. Nuclear power for example, can be considered very clean in terms of CO2 emissions, unless you count the mining for uranium, not to mention other impacts than just the CO2 emissions...

See also http://en.wikipedia.org/wiki/Clean_energy

 

[Doc.]

thank you very much