question about climate change and the Bible

[tidalforce]

Are we all done with talk of proxies and hockey sticks? Good.

The fact is the earth is warming now when all logic says that it should be cooling, and there is no natural explanation that climate sceptics can provide of what is driving the current warming trend. Sure the Milankovitch and solar cycles have been important in driving climate change in the recent and distant past, but there is no climate theory that explains the current and observed changes in climate that does not hinge on CO2 driving the temperature change.

[DannyM]

Are we all done with talk of proxies and hockey sticks? Good.

The fact is the earth is warming now when all logic says that it should be cooling, and there is no natural explanation that climate sceptics can provide of what is driving the current warming trend. Sure the Milankovitch and solar cycles have been important in driving climate change in the recent and distant past, but there is no climate theory that explains the current and observed changes in climate that does not hinge on CO2 driving the temperature change.

The fact is we are currently in the midst of a small cooling period amongst an overall warming period; this overall warming period being no higher than previous warming periods. Period!

Also, CO2 lags temperature. not the reverse. Your comment there is just plain WRONG.

Oh, and your choice of phrase is a complete Red Herring..."Climate sceptics..."? How can I deny the climate?

Think again.

[tidalforce]

Are we all done with talk of proxies and hockey sticks? Good.

The fact is the earth is warming now when all logic says that it should be cooling, and there is no natural explanation that climate sceptics can provide of what is driving the current warming trend. Sure the Milankovitch and solar cycles have been important in driving climate change in the recent and distant past, but there is no climate theory that explains the current and observed changes in climate that does not hinge on CO2 driving the temperature change.

The fact is we are currently in the midst of a small cooling period amongst an overall warming period; this overall warming period being no higher than previous warming periods. Period!

Also, CO2 lags temperature. not the reverse. Your comment there is just plain WRONG.

We were in the midst of a cooling trend (as shown by various proxies) from the mediaeval warm period and earlier. The overall climate has, as far as proxies can be relied upon, been steady to dropping for the past 400 years or so. The jury is out on whether the current warming is of a greater, lesser or equal magnitude to the MWP (let's say, for argument's sake, that the MWP was warmer than it is now) but, and here's the crucial bit, no known natural causes or cycles can be implicated in the current warming trend.

Your statement on CO2 lag would be more accurate if you had worded it "ice-core proxies show that, in previous glacial termination events (on a ~100,000 year cycle) temperature rises preceded CO2 rises". This is distinct from the separate observation (observed via direct measurements, not proxies) that global temperatures and CO2 concentrations are, right now, rising together.

[DannyM]

We were in the midst of a cooling trend (as shown by various proxies) from the mediaeval warm period and earlier. The overall climate has, as far as proxies can be relied upon, been steady to dropping for the past 400 years or so. The jury is out on whether the current warming is of a greater, lesser or equal magnitude to the MWP (let's say, for argument's sake, that the MWP was warmer than it is now) but, and here's the crucial bit, no known natural causes or cycles can be implicated in the current warming trend.

Your statement on CO2 lag would be more accurate if you had worded it "ice-core proxies show that, in previous glacial termination events (on a ~100,000 year cycle) temperature rises preceded CO2 rises". This is distinct from the separate observation (observed via direct measurements, not proxies) that global temperatures and CO2 concentrations are, right now, rising together.

Okay, so we're not too far apart here. I would only add that as far as I can see the jury is most certainly in on the MWP being (around 0.5-1.0C) warmer than the CWP. You are right to correct me about my wording with regards C02 lagging temperatures; it is generally accepted that CO2 is lagging temperature in Antarctic graphs. But the reality is that these graphs are still widely used as an argument for the AGW hypothesis. You need to show temperature does lag C02 if there is going to be any chance of you having a case. And by how long does this occur?

[DannyM]

The jury is out on whether the current warming is of a greater, lesser or equal magnitude to the MWP (let's say, for argument's sake, that the MWP was warmer than it is now) but, and here's the crucial bit, [i]no known natural causes or cycles can be implicated in the current warming trend[/i].

