Global Warming debate

[anthony263]

I was led to believe that Britain was in a cycle of Ice Ages and that Britain is currently in a warm period in-between two very cold periods. Cheshire, where I live, was under a very great depth of ice in recent geological times.

There is much mention of human intervention in climate change methodology, but there are natural activities such as volcanic activity, that can cause devastating events with regard to altering regional temperatures. There were some area climatic changes when the Mount St Helens incident occurred, but this will be as nothing if a supervolcano were to erupt. The last such occurrence was 74,000 years ago at Toba in the Sumatran region of the Pacific Ocean which created a global catastrophe. Much media interest has featured upon the supervolcano under Yellowstone Park that is said to be on an eruption cycle of 600,000 years. It is said that as the last such eruption occurred 640,000 years ago, the next occurrence is somewhat overdue.

All it needs is a similar repeat of the events caused by the entering of a large asteroid into the atmosphere and making landfall at Chicxulub at the tip of the Yucatan Peninsula in the central American area in the region of the Gulf of Mexico that led to the demise of the Dinosaurs, to make climate change discussion somewhat meaningless.

Watched a documentary on the yellowstone supervolcano last night. Seems some are predicting a possible eruption in 2012 . The evidence is that the ground is rising and there has been a lot of siesmic activity

 

[90019]

Errr - yes - volcanoes, solar activity, changes in earth's orbit, etc, etc. What's happened is that humans have added another factor, one that causes the climate to be warmer THAN IT WOULD OTHERWISE HAVE BEEN had humans not existed.

And your scientific evidence over a geological timescale for this is...?

Then why is every continent eating better than it ever has?

Even if this is true, more food available to the populations is countered by the ever increasing popolations, which means that an increase in food doesn't necessarily mean people are eating better. It can also be that certain parts of a population are eating much better whilst the majority are doing the same or worse than they were previously.

I should point out that these clever renewable fuels nearly made the national grid go offline on 14th September due to excessive wind shorting the system.

Renewables aren't perfect, they have their flaws, but so do all power sources. However they are very useful to supplement others when extra is needed, but we cannot rely on them solely for our energy needs.
Hopefully in the next few decades, as progress is made on nuclear fusion, we can greatly reduce our reliability on the finite supply of fossil fuels and move towards cleaner, more reliable and less polluting power production. Until fusion becomes viable, fission is the way forward in my opinion, supplemented by renewables.

 

[exile]

And your scientific evidence over a geological timescale for this is...?

I don't know what you mean. CO2 has definitely increased over the last 200 years.

 

[90019]

CO2 has definitely increased over the last 200 years.

CO2 may have increased from yesterday to today, but I can't use that as evidence to say it's been increasing for the past millenium.

 

[exile]

CO2 may have increased from yesterday to today, but I can't use that as evidence to say it's been increasing for the past millenium.

http://en.wikipedia.org/wiki/File:Carbon_Dioxide_400kyr.png

 

[table38]

Where do I start? CO2 is of course a greenhouse gas, and a very effective one. Most of the atmosphere is oxygen and nitrogen, neither of which are greenhouse gases. So, your 1st argument has no validity. If I eat a pound of potatoes in which there is a gram of cyanide, does that mean the potatoes will kill me?

But we aren't considering a finite amount of something here, we are considering a finite change.

Some CO2 is beneficial. I don't think there is a beneficial amount of cyanide. What you appear to be arguing is that 0.83 of a gram of cyanide wouldn't kill you, but 1 gram would.

Water vapour is of course a greenhouse gas, and contributes about twice as much as CO2 to global warming. I've got news for you - that is also increasing, as warmer air can absorb more water vapour.

Funny that all these Hydrogen cars are billed as being green because they only emit water vapour then!

http://en.wikipedia.org/wiki/Greenhouse_gas

So I guess you also believe that Bob Holness played saxaphone on Baker Street I think you need to understand how Wikipedia works.

 

[Stewart]

Where's your source for that? In any case, it is an accepted fact amongst scientists that the lack of food (mainly to do with the poor energy transfers between trophic levels) will become a limiting factor for population.

Here is a graph showing how nutrition has improved for developed and undeveloped countries

http://wattsupwiththat.com/2010/09/08/i-am-so-tired-of-malthus/
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http://en.wikipedia.org/wiki/Climate_change

"The scientific consensus on climate change is "that climate is changing and that these changes are in large part caused by human activities,"[38] and it "is largely irreversible"

So, it's still very much the majority opinion that human activity is changing the climate.

And it was very much majority opinion that the sun was orbiting the earth, and that Greece joining the Euro was a good thing.

 

[exile]

But we aren't considering a finite amount of something here, we are considering a finite change.

Some CO2 is beneficial. I don't think there is a beneficial amount of cyanide. What you appear to be arguing is that 0.83 of a gram of cyanide wouldn't kill you, but 1 gram would.

There are many things of which a small amount is beneficial and a large amount lethal - vitamins, sugar, etc

Funny that all these Hydrogen cars are billed as being green because they only emit water vapour then!

So, now you think water vapour isn't a greenhouse gas?

