global warming: salvaging fact from heaps of BS

[Edtharan]

I think our views on economics are different. I assume you are American???

Actually, I am an Australian.

 

Our opinion is that the USA got its economics very badly wrong. The US administration uses tariffs and subsidies to distort the economy in all sorts of ways - usually for the gain of whatever lobby group happens to be most influential at the time.

The problem here is not the subsidies (although it is bad for international markets), but the reasons those subsidies were implemented.

 

As you said, the subsidies are for the gain of whatever lobby group happens to be the most influential. These lobby groups don't necessarily have the economy as a whole in their best interests (and they shouldn't, they are there to make a profit after all).

 

usually these lobby groups want subsidies arranged so that their industry stands to make the most profit. In the case of solar technology, the existing power supply companies have a vested interest in current methods (they have money invested in the supply chains for their industry). They also want to appear as doing something altruistic (this doesn't actually mean they actually do something altruistic, just that they need to appear as being altruistic).

 

As the economics of it are very simple and well known, it would not be inconceivable that lobby groups would fund solar technology in such a way as to keep the prices high. It makes good business sense as it reduces the amount of competition for the product, while appearing on the surface to be an act that is an attempt to support the opposition (the appearance of being altruistic).

 

Way back in 1984, the NZ government dumped all tariffs and all subsidies. We now operate according to open competition.

Does the NZ government have any business support programs? If a large company goes towards bankruptcy, does the government step in and help (this has occurred several times in Australia in recent decades).

 

Does the government offer low interest loans to start up companies?

 

Do they offer tax breaks to certain industries?

 

Do they offer rewards or incentives for certain practices?

 

Do they tax some products more than others?

 

Is there any government own industries (like telecommunication industries, power companies, infrastructure, etc)?

 

These are all ways of indirectly subsidising industries.

 

Lets take this hypothetical scenario:

Imagine that a government want to encourage the use and development of solar technologies. They decide to implement a carbon tax as the figure that solar cells are a non polluting source of power.

 

They decide to implement the carbon tax on power industries that are not using non polluting sources. This raises the price of power. But they make non polluting sources exempt from this tax, in an attempt to lower the price of these technologies.

 

This may be hypothetical, but this is actually how most governments are implementing projects like this, so it is not too far from reality as far as hypothetical scenarios go.

 

Now, this is a kind of subsidy. The tax could have been implemented as an across the board tax on power, but then the government could offer a direct subsidy to non polluting power sources.

 

Making a source exempt form tax and making another subject to a tax is exactly the same as an across the board tax with a direct subsidy.

 

Also, this kind of indirect subsidy (tax exemptions), is subsidising the end product. This creates demand for the product without necessarily increasing the supply of the product. This increases the price.

 

Now, it might not look, to the average punter, that if the government offered the Silicone producers a direct or indirect subsidy (for silicon produced for solar technologies), of whatever type, then this would do more to reduce the costs of solar cells and for less price.

 

This indirect subsidy could take the form of carbon tax exemptions. As carbon taxes are being implemented in countries across the world, this offers ample opportunities to help reduce the costs of solar technologies by being smart with subsidies (indirect or direct, depending on the method you particular government uses). They already offer carbon tax exemptions to businesses that attempt to offset their carbon emissions. Why not offer it to companies that are attempting to offset virtually everyone's carbon emissions and in a way that makes the technologies cheaper?

 

If solar panels are limited by silicon availability, then increasing demand raises prices.

And increasing silicon availability reduces prices.

 

It is very likely that both these examples would reverse, and they would actually get cheaper in quantity, if new technology and extra investment is introduced to increase availability of silicon and uranium.

Hang on. Earlier you were arguing against moving to solar (and instead moving to Nuclear), because there was unknowns about whether or not technology would be able to develop a good solution. But here you are arguing for nuclear with the proviso that new technologies end up being invented.

 

You are applying a double standard here.

 

According to this last post of yours: It is ok for nuclear to need new technologies (and have the unknowns of it), but not solar.

 

Solar technologies can be implemented quickly with current technology. Price (according to you) is the main (but not only) barrier.

 

You have assumed that it is new technologies that are needed to reduce the costs of solar.

 

I have shown that this is not the case. Government spending (whether in the form of direct or indirect subsidies), can influence the price (yes some governments have a policy of non-subsidy, but wouldn't it be better to subsidies than end up with global warming?).

 

Depending on where the government actually spends their money, they can either keep prices high, or act to reduce prices.

 

I have also shown that current implementations of the Carbon Taxes and the Carbon Tax exemptions (and a lot of other indirect subsidy programs) are the wrong way to support cheaper solar technology as it is not making an increase to supply, but instead increasing demand.

 

However, if we are going to make 10,000 nuclear power stations, the cost per unit goes down. The cost would go up only if there was some limit on building nuclear power plants, and I do not think that applies.

Actually there is a limitation on nuclear plants. They require skilled workers, in both construction and operation. There are only a limited number of individuals that would be available to work on them.

 

Other industries pay more, so the only way you could get more skilled workers is to raise the wages for these workers. Also the initial shortage of workers (supply and demand) would crate a job market where by the workers would select the highest paid jobs. This would then form a base line wage and it would be very difficult for any employer to drop this wage later.

 

This would dramatically raise the costs of nuclear technologies if implemented on such a scale.

 

So yes, there is a limitation on nuclear power stations that would act to raise the price of nuclear power.

 

If the US government (and others) were to remove subsidies off other means of generating electricity, and solar panels became stars as a result, then I would applaud.

Actually most of the subsidies that are applied in other power generation systems is in the supply chain. Subsidies to mining companies (coal, etc) are exactly the thing I am talking about.

 

Governments are subsidising (directly or indirectly) the supply chain for the polluting power generation systems, but are not subsidising the supply chain for non pollution systems like solar.

 

As Solar does not require an ongoing input of raw materials, there doesn't seem to be a supply chain. But there is in the production of the solar panels and this is where the most influence can be.

 

In a Coal fired power station, the greatest cost is not the plant itself, but the coal needed to keep it operational.

 

In solar technologies, the greatest cost is not in keeping it going, but in the plant itself.

[iNow]

In solar technologies, the greatest cost is not in keeping it going, but in the plant itself.

 

And that's when you call these guys to get a SunFab installed:

 

http://www.appliedmaterials.com/products/solar_sunfab_3.html

 

A few ideas they mention decrease installation costs of solar farms by ~17%.

 

 

 

They have a really cool multimedia presentation of how the module production line looks/feels:

 

http://www.appliedmaterials.com/products/solar_multimedia.html

Edited August 27, 2008 by iNow

[SkepticLance]

To Edtharan

You have presented some good arguments from the view point of economics. I would love to debate it point by point, but I think that will take us substantially off the thread topic. Perhaps another thread??

 

A couple of points, though.

 

Yes, there are indirect subsidy equivalents, and the current New Zealand government, which is a little left wing, has been guilty of using some of these. In my opinion, those are seriously undesirable also. It is probably true that there is no such thing in the world today as a nation untainted by some form of subsidy - more is the pity.

