Has the IPCC underestimated GW?

Projection: In 1995, IPCC projected "little change in the extent of the Greenland and Antarctic ice sheets... over the next 50-100 years." In 2007 IPCC embraced a drastic revision: "New data... show[s] that losses from the ice sheets of Greenland and Antarctica have very likely contributed to sea level rise over 1993 to 2003."

Over the period 1992 to 2010 a mean annual GrIS of 12.9 Gt/yr was observed.

Tim the plumber wrote:If there is any evidence that the IPCC figures are indeed on the low side please tell me how this can be given the lack of warming since they came out in 1998.[/color]

IBdaMann wrote:

Tim the plumber wrote:If there is any evidence that the IPCC figures are indeed on the low side please tell me how this can be given the lack of warming since they came out in 1998.[/color]

This is a question better suited for the Global Warming believers who care what the IPCC preaches.

I don't even know what "climate" is supposed to be, much less how it's supposed to be changing, what its units of measure are or whether that's even important in any of the IPCC sermons.

Tim the plumber wrote:
[color=blue]Climate is the sum of weather.

Tim the plumber wrote: In order to describe it you need to make clear what period you are looking at and what aspect of you want to deal with.

Tim the plumber wrote: Averages are very often misleading as they will fail to describe the often most important parts of the climate of a region or even day.

Tim the plumber wrote: It is reasonable to describe over all climatic conditions as being mild on global scale today as we are in the middle of an interglacial period.

Tim the plumber wrote: It is reasonable to talk about how many degrees we are warmer than the depths of the ice age.

Tim the plumber wrote: Measuring climatic temperatures to the hundreths of a degree is silly.

Tim the plumber wrote: This is because temperature is very difficult to measure to that level of accuracy at the best of time.

Tim the plumber wrote: Doing it outside and over large areas is just nuts. The figures for weather stations are often accurate to + or - 2 degrees c.

Tim the plumber wrote:If you are going to debate on a climate-debate forum it is sort of necessary to accept that the word can have meaning.

Tim the plumber wrote: You can say that the average temperature of the surface of the earth is "x".

Tim the plumber wrote: You can say that this is higher than the depths of the ice ages. You can also say this is lower than most of the history of the planet. Both are right.

Tim the plumber wrote: If you want to go into finer and finer detail untill you say that outside at the moment the climate here is fine and I am about to go and mow the lawn the that is also OK but it's a bit of a misuse of the world climate.

Tim the plumber wrote: My point, and I think yours, is that you can desacribe the climate in Cuba as hot and sunny in a very nice way. And as an average that's fine. But it is important to understand that there are hurricanes that will come across yearly and if you are building a house there it is these events which you should build against not the nice weather.

trafn wrote:
So far, these massive amounts of CO2 would only be responsible for minor fluctuations in global temperatures, and even that might be questionable as many other factors still contribute to these minor fluctuations

There are those who argue that this is all down to human release of CO2. That is silly. If the changes in CO2 levels due to human activity pre-1815 had the slightest effect on the world's climate then the comparitively massive amounts of CO2 we now pump out would be drastically changing the world's temperature.

climate scientist wrote:

There are those who argue that this is all down to human release of CO2. That is silly. If the changes in CO2 levels due to human activity pre-1815 had the slightest effect on the world's climate then the comparitively massive amounts of CO2 we now pump out would be drastically changing the world's temperature.

Actually, there has been no pause in sea ice melt, glacial melt, ice sheet melt, or ocean temperature increases. Water has a much higher heat capacity than air, and it is likely that the 'pause' in surface atmospheric temperatures is due to increased ocean uptake of heat:

http://www.nature.com/news/indian-ocean-may-be-key-to-global-warming-hiatus-1.17505

Since the ocean has a much higher heat capacity than the atmosphere, a lot more energy is required to raise its temperature. Therefore, the vast amount of CO2 that we 'pump out' is drastically changing the world's temperature.

But that scenario would cause vastly increased convective storm activity, which we have not seen. You are describing warm water under cold air.

climate scientist wrote:

But that scenario would cause vastly increased convective storm activity, which we have not seen. You are describing warm water under cold air.

Yes, on average the surface ocean is warmer than the atmosphere at the surface (although it depends on where you are, and what time of year). The mean surface atmospheric temperature is ~14-15 degrees C, whereas the mean surface ocean temperature is about 17 degrees C. The planet has had a slighter warmer surface ocean for a long time. Some of the heat uptake by the ocean is transported to the mid and lower ocean, where it does not have contact with the atmosphere. So this is why we have not seen a great change in storm activity, although storm activity is predicted to increase with future climate change. I guess that my point is that a 0.1 deg C raise in ocean temperature is a more drastic change in a way, than a 0.1 deg C raise in atmospheric temperature, because so much more energy is required to change the ocean's temperature than the atmosphere's temperature.

trafn wrote:
@Into the Night - instead of vastly increased convective storm activity, would you admit to there being mild or moderately increased convective storm activity?

trafn wrote:
Are you saying we're having the same or even possibly milder tornadoes and hurricanes now than in prior decades or centuries?