So I guess you also believe that Bob Holness played saxaphone on Baker Street I think you need to understand how Wikipedia works.

Ad hominem fallacy.

 

[ralphchadkirk]

Water vapour may be a greenhouse gas, but it doesn't just remain in the atmosphere. It has an atmospheric lifetime of approximately a week before it condenses and falls as rain or snow.

 

[exile]

Water vapour may be a greenhouse gas, but it doesn't just remain in the atmosphere. It has an atmospheric lifetime of approximately a week before it condenses and falls as rain or snow.

However, if the temperature of the atmosphere increases, it can hold more water vapour.

http://www.agu.org/pubs/crossref/2011/2010JD015065.shtml

 

[Stewart]

However, if the temperature of the atmosphere increases, it can hold more water vapour.

http://www.agu.org/pubs/crossref/2011/2010JD015065.shtml

You then get more clouds, which cool the earth. So we have a nice balance

 

[Snapper]

What amazes me is that some otherwise sensible people are so easily led by the dodgy science and half-truths that are wheeled out to deny that man made global warming is real.

 

[Yew]

How does man made global warming explain the average increase in temperature across all the planets in the solar system then?

 

[exile]

According to this, water vapour in the stratosphere has declined recently:-

http://www.guardian.co.uk/environment/2010/jan/29/water-vapour-climate-change

There's a suggestion that this may be a negative feedback counteracting global warming. It shows how difficult climate modelling and prediction is. Variables exist that don't get fed into the models.

However, fundamentally, the situation is that over hundreds of millions of years the amount of carbon in the atmosphere has being decreasing, as it's been absorbed into living beings and then stored in the earth's crust as carbon compounds including fossil fuels.

Human beings are now busy returning much of the carbon to the atmosphere, in a very short space of time. Now though some people on this thread don't believe carbon dioxide can have any significant greenhouse effect based on the argument that it's only a small proportion of the total atmosphere, it actually is a greenhouse gas and a very powerful one. I don't know of any reputable scientist who is saying it isn't.

Unless there are enough negative feedback mechanisms to counteract the increasing amounts of CO2, then the effect is going to be that the earth will be warmer than it otherwise would have been. That's all!

The arguments are basically around how much of the warming trend is due to human activity, and what, if anything, we need to do about the situation - and what effect the warming will actually have on sea levels, weather and so on.
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How does man made global warming explain the average increase in temperature across all the planets in the solar system then?

Ummm - what average increase in temperature?

 

[Hydro]

What amazes me is that some otherwise sensible people are so easily led by the dodgy science and half-truths that are wheeled out to deny that man made global warming is real.

What amazes me is that people are so easily led by dodgy science and half truths on both sides that they can hold black and white, right and wrong views of the subject in hand, whereas in reality the waters are a lot murkier. Anyone with half a braincell can see that a lot more work needs to be done to prove half a point either way.

You cannot effectively denigrate peoples sensibility for holding a view opposite to yours, especially when it's not actually been proved conclusively either way.

 

[exile]

However, the basic physics demonstrating that CO2 is a greenhouse gas is beyond serious dispute (except in this thread)

And once you accept that then if you want to prove human activity is not contributing to global warming you have a lot of work to do. You have to
find some other mechanism that's directly counteracting the greenhouse effect from the CO2.

 

[90019]

it actually is a greenhouse gas and a very powerful one.

It is one of, if not the, least powerful greenhouse gas, in terms of warming potential compared to other greenhouse gases, Carbon Dioxide is pretty pathetic.

If you want to focus on the powerful ones, you need to look at Methane, Nitrous Oxide and gases like CFCs.

 

[Stewart]

However, the basic physics demonstrating that CO2 is a greenhouse gas is beyond serious dispute (except in this thread)

And once you accept that then if you want to prove human activity is not contributing to global warming you have a lot of work to do. You have to
find some other mechanism that's directly counteracting the greenhouse effect from the CO2.

CO2 is a greenhouse gas but the earth's climate is vastly more complex than climate modellers like to make out. Dr Roy Spencer's theory of a self-regulating earth via clouds (they cool things down when it's hot, warm things up when it's cold, and act as shields to incoming solar radiation) looks very plausible when you consider how stable the earth's climate is.

 

[Snapper]

Dr Roy Spencer's theory of a self-regulating earth via clouds (they cool things down when it's hot, warm things up when it's cold, and act as shields to incoming solar radiation) looks very plausible when you consider how stable the earth's climate is.

The only problem is that it isn't plausible - as the furore over Spencer and Braswell's recent paper has demonstrated:

http://www.yaleclimatemediaforum.org/2011/09/the-science-behind-the-spencer-braswell-paper/
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You cannot effectively denigrate peoples sensibility for holding a view opposite to yours, especially when it's not actually been proved conclusively either way.

Actually you can. You can also denigrate people for being willing to bet the future of the planet unless something is proved 'conclusively' rather than understanding that by the time that happens it's actually far too late to do anything about it.

 

[Snapper]

The truth is uncomfortable sometimes. We only have one planet so we'd better look after it. Sticking one's head in the sand over the realities and consequences of global warming really is foolish.

 

[Hydro]

We only have one planet so we'd better look after it.