 

I am not keen on the concept of carbon taxes. I think you can appreciate that they are wide open to abuse. I think there are much better ways of achieving the needed goals. And yes, they can be used as a form of relative subsidy. Again, not something that I consider desirable. I would like to see all power generation technologies on the hypothetical 'level playing field' so that rational choices can be made uninfluenced by government or lobby group bias.

 

You said :

 

"Hang on. Earlier you were arguing against moving to solar (and instead moving to Nuclear), because there was unknowns about whether or not technology would be able to develop a good solution. But here you are arguing for nuclear with the proviso that new technologies end up being invented.

 

You are applying a double standard here."

 

You may have misunderstood my point. As things stand right now, nuclear is a proven and practical and economic technology. Solar is proven, but not economically competitive as of right now. I was making the point that nuclear, along with other technologies may (probably will) improve further, and especially in terms of making nuclear fuel more readily available. Solar will improve also, but nuclear is ahead in economic terms at present.

 

On the need for skilled workers for nuclear.

Yes, they are needed, and if we were to start building 10,000 new plants today, that need would be critical. However, it is a temporary shortage only. Skilled people can be, and will be trained. It takes 20 years for a nuclear power station to go from conception to commission, and it takes a lot less time than that to train skilled workers.

[Edtharan]

On the need for skilled workers for nuclear.

Yes, they are needed, and if we were to start building 10,000 new plants today, that need would be critical. However, it is a temporary shortage only. Skilled people can be, and will be trained. It takes 20 years for a nuclear power station to go from conception to commission, and it takes a lot less time than that to train skilled workers.

Building nuclear plants also needs skilled workers. There are many dangerous substances involved and specialised workers are needed.

 

This means that the lead time for the plants would also have to include training the workers (say around 3 to 5 years). This would be on top of the time it takes to build the plants.

 

Not only that, if we keep on the "Business as usual" for the next 20 - 25 years, it might be too late for the power stations to have an effect.

 

If we had started building the nuclear power stations 10 years ago, it might have been more feasible, but time is against us. 20 years is just too long for us to wait before we can greatly reduce/eliminate carbon emissions from electrical power production.

 

Most conservative models of global warming put the tipping points at around 20 years (or less). And as you yourself have pointed out, the models tend to underestimate the rate that the effect of Global Warming are occuring.

 

If conservative models predict 20 years and their performance is usually to over estimate the time, then it looks like 20 years is not enough time before we need to start making a difference.

 

I would like to see all power generation technologies on the hypothetical 'level playing field' so that rational choices can be made uninfluenced by government or lobby group bias.

The problem with open markets is that sometimes they don't always produce the best results. They will usually produce the best results in terms of price, but sometimes price is not what is important.

 

It is not only governments that can effect prices with "subsidies". Businesses can too. If the market is dominated by a near monopoly (say the reliance of coal and oil fired power) in a sector (energy), then these industry giants can have a similar effect to governments by choosing which sectors they support (give loans too, buy shares in, etc). The economic power these large industries wield is large enough to challenge the economic power of individual purchasing (especially if the individual purchases are divided amongst multiple goods/services).

 

As with governments, big businesses can fund end products without supporting the production pipelines to increase demand and raise/keep prices high. They can also put spin on it to make it seem like they are being altruistic.

 

Big organisations would not ignorant of this, so it is very possible that they undertake this behaviour. It makes good business sense in that you are ensuring your market.

 

Also, because an industry might not be completely financially feasible, but necessary (or desirable), it might be necessary for governments to subsidise these industries to bring about the needed change in the market.

 

An example is with the CFCs. It was expensive to change from using CFC to other propellent. So many governments subsidised the change over. Eventually, because the supply chain was developed, the new chemicals became cheaper than the CFCs and it is now more economically feasible to use Non CFC propellants (although in some countries they still use CFC because they didn't make the change).

 

it is like I said, it is not like this kind of action has never been done. And experience with it had been successful in the past.

[scalbers]

Just a play on words, is that we are all solar and fusion powered. After all, fusion in the sun created energy that shone upon the Earth. This fed the plants that later became buried and became fossil fuels - that we use today.

 

Back to the discussion at hand. Solar and wind are now very economical at least in the favored areas. This would be the desert SW US for solar (consider PG&E's announced large plant). NanoSolar's thin film is also very economical (about break-even with coal) and avoids the cost issues of silicon.

 

Wind energy is abundant in the high plains of the US. With good transmission lines this could become even more significant.

 

And as for fusion power plants, why is the US zeroing out its funding for ITER in the latest congress?

[SkepticLance]

Edtharan is correct in saying skilled workers are needed for making nuclear power plants. However, that is not an excuse to avoid starting the process, including training more workers. Realistically, we are not going to see 10,000 plants under construction, even if that is what is needed. However, we can get a few hundred under way, and work on training those people who will be required for the next lot.

 

My views would not be a threat to solar energy even if those ideas were totally shared by the people in politics and business who make all the important decisions. I am fully supportive of massive investment and development of solar energy, along with a wide range of other energy developments. I just do not see it as being a suitable alternative for mass electricity generation in the short to medium future. Some day, perhaps - and we continue investing towards that day.

 

The time factor for global warming disaster, if at all, is not known. Edtharan thinks 20 years will be too late. I doubt it.

 

It is easy to forget how minimal global warming has been. Sure, the last 30 years has seen warming at an unprecedented rate. But 30 years, or even 60 is a very short time in global climate change. Total warming, as a global average, is still less than 1 Celsius since the end of the Little Ice Age, and is only about 0.5 Celsius more than the average global temperature over the past 1000 years. It is still 2 Celsius less than the maximum reached during the previous interglacial period 120,000 years ago.

 

This was shown recently here in NZ. We have just had the biggest snowfalls in recorded history. Mount Ruapehu - our most popular ski field - has a snow base of 4.5 metres. They have records going back to the late 19th Century, and this is the deepest ever!

 

This is NOT a denial of global warming. I am just trying to put it into perspective. If we think in terms of signal to noise ratio in warming, the noise is still massively greater than the signal. The season to season variation is much, much, much greater than the minimal 0.8 Celsius overall average global warming.

 

The next few decades will see further average warming, but it will still be much less than the variation season to season. In other words, we have the time to take required action, and panic measures are absolutely not needed.

 

Climate models, when they first came out, predicted warming in Antarctica. That has not happened, and the main body of this continent has actually shown cooling. The modellers have tweaked their algorithms and now model the cooling, but this indicates the weakness of models, when dealing with such an immensely complex set of thousands of interacting systems.

 

To make a prediction that we have only 20 years before a tipping point is simply laughable. Especially in view of the minimal warming that can happen over such a short period of time.

[scalbers]

Sounds like a good overall assessment of energy and some aspects of warming. However I would suggest differently about the amount of time we have. If we wait until the planet warms a certain amount we want to tolerate before deciding it's too warm, then it's too late. There is a lot of inertia present in several ways. This includes ocean heat inertia, carbon residence time in the atmosphere/oceans (thousands of years to get it all out), and societal inertia in reversing the trend in emissions rates. There is also inertia in the sense of the tipping points of ice cap melting and permafrost release. If you buy Jim Hansen's suggestion to return to 350ppm CO2 then it's already too late and we need things like biochar to reverse the CO2 concentrations.