Here's another Red Herring. Can you explain to me how this "crucial" piece of information helps your case?

[tidalforce]

The jury is out on whether the current warming is of a greater, lesser or equal magnitude to the MWP (let's say, for argument's sake, that the MWP was warmer than it is now) but, and here's the crucial bit, ]no known natural causes or cycles can be implicated in the current warming trend.

Here's another Red Herring. Can you explain to me how this "crucial" piece of information helps your case?

Because we know that CO2 et al are greenhouse gases, and we know that both greenhouse gas concentrations and global average temperatures have increased over the past century or so.

It's all well-and-good pointing out, for example, past eras where CO2 has not been the initiating factor in warming events, but that says nothing about the current situation.

[DannyM]

Because we know that CO2 et al are greenhouse gases, and we know that both greenhouse gas concentrations and global average temperatures have increased over the past century or so.

Again, this is a non-answer. We know that CO2 is a minor greenhouse gas. The above statement is just an acknowledgement of two facts. Actually, I can argue that we have been in a warming period for over a thousand years. You are giving yourself a starting point of 100 years ago. Why is that? I can give a starting point of pre-MWP and factor in the LIA as a cooling period amongst an overall warming period. Which of course would put today's warming in complete perspective. But, of course, you start at 100 years ago and give yourself a 'case.' But only by bypassing the rest of history. It would be clever if it were not so transparent.

It's all well-and-good pointing out, for example, past eras where CO2 has not been the initiating factor in warming events, but that says nothing about the current situation.

You're wrong. Past trends can help us keep trends like the CWP in perspective. The idea of placing CO2 in a central role for driving temperatures because “we cannot explain the big changes in temperature with anything other than CO2″ is just bogus. It is a false argument. It's not even a process of elimination. It's a monumental assumption based on...well...no prior evidence.

[tidalforce]

Because we know that CO2 et al are greenhouse gases, and we know that both greenhouse gas concentrations and global average temperatures have increased over the past century or so.

Again, this is a non-answer. We know that CO2 is a minor greenhouse gas. The above statement is just an acknowledgement of two facts. Actually, I can argue that we have been in a warming period for over a thousand years. You are giving yourself a starting point of 100 years ago. Why is that? I can give a starting point of pre-MWP and factor in the LIA as a cooling period amongst an overall warming period. Which of course would put today's warming in complete perspective. But, of course, you start at 100 years ago and give yourself a 'case.' But only by bypassing the rest of history. It would be clever if it were not so transparent.

I completely understand your point about where to start plotting trends from; there are any number of periods you can select over the past millions of years that will either result in the appearance of the 21st century being in the midst of an overall warming or cooling trend. I chose ~100 years as that is how far back instrumented CO2 and temperature records go, so sorry if it made it look like I was trying to dismiss the rest of history out of hand.

The idea of placing CO2 in a central role for driving temperatures because “we cannot explain the big changes in temperature with anything other than CO2″ is just bogus. It is a false argument. It's not even a process of elimination. It's a monumental assumption based on...well...no prior evidence.

I don't see it as a monumental assumption. To put it as simply as possible - the warming measured over the last century or so would not have happened absent some forcing:

1. There is no reason to think that increased CO2 concentrations will not lead to temperature changes of some magnitude - and instruments shows that CO2 concentrations are rising
   1. The CO2 rise may be mainly anthropogenic
   2. The CO2 rise may be mainly natural
2. If not attributable to CO2 then the warming must be attributable to some other cause
   1. That other cause may be solar/orbital cycles
   2. Out-gassing of greenhouse gases other than CO2
   3. Some other known cause
   4. An as-yet-unknown cause
   5. A combination of some or all of the above

Would it be a fair of me to say that we both agree with the statement that any global temperature changes must be attributable to some cause, though our views differ on what the likely cause of recent warming is?