Which is sound advice, and perfectly possible without tying it up in "with us or against us" mentalities. Certainly possible without practically saying "If you question it you're stupid".

 

[ChrisCooper]

The way I see it, does it really matter? Fossil Fuels are running out, so we cannot sustain the current use of them forever, regardless of the effects the carbon produced by burning them is having. The other issue when it comes to climate change is in terms of deforestation and change of land use. I don't think there has been much real study on the long term impact this will have on the environment on it's own, regardless of the carbon issue. I don't doubt at all climate change is happening, just look at the weather the UK has had. Global Warming works as an overall term, because there is a global temperature increase being detected, but fails in the publics eye because it doesn't always describe local effects. The UK particularly seems to be going the other way, something that has actually been predicted from a long time. The idea that global warming should lead to hot dry summers and warm wet winters is not really backed by the science, but tends to be picked up by the media as it sounds exciting (the idea that the UK is gradually moving towards the Mediterranean).

 

[Stewart]

The only problem is that it isn't plausible - as the furore over Spencer and Braswell's recent paper has demonstrated:

http://www.yaleclimatemediaforum.org/2011/0/the-science-behind-the-spencer-braswell-paper/
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Why haven't we had any global warming since 1998 if positive feedbacks dominate?
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The truth is uncomfortable sometimes. We only have one planet so we'd better look after it. Sticking one's head in the sand over the realities and consequences of global warming really is foolish.

Global warming takes attention and investment away from real problems.
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I don't doubt at all climate change is happening, just look at the weather the UK has had.

What sort of weather in the UK supports the global warming theory?

 

[90019]

Why haven't we had any global warming since 1998 if positive feedbacks dominate?

You can't use a time period that short for evidence of a phenomenon like climate change that happens on a geological timescale.

 

[Snapper]

Global warming takes attention and investment away from real problems.

Global warming is a real problem!


http://www.giss.nasa.gov/research/news/20110113/
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Why haven't we had any global warming since 1998 if positive feedbacks dominate?

Who says we haven't?

 

[90019]

Global warming is a real problem!


http://www.giss.nasa.gov/research/news/20110113/?

Cimate change is occuring. Whether natural or man made, there isn't yet enough evidence to say.

 

[Snapper]

Cimate change is occuring. Whether natural or man made, there isn't yet enough evidence to say.

Untrue. The climate is changing - it's warming up!

As for their not being enough evidence - this is also untrue. There's plenty of evidence to support the theory that global warming is man made. What there isn't is the ability to prove that conclusively and remove absolutely all doubt.

However, the fact that MMGW can't be proved beyond all doubt shouldn't mean that we ignore the evidence and refuse to act - that would be foolish in the extreme. We risk far too much.

 

[Stewart]

Cimate change is occuring. Whether natural or man made, there isn't yet enough evidence to say.

Climate change is always occurring
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Untrue. The climate is changing - it's warming up!

As for their not being enough evidence - this is also untrue. There's plenty of evidence to support the theory that global warming is man made. What there isn't is the ability to prove that conclusively and remove absolutely all doubt.

However, the fact that MMGW can't be proved beyond all doubt shouldn't mean that we ignore the evidence and refuse to act - that would be foolish in the extreme. We risk far too much.

We have had no warming since 1998 despite plant food emissions continuing to increase.

If you look back through history, you tend to find warmer periods coincide with human advances, and cold periods with times of difficulty. So even if global warming was going on, it would be beneficial. A new ice age would be much much worse.

 

[Snapper]

We have had no warming since 1998 despite plant food emissions continuing to increase..

That is simply untrue. You offer no evidence to back that statement up and you ignore the evidence from the NASA link I posted earlier which makes it abundantly clear that we have had plenty of warmer years since 1998.

"NASA's announcement this year — that 2010 ties 2005 as the warmest year in the 131-year instrumental record — made headlines. "


http://www.giss.nasa.gov/research/news/20110113/

 

[exile]

Climate change is always occurring
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We have had no warming since 1998 despite plant food emissions continuing to increase.

Not true. 1998 was indeed the warmest year on record but the longer term trend is still upward

http://en.wikipedia.org/wiki/File:Satellite_Temperatures.png

Even if true it wouldn't demonstrate that CO2 isn't a greenhouse gas and that it doesn't contribute to global warming.

If you look back through history, you tend to find warmer periods coincide with human advances, and cold periods with times of difficulty. So even if global warming was going on, it would be beneficial. A new ice age would be much much worse.

Now you're saying human-induce global warming DOES occur but it's a good thing. Maybe it is if you don't live on the coast!
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It is one of, if not the, least powerful greenhouse gas, in terms of warming potential compared to other greenhouse gases, Carbon Dioxide is pretty pathetic.

If you want to focus on the powerful ones, you need to look at Methane, Nitrous Oxide and gases like CFCs.

Not true - although those gases are more powerful greenhouse gases per kg, when you take into account the actual amount of gases in the atmosphere, CO2 is much more significant as a greenhouse gas.

http://en.wikipedia.org/wiki/File:Satellite_Temperatures.png
(this does have a reference!)

Those gases are also increasing and largely due to human activity.