 

Another way to consider this is that almost any emissions we make will increase the long term CO2 concentration in the atmosphere/ocean system as the sinks are likely inadequate. If we say the CO2 will eventually be absorbed in the oceans we still have the issue of ocean acidification.

 

A good way to frame this discussion is how much eventual warming (and eventual CO2 levels) shall we tolerate. I would personally like to keep the eventual warming to be no warmer than today. This would suggest the CO2 concentrations roughly around the 350ppm value.

 

And incidentally, snowfall in some areas actually increases with warming, since warmer air can hold more moisture.

 

Steve

Edited August 27, 2008 by scalbers

[swansont]

To swansont

Re raising or lowering prices of power generation with a greater number of plants.

 

There are two principles here.

 

1. If something is in limited supply, then increasing demand will raise prices. That is why gold and diamonds are so expensive.

 

2. If something can be made in more or less unlimited amounts, then increasing demand increases number of units made which lowers prices. The old 'cheaper by the dozen' principle.

 

If solar panels are limited by silicon availability, then increasing demand raises prices. Similarly the price of uranium goes up with increased demand, because the availability is limited. It is very likely that both these examples would reverse, and they would actually get cheaper in quantity, if new technology and extra investment is introduced to increase availability of silicon and uranium.

 

However, if we are going to make 10,000 nuclear power stations, the cost per unit goes down. The cost would go up only if there was some limit on building nuclear power plants, and I do not think that applies.

 

I disagree. As has been pointed out, skilled/certified workers are as much a commodity in this equation as polysilicon is.

 

Edtharan is correct in saying skilled workers are needed for making nuclear power plants. However, that is not an excuse to avoid starting the process, including training more workers. Realistically, we are not going to see 10,000 plants under construction, even if that is what is needed. However, we can get a few hundred under way, and work on training those people who will be required for the next lot.

 

One problem here is that companies will not hire on and train additional workers unless they have a firm commitment to actually build the plants and the components that go into it. You can't just buy the valves and piping you need at your local plumbing supply store.

 

So initially you'll have demand outstrip supply, and nobody will bid low, because they don't have to. If there's a firm promise of sustained construction, they will ramp things up. But as long as you're guaranteed getting contracts because of high demand, the prices will not drop.

[SkepticLance]

Swansont

The economic arguments you and I both presented are sound, but there is a datum missing. What percentage of the cost of constructing a nuclear power station is the cost of skilled labour? If skilled labour costs twice as much, how would that impact on the cost of the plant? For this, I am talking only about skills relating specifically to nuclear plant construction - not the more common skills related to builders, electricians etc.

 

We need the answer to determine if that factor is significant. It is like those who argue that nuclear power gets too expensive if the cost of U235 increases, without realising it is only 10% of the cost of the electricity generated.

 

Bearing in mind that 'unskilled' labour will be as abundant and 'cheap' as before the nuclear plant construction, I would suspect that the cost of skilled labour would not be a major fraction of the cost of total construction.

[Edtharan]

I am fully supportive of massive investment and development of solar energy, along with a wide range of other energy developments.

I am advocating Smart investment in these energy industries.

 

Solar and wind, although a little more expensive, are actually operational. Alternatives, like geothermal are still experimental.

 

As concerns you have, experimental technologies carry a risk, where as technologies that are already implemented have a much lower risk factor.

 

The time factor for global warming disaster, if at all, is not known. Edtharan thinks 20 years will be too late. I doubt it.

Based on what we know of long term influences, we can know one thing: At a certain point, if the temperature of the Earth raises too much a tipping point will be encountered and this will set off a chain of events that will lead to further temperature increases without any further need of human activity (but human activity can still contribute to this).

 

The exact details, like how hot it will get, or at what the critical point is, we don't know precisely. But, this does not mean that e don't have a range of values that it could be.

 

The range of values for the tipping point range from 2000 to 2050. Yes, the range does indicate that the tipping point could already have been reached. 2025 is just in the middle of it (and 20 years form now will be 2028).

 

It is easy to forget how minimal global warming has been. Sure, the last 30 years has seen warming at an unprecedented rate.

Global Climate systems are non linear systems. That means changes to them do not follow a straight line when graphed (even if you only graph the average).

 

One such graph that can occur is that of exponential growth. In this you would not expect to see much variation early on, but then the graph will start to raise up quickly.

 

In the "last 30 years has seen warming at an unprecedented rate", could be a blip in the data, but it could also be evidence of exponential growth.

 

you dismiss 30 years as being insignificant, but I (and many others) think otherwise.

 

The industrial revolution began in the late 1700s, but it wasn't until the 1850s that humans rally started to influence the amount of CO2 in the atmosphere.

 

This means that we have had only 158 years of significant influence on CO2, most of which has occurred in the last 60 or so years.

 

Lets look at the proportions that 30 years is in this scheme of things:

 

30 years is roughly 20% of the time that we have been significantly influencing CO2 levels. That is 1/5th of the time.

 

Lets put it in another statistic. Just say that 1 in every 5 dollars in your bank account were to disappear, would you consider this to be a significant proportion of your money that has disappeared? I bet you would.

 

Total warming, as a global average, is still less than 1 Celsius since the end of the Little Ice Age, and is only about 0.5 Celsius more than the average global temperature over the past 1000 years. It is still 2 Celsius less than the maximum reached during the previous interglacial period 120,000 years ago.

These events you are comparing the warming to occurred long in the past, long before humans began to influence CO2 levels. In fact, because these occurred so long in the past, it kind of tells us that until recently the climate was stable for a long time. But then we start pumping CO2 into the atmosphere and then in a short time global temperature rises to level it hasn't seen for thousands of years, or even hundreds of thousands of years.

 

In the last interglacial period, it took hundreds if not thousands of years to go from low to the high period. Here it took us only what, 150 years?

 

It is not just the total temperature, it is also the rate that is worrying.

 

This was shown recently here in NZ. We have just had the biggest snowfalls in recorded history.

Are you still going on like this. I though we had already discussed this and come to the conclusion that specific incidents like this are not really admissible as evidence for or against global warming?

 

Actually you your self have used this as an argument against evidence for global warming. Another double standard. You can use specific incidence to prove that GW is not happening, but we can't use specific incident to prove it is.

 

Either we can or can not use specific incidences as evidence (for or against). I for one say that we can't.

 

This is NOT a denial of global warming. I am just trying to put it into perspective.

One, specific incidences do not "put things into perspective". At best they are a red herring argument, at worst they are a deliberate attempt at a Strawman.

 

Perspective is this: In the last 1000 years there has been very little variation in temperatures. In the last 150 years there has been a significant increase in temperatures (as compared to the usual fluctuations), and in the last 30 years the rate of temperature increase has been higher than at any time in the last 150,000 years (or more).

 

Also the amount of Snow is not actually indicative of warming. In fact, if it is too cold, it won't snow. The important measure is the height of the snow line, has it gone up or down?

 

If it is too warn, it can't snow as snow is frozen water (ice). If the temperature consistently rises above 0 degrees, then the snow will melt. This defines the snow line. If the atmosphere's temperature is rising, then the snow line will get higher. If the atmosphere is cooling then the snow line will descend.