Warm water rises, just like warm air rises. Any warmer water will appear at the surface and make contact with the colder air (assuming your model) and vastly increased convective activity.

trafn wrote:
@Tim the plumber - good going, but beware. IBdaMann's thing is semantics (he's the definition guy).

As to your statement that ...the comparitively massive amounts of CO2 we now pump out would be drastically changing the world's temperature. As drastically as Trafn's dreams of Venus II. Since this is clearly not happening... I would disagree.

So far, these massive amounts of CO2 would only be responsible for minor fluctuations in global temperatures, and even that might be questionable as many other factors still contribute to these minor fluctuations (i.e. - fluctuations measured in factors of "0.xxx"). CO2 is, however, a powerful primer for pending events in our near future like nithane, and it will be events like nithane which will kickstart our planet down the road to true GW (i.e. - fluctuations measured in 10's or 100's of degrees).

Anyways, keep him on the ropes and your guard up. In the meantime, I think you and I are addressing my above comment in another thread where you're going to give me feedback on my text.

trafn wrote:
@IBdaMarxistMann - then for your Marxist satisfaction, I suggest you file my statement under predictions.

I'm sure you can find plenty of room for it in that empty filing cabinet where you had once hoped to store all your falsifiable models.

Tim the plumber wrote:
Past history is a better guide than a currently fashionable but utterly unsupported hypothesis. [/color]

Given that the predictions of the IPCC were that a rise in CO2 would result in a rise in temperature and the CO2 has risen even more sharply than they predicted without any rise in temperature

climate scientist wrote:
This is not true. Atmospheric temperature has risen as predicted by the IPCC:

How did you come by this divine knowledge? Was it a "climate" miracle?

climate scientist wrote:

Given that the predictions of the IPCC were that a rise in CO2 would result in a rise in temperature and the CO2 has risen even more sharply than they predicted without any rise in temperature

This is not true. Atmospheric temperature has risen as predicted by the IPCC:

"For the next two decades, a warming of about 0.2°C per decade is projected for a range of SRES emission scenarios. "

From AR4 report (2007)

Global temperature rise will likely be at least 0.2 deg C higher in 2017 than in 2007. The fact that there is no global warming is a myth:

http://www.skepticalscience.com/global-warming-stopped-in-1998-intermediate.htm

I'm not sure why you think that atmospheric CO2 has risen faster than the IPCC predicted? Do you have any evidence to back up this statement. Atmospheric CO2 has risen as it is expected to, given the fossil fuel emissions of the last decade.

Perhaps you are confused by articles, such as the one below, which states that CO2 emissions have risen faster than expected (largely due to a surge of growth in Asia):

http://www.telegraph.co.uk/news/uknews/1553508/CO2-rising-three-times-faster-than-expected.html

trafn wrote:
@Tim the plumber - yes, historical CO2 levels are believed to have been drastically higher than they are today. However, they got that way over millions of years which is consistent with natural causes, not in a few decades as we're seeing now which is consistent with AGW.

As to falsifiable models, they are like any good tool of science: you must first understand their strengths and weakness. Falsifiable models are best used when there are a lot of knowns and only a few unknowns. Climate change science is still a fairly new field of study, therefore, to impose passing falsifiable models as the standard for being included in the body of science is to cut off the conversation before it has even begun. For example, what sense would it have made to have demanded a passable falsifiable model for AIDS to be deemed a disease that actually existed until after the discovery of HIV?

Sometimes you just need to be patient.

trafn wrote: I then pick up that same bullet, place it in a gun and fire it at you from point-blank range. Now you are dead. So, do you get the difference the speed of change has to do with it?

The discovery of HIV came years into the process, and if anyone had demanded "Show me a falsifiable model or all research stops" in the first year or two, then people would still be dropping dead from GRID.

trafn wrote: It's not time for demanding a falsifiable model for climate change science, yet. It's still too early for that (i.e. - too many unknowns).

trafn wrote: many people argue, and reasonably so, that the current changes we're seeing from M2C2 are minuscule and measured in 0.xxx's.

trafn wrote: Yet, given things like the lag time factor and trigger points, ...

trafn wrote:
@Tim the plumber:*

1. I take a bullet and toss it gently at your chest. It bounces off your chest onto the floor causing you no harm. I then pick up that same bullet, place it in a gun and fire it at you from point-blank range. Now you are dead. So, do you get the difference the speed of change has to do with it?

2. If you're talking about past levels of CO2, they've been accurately measured through deep ice core samples. If you don't know what those are, you can google them.

3. In the beginning they did not know what the cause of AIDS was. Originally, it was called GRID (Gay Related Immunodeficiency Disease) and it was classified as a cancer which afflicted only homosexuals. The discovery of HIV came years into the process, and if anyone had demanded "Show me a falsifiable model or all research stops" in the first year or two, then people would still be dropping dead from GRID. It's not time for demanding a falsifiable model for climate change science, yet. It's still too early for that (i.e. - too many unknowns).

* - ask an intelligent question, get an intelligent answer.