[DannyM]

I completely understand your point about where to start plotting trends from; there are any number of periods you can select over the past millions of years that will either result in the appearance of the 21st century being in the midst of an overall warming or cooling trend. I chose ~100 years as that is how far back instrumented CO2 and temperature records go, so sorry if it made it look like I was trying to dismiss the rest of history out of hand.

I accept that was not your motive. But I seriously believe it is the motive of others.

I don't see it as a monumental assumption. To put it as simply as possible - the warming measured over the last century or so would not have happened absent some forcing:

1. There is no reason to think that increased CO2 concentrations will not lead to temperature changes of some magnitude - and instruments shows that CO2 concentrations are rising
   1. The CO2 rise may be mainly anthropogenic
   2. The CO2 rise may be mainly natural
2. If not attributable to CO2 then the warming must be attributable to some other cause
   1. That other cause may be solar/orbital cycles
   2. Out-gassing of greenhouse gases other than CO2
   3. Some other known cause
   4. An as-yet-unknown cause
   5. A combination of some or all of the above

Would it be a fair of me to say that we both agree with the statement that any global temperature changes must be attributable to some cause, though our views differ on what the likely cause of recent warming is?

Absolutely agreed.

[DannyM]

tidalforce,

You wrote:

"1.There is no reason to think that increased CO2 concentrations will not lead to temperature changes of some magnitude - and instruments shows that CO2 concentrations are rising

a.The CO2 rise may be mainly anthropogenic
b.The CO2 rise may be mainly natural"

This is the only part of your last post that I would contend with. I think there is every reason to think that CO2 emissions will not lead to temperature rises of any magnitude. Abundant evidence of CO2 lagging temperatures, and not driving temperatures, would be reason enough. Wouldn't it?

[jlay]

We know that CO2 is a minor greenhouse gas.

We also need to make clear that CO2 is not a polutant. It is a natural part of our atmosphere.

Great lenghts have already been taken to reduce the release of CO2 and actual harmful gasses into the atmosphere by man. Very expensive methods have been implemented in a number of areas including automotive emissions, and coal fired plants. Both to reduce CO2, SO2 and NOx emisions. In fact just in my area in the Tennessee Valley, billions have been spent on scrubbers for coal fired plants. Ultra Low sulfur diesel is another initiative that has been implented in the US, Cananda and Europe. This is reducing billions of particulates from the atmosphere.

In fact the latest emission requirements in the US and Europe are putting quite a burden on the auto industry.

http://www.oakridger.com/localnews/x177 ... n-December
This steam plant is on my old family farm.

[tidalforce]

I think there is every reason to think that CO2 emissions will not lead to temperature rises of any magnitude. Abundant evidence of CO2 lagging temperatures, and not driving temperatures, would be reason enough. Wouldn't it?

I think it's important to separate driving temperature change from triggering temperature change. The CO2 lag seen at the start of interglacial periods shows - pretty definitively - that CO2 did not trigger the warming; some event took place which caused temperatures to rise, which in turn led to CO2 out-gassing from oceans & glaciers.

That CO2 can contribute to some extent to global temperature changes is pretty obvious just in terms of the physics of how it interacts with infra-red radiation. In sufficient quantities CO2 theoretically ought to be able to warm the planet all by itself. What that sufficient quantity would be, or how significant a solely CO2-driven warming event could be are, of course, separate questions.

[tidalforce]

Great lenghts have already been taken to reduce the release of CO2 and actual harmful gasses into the atmosphere by man. Very expensive methods have been implemented in a number of areas including automotive emissions, and coal fired plants. Both to reduce CO2, SO2 and NOx emisions. In fact just in my area in the Tennessee Valley, billions have been spent on scrubbers for coal fired plants. Ultra Low sulfur diesel is another initiative that has been implented in the US, Cananda and Europe. This is reducing billions of particulates from the atmosphere.

This is a very important point. If current levels of CO2 production are enough to drive more than negligible warming, then those billions have been well spent. If, however, anthropogenic greenhouse gases could only ever cause a small disruption in climate....