 

Also, as this is Global climate change, we can't just limit our measurement to a single mountain (or mountain range even). We have to look at global trends.

 

More snow does not mean colder climate (warmer air hold more moisture).

 

So not only is your "measurement" a Hasty Generalisation, it is also not an accurate measurement for atmospheric warming.

 

Yes it is not a denial. It is irrelevant to the discussion at hand.

 

If we think in terms of signal to noise ratio in warming, the noise is still massively greater than the signal.

It is possible to get a signal through even on a noisy line, as proven by Claude Shannon.

 

Although the noise is high, the strength of the signal (evidence) is now sufficient for us to get a general idea.

 

Interestingly, a lot of the "Noise" (the fluctuations in temperature) turns out to actually be "Signal". Because the climate systems are complex and non linear, we expect certain behaviours form them. It is these behaviours that cause fluctuations in the output (data) and also mean that you will get localised regions that "buck the trend" so to speak.

 

Two such behaviours are:

1) Small errors grow to big errors

2) Attractors

 

The first means that short term predictions are usually pretty good (in terms of climate systems this amounts to a few days). The second, "Attractors" means the system has states that are relatively stable, but that if more than one exists, then it can sometimes switch between them if the system finds it self closer to one or the other in the phase space. This means that long term predictions can be made if we know where about in phase space we currently lie and in which direction we are moving within that phase space

 

Looking at historical trends (over millions of years), it appears that the climate systems have 3 major (and many minor) attractors.

 

There are:

1) Glacial

2) Interglacial

3) Warm

 

We are in an Interglacial period now. The climate systems (in the last 150 years) have become increasingly unstable. This means that we might find ourselves closer to one attractor or another and this will cause a change in climate state. This situation is also called a "Tipping Point".

 

We also know that the temperature is increasing, so this indicates that we are headed for the Warm attractor.

 

Now the Phase Space is not flat, and there exist local minimums that can direct the system along them. So we might first start moving towards the Warm attractor, but end up in the Glacial Attractor.

 

The question is, is there enough energy caused by increased CO2 to get us out of any local minima that could act in such a way? Also, is there enough influence by CO2 (and other greenhouse gasses) to push us close enough to the Warm (or Glacial) states for them to become the dominant attractor?

 

This can be answered by: If we keep putting CO2 into the atmosphere, then it will get warmer. The more CO2 we pump into the atmosphere the stronger the push towards the "Warm" attractor we will have.

 

The conclusion is: If we keep business as usual, then we will end up in the warm state sooner or later.

 

Long terms predictions, despite noise, are therefore possible.

 

Knowing more about the amounts of change necessary for these to occur is what allows us to put numbers to them (I don't know the numbers so I can't actually go through and make an exact - or near enough to - prediction). But even if we aren't sure of the details, we know enough about the system to make general predictions.

 

Looking further at historical data, we find other trends. The first is that the system tends to move from the Warm to the Glacial state. But then it will move from the Glacial to the Interglacial state. From the interglacial state it will move back and forth between the Glacial and Interglacial states, or to the Warm state.

 

What we don't see often is a move from the Warm state to the Interglacial State. This means that if we make the shift form or current Interglacial state to warm, it is extremely unlikely that we will go back to this stable period that we are now in.

 

In the past, the move from Interglacial to Warm has occurred when the temperature of the Earth goes above a certain threshold: A Tipping Point.

 

If current warming trends occur in a non linear fashion, then by 2050 to 2100 will will pass this tipping point and be headed towards a Warm period. But the lag due to CO2 emissions seems to be around 30 to 50 years.

 

Now this is why some people think we might have passed the tipping point already (although this is worse case and probably alarmist, I'll use it as an example of how it can occur).

 

If the Tipping Point for the Warm state is around 2050, then a 50 year lag in emissions to effect will have put the point at which the amount of CO2 emitted that will make us cross this Tipping Point will already have occurred.

 

At best case scenario, the Tipping Point is in 2100 and a lag time of 30 years puts the critical emissions point in 2070.

 

Now lets take the average: 2075 as the tipping point and a 40 year lag. This then places the critical point in 2035.

 

However, current evidence is starting to point to a tipping point much closer to 2050 than 2100, but the lag time still seems to be around 30 to 40 years.

 

If we look at what the evidence is pointing to (although this could be wrong), it puts the critical point somewhere between 2010 and 2020.

 

The more precise we know the lag, the more precise we know the variation. The more precise we understand the tipping point, the more precise we can be about when the critical time is.

 

We can get the data about the lag based on historical observations of the climate and how it is responding to greenhouse gasses.

 

However, the Tipping Point is is a bit more problematic as to understand it we have to understand the system. Essentially, map out the Phase Space.

 

This involves looking at what systems within the larger climate systems can have an influence on the general trends.

 

System like the Albedo of the poles, the CO2 and other greenhouse gasses emitted from melting tundra or how particulate matter in the upper atmosphere reflects sunlight and provides cooling. It is identifying and understanding how these feedback,loops, both positive and negative, interact with each other that is important here.

 

We can take a look at certain events and situations and these allow us to work out what these systems are doing. Of greatest concern are certain positive feedback effects like the melting of the poles and the melting of the tundras. These act as accelerators towards the warm state.

 

As these systems are complex and share the same properties of all complex systems (small errors become big errors and Attractors) we can make short term predictions (months) and long term predictions (years) about them.

 

One of the attractors is that as they melt the encourage more melting by increasing the temperatures. In the case of the ice caps this is through absorption of heat by water and reflection by ice. The less ice, the more ocean is exposed and so the more local warming (with some global warming too). With the tundra, when it warms the vegetation frozen in it starts to decompose and release methane and other greenhouse gasses. This is not an immediate effect, unlike the the ice caps, so there is a lag. Also it is not necessarily a local effect and will be more global (long range) than the ice caps in its final effect.

 

There are many such feedback loops, and we are only just beginning to understand them, but what we do know is leading us to conclude that the critical time is close.

 

Sorry about the long post, but I know that if I had just responded to your argument about there being too much noise in the data, by simply stating that there wasn't. You would not have understood and would have had a lot of your misconceptions addressed.

 

I have taken this time and effort to go into a lot more detail so that you can try to understand why you are wrong, not just get told that you are wrong.

 

Events like the unexpected break up of the Antarctic ice sheet are worrying because these events were predicted to occur later rather than now. This creates uncertainties as to the accuracy of the timing in the models use to predict these events. But rather than this unpredictability being a good thing (ie that it might mean we have more time), the fact that they occurred earlier indicates that we might have less time than we think.

 

Events such as the loss of ice at the North Pole and the break up of the Antarctic Ice sheets was not predicted until around 2020 to 2040, but they have occurred now. These, in the model were indicators that the Tipping Points had been Reached. This is why it is so concerning now. It raises the spectre that we may actually have already crossed the Tipping Points.

[SkepticLance]

To Edtharan

 

Quite a long post you entered, but at least you use short paragraphs. I commend you for that. Too many people write ultra long paragraphs, or none at all, making understanding much less likely.

 

You talk a lot about tipping points. I am not quite sure of exactly what you are saying. It sounds to me as if you are using the term to describe positive feed-back scenarios, rather than true tipping points.

 

On positive feed-back, I have to point out once more that there are as many hypothetical negative feed-back mechanisms as positive. In the last hot time I mentioned, 120,000 years ago, when it got 2 Celsius more than at present, the warming reached a maximum and then cooling set in. This is more characteristic of a negative feed-back mechanism than positive.

 

A warming of 2 Celsius, assuming current warming rates, would take 110 years. To take as little as 50 years would require warming rates to more than double. Since there was no 'tipping point' 120,000 years ago with a temperature 2 Celsius warmer than at present, it seems unlikely that we will see one now for many decades. I tend to regard these positive feed-back ideas leading to 'tipping points' as simply some doomsday ridden theorists hobby horse.

 

They may happen, but there is no empirical evidence to suggest it could happen in the near future. We need a time line of 100 years plus.

 

It would be rather nice to see some of the hypothetical negative feed-back mechanisms given some weight also. However, that would ruin the fun of those who love a dark pessimistic picture of the world.

 

You suggest warming is exponential. You are right, but you have the curve inverted. The response to CO2 is indeed exponential, but negatively so. A doubling of CO2 leads to a warming that is substantially less than double. An exponential increase in CO2 may lead to a warming that is purely linear.

 

Your description of temperature change over the last 1000 years is not correct. Around 1000 years ago, the temperature was marginally cooler than the present as a global average. Around 1250 AD, cooling set in, of about 0.5 Celsius global average. Around 1750 to 1800 AD, warming set in, and slowly raised temperatures around 0.5 Celsius, by WWII. Over the last 30 years, warming has been about 0.3 Celsius.

 

The first part of the warming, of 0.5 Celsius can be seen as a return to 'normal' conditions. Only the last part, of 0.3 Celsius can be regarded as exceptional. The earlier warming was seen as early as 1800 AD, with a number of geologists alarmed at the melting of glaciers.

 

If we look at global temperature over a longer period - the current ice age of one million years - we see an interesting pattern of glacial and interglacial changes. There is an interglacial roughly each 100,000 years, plus or minus about 20,000 years. The peak temperatures of these interglacials have been increasing. If the current interglacial follows the same pattern, we can expect its peak to be warmer than the last one. And its peak was, as I have said, 2 Celsius warmer than the present. If current warming follows the 'natural' trend, we can expect it to peak out more than 2 Celsius than the present, even without human input.

 

The current ice age is not, of course, the normal climate of planet Earth. The norm is considerably warmer than the interglacials. Most of the evolution of life on Earth has taken place at temperatures well above that which we have at present. This is not a rationale for approving warming, but an indication that the level of warming we currently get, and can expect for many decades to come, is not actually disastrous. Life thrived in the past at higher temperatures, and can be exected to continue to thrive, if the world warms beyond normal interglacial levels.

 

We have time. Humanity will need to reverse CO2 levels, but not in the next decade as many catastrophists will preach. I suspect we have at least 50 to 100 years to get our act together. Yes, we need to get started on this. But no. We do not need to institute panic measures. Careful management of change is needed.

[Edtharan]

Quite a long post you entered, but at least you use short paragraphs. I commend you for that. Too many people write ultra long paragraphs, or none at all, making understanding much less likely.

I agree, too many people don't have good communication skills. It takes effort to learn, but once learned it is not difficult to apply.

 

I know I tend to write long posts (on occasion ), but I do try to make them not to difficult to read.

 

You talk a lot about tipping points. I am not quite sure of exactly what you are saying. It sounds to me as if you are using the term to describe positive feed-back scenarios, rather than true tipping points.

Tipping points are an artefact of multiple attractors. Positive feedback can cause the system to swing. Too much and the feedback loop can push the system into a new attractor. Negative feedback loops tend to keep the system in the attractor, but can still cause the system to move between them if the values the negative feedback loop seeks is close to an attractor.

 

Positive feedback loops tend to destabilise a system, which can flip it into another state, and negative feedback loops tend to make the system settle on one state or another.

 

What I am saying is that the positive feedback loop will tend to draw us towards the tipping points by destabilising the system (large fluctuations push the system away from the stability of the attractor).

 

On positive feed-back, I have to point out once more that there are as many hypothetical negative feed-back mechanisms as positive. In the last hot time I mentioned, 120,000 years ago, when it got 2 Celsius more than at present, the warming reached a maximum and then cooling set in. This is more characteristic of a negative feed-back mechanism than positive.

Yes there are negative feedback loops, and they are important, but what is of concern is not so much these, as left to themselves they won't "rock the boat" so to speak.

 

In complex systems you can use an analogy of temperature to describe a system. If there is not much variation in the system state, then the system can be considered cool. Just like in a gas, if the particles are not moving around much, then the gas is cool.

 

But if the particles in the gas are moving around quickly, then the gas is Hot. As is a system. If there is large variability in the system, then it can be considered hot.

 

this isn't just an analogy, in many systems (like the climate system) heat (energy trapped in by greenhouse gasses) actually is the thing that can drive these fluctuations.

 

However, it is not just temperature that is important. It is also the rate at which the energy increases that cna make the difference, as well as the specifics of that energy increase.

 

It is a bit like super heating water. It is possible to heat water up beyond its boiling point if you do so slowly and don't disturb the water and then cool it down again without causing the water to boil. But if too much agitation or you heat the water up too quickly it will boil.

 

Such as it is with the climate system. A slow warming can distribute the energies (heat , motion, etc) and runaway effects can be avoided. The system is very unstable in these situations, but according to models it can be done.

 

But if you heat the climate too quickly, then it will "Boil" and undergo a rapid phase change (move quickly from one state to another).

 

I mentioned it before, in my last post, that heating the climate too quickly could be bad (although I didn't explain it then as my post was getting too big already ).

 

A warming of 2 Celsius, assuming current warming rates, would take 110 years.

If the current trend is linear, yes. If exponential, or non linear, then this assumption would be wrong. As far as we know, the climate system is non linear. This indicates that we can't just accept current warming rates as a predictor of future warming rates.

 

Since there was no 'tipping point' 120,000 years ago with a temperature 2 Celsius warmer than at present, it seems unlikely that we will see one now for many decades. I tend to regard these positive feed-back ideas leading to 'tipping points' as simply some doomsday ridden theorists hobby horse.

Tipping points are a well studied phenomena in complex systems. One problem with your response is that complex systems are well... complex .

 

What it means is it is very difficult (not impossible) to look at the past behaviours and see one behaviour and simply state that the system will behave in exactly the same way in the future.

 

Instead, what you have to look at is the processes that went on, not just one degree of measurement. Usually this involves looking at lots of measurements in different situations and looking for patterns of behaviour that emerge out of the data.

 

For instance: If the build up of plant matter in permafrost didn't occur (or there was less of it), then when the temperatures increased, there would not be a release of greenhouse gasses when it melted. As no extra greenhouse gasses would have been released, there would be no extra warming due to this event.

 

Or, if the warming was slower, then certain biological systems could have evolved to take advantage of increased CO2 (like trees) and thrived in the new environment. If it happens too quickly, these slow moving negative feedback loops will not be able to kick in in time and so not be able to stop a runaway effect (this is why warming speed is an important factor in determining the effects of GW).

 

Another possibility is that the system was actually heading for a cooling (going from warm to cool). The direction of the instability is important in this case (direction as in towards a particular attractor in the phase space). As there are many system involved, not just a single Global Climate system (the global system is made up of these individual systems), then if th4ese systems were heading for a cooling, then excess energy would have been dumped into the atmosphere giving a brief period of warming, but then the "inertia" of the other systems would have pulled it back towards the cooling.

 

We have to look at the processes that went on 120,000 years ago to really be able to understand the differences between now and then. Just because it did manage to get 2 degrees warmer and not enter a tipping point could be down to a lot of things. I don't really know enough about this period to say exactly what occurred, but I do know that just because temperature was 2 degrees higher dose not mean that the situation was the same.

 

It would be rather nice to see some of the hypothetical negative feed-back mechanisms given some weight also. However, that would ruin the fun of those who love a dark pessimistic picture of the world.

Yes, it is true that positive feedback effects have been the main topic of discussion here, and among other groups. But this is because they are the factor that we can measure to determine the instability of a system. It is also harder to identify a negative feedback loop unless there is already instability in the system.

 

This means that the first feedback loops to be identified will usually be the positive ones, where as the negative ones require closer examination to detect.

 

As climate change is concerned about the instability of the system, then naturally the source of that instability will be important to understand.

 

Also, as I said in an earlier post, tipping points occur when the negative feedback loops are overwhelmed by the positive feedback loops. This effect will break loops and create others. This is what the phase change and attractors are all about (it can also mean that loops that exist now didn't exist the last time the system was in this state - talk about complexity ).

 

We know that there are Negative feedback loops in the climate systems, and we sort of know their limits. Looking at the historical data we can see the kinds of fluctuations (amounts and rates) that have occurred. The problem is that we are entering territories that only really have occurred during rapid climate changes in the past. The rate and amounts are very similar (and in many cases exceed) times of rapid climate changes in the past.

 

So it is not so much that the positive feedback loops exist, they really just help our understanding of what is happening, but it is the fact that what we are seeing is so similar to rapid changes in the past.

 

You suggest warming is exponential. You are right, but you have the curve inverted. The response to CO2 is indeed exponential, but negatively so. A doubling of CO2 leads to a warming that is substantially less than double. An exponential increase in CO2 may lead to a warming that is purely linear.

This is quite possible, but temperature is not the only measurement or effect of global Warming.

 

We have discussed this several pages ago in this thread.

 

Global Warming is misnamed (the name was given before they know much about complex systems). It is really: "climatic instability due to the accumulation of energy in the climate systems due to greenhouse gasses that prevent radiative emission of that energy".

 

Global Warming is also a lot easier to say.

 

This excess energy can turn up as atmospheric and/or oceanic warming, but it can turn up in a lot of other ways too.

 

Changes in ocean current and air currents, variability in weather patterns. Shifts in weather patterns (like increased snow falls, etc), and a lot of other ways.

 

However, as you said: "Sure, the last 30 years has seen warming at an unprecedented rate.". To me this does not sound like a linear increase in temperature. You are actually contradicting yourself here.

 

Your description of temperature change over the last 1000 years is not correct. Around 1000 years ago, the temperature was marginally cooler than the present as a global average. Around 1250 AD, cooling set in, of about 0.5 Celsius global average. Around 1750 to 1800 AD, warming set in, and slowly raised temperatures around 0.5 Celsius, by WWII. Over the last 30 years, warming has been about 0.3 Celsius.

In the very paragraph before this, you state that warming has been linear. But here you say it is not. You need to look at what you are saying. You keep contradicting yourself.

 

But lets look at this. This data says that since mass industry was developed, there has been an increased rate of warming. Not only that there was an actual cooling going on just before the industrial revolution, and then it turned into a warming.

 

Doesn't this data actually support Global Warming and that Humans are the main cause. The increases in temperature seem to match up with when there was a change in the amounts of greenhouse gasses produced.

 

It is also the description that I made.

 

The industrial revolution started in the late 1700, but industry and CO2 production was increasing before the revolution began. At this point your data says that the Earth change from cooling into a warming. It is a bit of a coincidence don't you think.

 

Next you say that from WWII there has been an increase in the rate of warming, which just so happens to also coincide with big changes to industry (increased mass production, mass power generation though coal, etc).

 

I don't think you are actually looking at your data. It actually supports what I am saying, not as you seem to think refutes it.

 

If we look at global temperature over a longer period - the current ice age of one million years - we see an interesting pattern of glacial and interglacial changes. There is an interglacial roughly each 100,000 years, plus or minus about 20,000 years.

Yes. I said that the data supports a move between the Glacial and Interglacial states. But not a move between the Glacial to warm (but warm to glacial or interglacial to warm is supported).

 

The Interglacial state appears to be an unstable "halfway" point between the Glacial and Warm states. It also appears harder to move from a glacial state to a warm state as once it starts to move form a warm to a colder state, then the system seems to rapidly change without passing through (or maybe passing through so quickly as to not leave much of a geological record). It appears that there are negative feedback loops that pull the Earth's climate system back towards a cold state.

 

However, it also appears that once the climate is disturbed enough to move the state out of the interglacial state, it will rapidly switch to the new state.

 

In the end, a glacial state could be worse for us than a warm state. In glacial states, more water is locked up in ices, and the colder air does not hold as much moisture. This means dryer weather with less rain fall and that means less crops can be supported.

 

So based on what we know of the climate systems, if we disturb the interglacial state too much we will either end up in a warm period, or a glacial period. Neither of which will be good in the short term, and the glacial period could actually be worse than a warm period.

 

The current ice age is not, of course, the normal climate of planet Earth. The norm is considerably warmer than the interglacials. Most of the evolution of life on Earth has taken place at temperatures well above that which we have at present. This is not a rationale for approving warming, but an indication that the level of warming we currently get, and can expect for many decades to come, is not actually disastrous. Life thrived in the past at higher temperatures, and can be exected to continue to thrive, if the world warms beyond normal interglacial levels.

Actually if you look at the fossil records of the times (for tens of thousands of years after the warming events), there is actually a loss of biodiversity as extinctions occur. Basically, life that evolved in a different climatic period tends to have trouble adapting to rapid climate changes.

 

Over time however, a warmer period is better for life, but that take tens of thousands of year to develop through evolution. Basically warm periods are good for life that has evolved for them, but not for life that has evolved in other climactic periods.

 

Humans, and all life currently on the Earth, has evolved for life in this climactic condition. If we enter a warm climactic period, it will be a disaster for much of life on Earth.

 

It won't be a total disaster by a long shot, but it will be quite bad. We don't know exactly why one species survives the transition and another fails. But even widely successful species can become extinct during these transitions.

 

If we enter a warm period, then we don't know how we will handle it. There are many species that we rely on (eg: crop staples). We don't know how these will respond to the event. But there is enough that we rely on that some will most definitely be negatively effected.

 

So we can't predict how bad it will be (the Doom Sayers say that it will be very bad), but we can be almost certain that there will be disruptions, and that this disruption will have negative effects for humanity.

 

I seriously doubt that we will become extinct, but there will very likely be a lot more wars, famines and general loss of quality of life. I think a worst case scenario would be the world ending up in a 3rd world state, but we will still exist and we will still have our societies mostly intact. However, I think the likely scenario will be a dramatic loss in quality of life as many people fleeing wars that do break out, or the results of shifts in weather patterns turns once fertile areas into deserts pus more pressure on countries less effected by the new state of affairs.

[scalbers]

Remember also that the CO2 we emit stays in the atmosphere/ocean system for many thousands of years. So the more we emit, the more we would really need to suck back out of the atmosphere by some new technology. It is less risky to act soon to cut emissions. CO2 levels right now are likely higher than has been seen for millions of years. That in my opinion is too much human impact.

 

In the big picture we have twin issues of warming in the atmosphere and acidification in the oceans.

[SkepticLance]

To Edtharan

 

Let me commend you again. There are certain people inhabiting the science forum who would be unable to debate, and disagree as we do without descending to insults and ad hom attacks. I find it pleasant to debate with someone who can rise above that. Thank you.

 

I do insist on my right to disagree. For example : take complexity. In ecology, the more complex a system is, the more stable it is. The same should apply to climate. If a system is highly complex, including many feed-back mechanisms, the net results should be (like in ecology) to increase the stability of the system.

 

On trends being linear. In fact, nothing in nature is ever linear. Everything fluctuates. However, we can approximate linearity for some things. For example : the warming over the past 30 years approximates linear. There are lots of small fluctuations in temperature over that period, but a regression line can be drawn through all the points on the graph that is damn near a perfect straight line.

 

In earlier times temperatures vary considerably. We have a long history of fluctuations, over a period of (say) 500 years, of temperatures rising and falling over about 1 Celsius. The peak of the Roman Empire was a warm time. The 'dark ages' occurred during a time of relative cool. 900AD to 1200 AD is often referred to as the Medieval Climate Optimum, and was a time of relative warmth. The period of 1350 to 1800 was the Little Ice Age and lived up to its name.

 

Over that time period, of course temperatures are not linear, and I never implied that. Even approximate linearity will be over shorter periods. Perhaps a few decades at most.

 

As you said, we cannot use that approximate linearity to predict future trends. However, neither can we predict accelerating warming. As I pointed out, if CO2 increase continues at the present rate, the rate of warming will reduce, since the relationship is an inverse exponent. Only if CO2 emissions increase very substantially, will warming increase beyond what it is to any great degree.

 

You suggested that, because the last warming began around 1750 to 1800 AD, it had to be related to the industrial revolution and CO2 release. That suggestion looks exceedingly unlikely when you look at actual rate of CO2 increase. Before WWII, carbon emissions were very minor indeed. And in the 19th century, they occurred at a rate of about 5% of the current level. Yet warming until WWII was 0.5C, and since only about 0.3 C in spite of carbon emissions accelerating 20 fold.

 

My belief is that a change in a vital natural parameter was the primary cause of cooling from 1200 to 1500 AD, and the return of that variable to 'normal' conditions drove the warming from 1800 to 1940 AD. We even know which parameter. It appears to be sunspot activity, which was very high during the Medieval Climate Optimum, and nearly zero during the Little Ice Age, and rising to massive again by 1940.

 

Though many will dispute with me, I believe that the only clear cut warming caused almost solely by human activity, largely unaffected by other significant factors, has been from 1976 to the present.

[iNow]

The challenge, Lance, with comparing climate today with climate all those centuries ago is that the inputs to the system are greatly different now. You concede that carbon dioxide has a huge impact on our climate. You admit that humans are releasing carbon dioxide at unprecedented rates, digging deposits from the ground and burning them into our air. You acknowledge that we know more about this process now than at any point in human history.

 

Yet... for some reason, you disagree with the conclusions of the experts, the people who have dedicated themselves to learning everything they can on this topic, themselves very honest people with a great degree of integrity.

 

I just don't get it, mate. What more do you need to accept the truth of the situation, and that the change is happening even faster than previously thought?

[SkepticLance]

To iNow

In any issue there is data, and there is interpretation.

I do not challenge data, unless I have good reason to believe it is faulty. Interpretation on the other hand ......

 

I see my role in these kinds of discussions as being the person who points out the degree of doubt and uncertainty. I may puncture a few people's fond beliefs, and make myself unpopular that way. But it is still healthy to have someone who challenges.

 

In global climate change, there is a chunk of good data, and certain obvious conclusions. And then there is interpretation, in which different people extend their speculations to different degrees. Some of the reasoning used is good, and solid. Some is weak and tenuous. And some is almost certainly quite wrong. One of the things that makes me a bit different is that I know perfectly well that beyond a certain point the conclusions are seriously uncertain.

 

By contrast, a lot of people regard global climate change modelling as an exact science. It is not. It is highly uncertain, and there will be a bunch of surprises in store over the next few decades. Some have already been experienced, but there will be more.

 

In fact, as I have pointed out before, there is quite a body of scientific literature, in reputable scientific journals, pointing out the possible sources of error in climate modelling, and hence in the accuracy of models conclusions. When I point these out, it is not well received. I suspect that some people regard the disaster interpretation of climate change almost as a religion.

[iNow]

Ermm... Those people whose "fond beliefs" you claim to puncture are the very experts to whom I referred. Nobody is talking about religious like beliefs, exact predictions, or disaster interpretations, so that's a pretty blatant red herring.

[SkepticLance]

iNow

 

Exactly right. People like Dr. George Hansen who firmly believes that sea levels around the world will rise 5 metres before the year 2100 AD. The evidence underpinning this is meagre to say the least. His logic is most shaky. People like Dr. Stephen Schneider, who admitted to an interviewer that he deliberately exaggerated his message. He considered that justified in order to alert people to the danger. Sorry, iNow. I prefer honesty, integrity, and sanity.

[iNow]

Another red herring (as if I and others don't "prefer honest, integrity, and sanity.") You've named two people, and yet choose to cast aside the work of all the other countless thousands publishing in the field.

 

 

I keep telling myself to ignore you. I don't know why I don't.

[SkepticLance]

iNow

 

As I tried to point out earlier, solid data is not something I sneer at. However, the vast bulk of these debates is not about data. It is about different ways the data is interpreted. The interpretation is highly variable and highly dependent on the social, emotional, and political bent of the person doing the interpretation.

 

As I have said before, all scientists are also human, and behave in ways that are normal for humans to behave. One normal behaviour is that of the reinforcement of the group. A well studied and pretty much ubiquitous behaviour. This is well recognised with religious and pseudoreligious groups.

 

This happens when a group of people get together who all agree on a subject. As they discuss the subject together, they reinforce each others views and strengthen those views on an emotional level till they move towards extremism. For example : the older feminists who got together and determined that 'all men are rapists.' I mention that example because I have been verbally attacked by some of these women and accused of being a rapist (falsely, I hasten to add) simply because I am male.

 

Another example is Muslims who discuss the 'threat' of Americans to their faith. Their mutual agreement reinforcing each other can lead to atrocities such as 9/11.

 

However, the principle applies equally well to believers in the disastrous outcomes of global warming. The more these groups get together and talk to each other, the more extreme their views become. This is totally normal human behaviour, but leads to ideas that are just plain exaggerated. As witness Hansen and his 5 metre sea level rise.

 

The 'proper' scientific approach, which by passes these all too human weaknesses, is to rely on the scientific method. This was originally written down by Sir Francis Bacon, and uses empirical (real world) testing as the yardstick by which our picture of reality is achieved. When we stray from this principle we do so at severe risk of spreading the bulldust.

 

A good example is super string theory. It is currently a form of science fiction. The reason why it is fiction (or speculation) is because there is no empirical testing to support the ideas. Super string theory will remain speculation until someone finds a suitable empirical test, at which stage it will become a more solid theory, or be disproven totally.

 

Much of modern global warming ideas have been developed by the same method used for super string theory. That is : moving away from the real world and into an internal world of models - both computer and mental. Until these things are fully tested by empirical means, they must be treated with suspicion.

 

If we rely on genuine data, we will see a warming of about 0.18 C per decade as a global average. Also an increase in CO2. We will see that this is unusual. We will conclude that human activity is causing warming, and we should do something about it. So far, that is sound science. However, it is the next step beyond that which we need to be sceptical of. We cannot predict the future, and we do not know that disaster is coming.

 

The simple truth is that the entire concept of global warming is full of doubt and uncertainty, and it is dishonest to deny that.

[scalbers]

It's fine to point out the uncertainty, however this shouldn't paralyze us from prudent and much needed action. This is the danger of being preoccupied with the skepticism. Is there any real doubt that the Earth's climate sensitivity to a doubling of CO2 beyond natural levels is about 3 deg C. And is there any real doubt about the other points I made in post #413?

 

And if the top of the envelope of uncertainty is the maybe 10-20% chance of Jim Hansen being right about Greenland, isn't that a reason for concern?

 

Also, the rate of warming may increase for a while due to the decreased albedo of the Arctic Ocean, and our cleaning up of cooling particulates in the atmosphere.

[swansont]

However, the principle applies equally well to believers in the disastrous outcomes of global warming. The more these groups get together and talk to each other, the more extreme their views become. This is totally normal human behaviour, but leads to ideas that are just plain exaggerated. As witness Hansen and his 5 metre sea level rise.

 

We went through this in posts ~230-240 of this thread, and you were unable to cite where Hansen actually made this as a prediction of some inevitable result.

 

 

If we rely on genuine data, we will see a warming of about 0.18 C per decade as a global average. Also an increase in CO2. We will see that this is unusual. We will conclude that human activity is causing warming, and we should do something about it. So far, that is sound science. However, it is the next step beyond that which we need to be sceptical of. We cannot predict the future, and we do not know that disaster is coming.

 

Bulldust, to use your terminology. If I place a block of ice in a room at 30ºC, I can predict that it will melt. If I know a few other things, I can even come up with an idea of how long that might take. Much like the above prediction of Hansen, it sets certain conditions, but it does predict the future, contingent on those conditions being met. It's what scientific models do.

 

The simple truth is that the entire concept of global warming is full of doubt and uncertainty, and it is dishonest to deny that.

 

It's unsubstantiated crap like this that tempts people to label you as a "denialist"

[SkepticLance]

The James Hansen quote was from :

 

http://environment.newscientist.com/article/mg19526141.600

 

He is quoted as saying :

 

"As an example, let us say that ice sheet melting adds 1 centimetre to sea level for the decade 2005 to 2015, and that this doubles each decade until the West Antarctic ice sheet is largely depleted. This would yield a rise in sea level of more than 5 metres by 2095.

 

Of course, I cannot prove that my choice of a 10-year doubling time is accurate but I'd bet $1000 to a doughnut that it provides a far better estimate of the ice sheet's contribution to sea level rise than a linear response. In my opinion, if the world warms by 2 °C to 3 °C, such massive sea level rise is inevitable, and a substantial fraction of the rise would occur within a century. Business-as-usual global warming would almost surely send the planet beyond a tipping point, guaranteeing a disastrous degree of sea level rise."

 

Swansont has implied before today that I indulge in lies or unsupported false assertions. I do not. As with the James Hansen statement above, what I say has a good basis. It does not prove I am always right, of course, since my sources can be wrong. However, if I am wrong, it is innocently so. My information is drawn from what should be good sources.

 

However, statements such as the one quoted above, must be challenged. When people come out with catastrophist bulldust like that, with no good scientific basis, it is time for true sceptics to point out that this is speculation.

 

To scalbers

 

The points you have just made are perfectly valid. I have always supported reasonable action to combat global warming. However, we must decide what is reasonable.

 

Suggestions for what we should do range from dropping a trillion tonnes of powdered lime into the ocean, to dumping iron filings in the ocean, to orbiting thousands of mirrors to reflect heat away, to laying thousands of square kilometres of white cloth over the land to reflect away heat, to banning private cars, to building 10 million wind turbines etc etc.

 

Rather obviously, some of those suggestions are sheer stupidity. I advocate careful, well managed, and well researched action. Some things can be done now, and some will require more research. I suggest a bit of good sense in such decisions, and an avoidance of crackpots. I also see no point setting up 'remedial' action that forces significant drops in standard of living or removes our precious liberty.

[Mr Skeptic]

According to a New Scientist article, it seems there is a weekly pattern to the weather that is very likely due to our weekly activities. The latest article is about the effect in Europe, but it seems that there is a stronger effect in the US and Asia.

[swansont]

The James Hansen quote was from :

 

http://environment.newscientist.com/article/mg19526141.600

 

He is quoted as saying :

 

"As an example, let us say that ice sheet melting adds 1 centimetre to sea level for the decade 2005 to 2015, and that this doubles each decade until the West Antarctic ice sheet is largely depleted. This would yield a rise in sea level of more than 5 metres by 2095.

 

Of course, I cannot prove that my choice of a 10-year doubling time is accurate but I'd bet $1000 to a doughnut that it provides a far better estimate of the ice sheet's contribution to sea level rise than a linear response. In my opinion, if the world warms by 2 °C to 3 °C, such massive sea level rise is inevitable, and a substantial fraction of the rise would occur within a century. Business-as-usual global warming would almost surely send the planet beyond a tipping point, guaranteeing a disastrous degree of sea level rise."

 

Swansont has implied before today that I indulge in lies or unsupported false assertions. I do not. As with the James Hansen statement above, what I say has a good basis. It does not prove I am always right, of course, since my sources can be wrong. However, if I am wrong, it is innocently so. My information is drawn from what should be good sources.

 

However, statements such as the one quoted above, must be challenged. When people come out with catastrophist bulldust like that, with no good scientific basis, it is time for true sceptics to point out that this is speculation.

 

 

When you say or imply that Hansen predicted that there will be a 5-meter rise, in order to impugn climate models, yes I will say you are misrepresenting things, because you are.

 

Is the first statement you quoted from Hansen wrong?