Humans have less impact on climate?

[Slimething]

The IPCC is predicting consequences that are severe. I have a scientist friend working for the CSIRO on this, including work on the models. He does believe AGW is real, but he thinks we can work to manage the consequences, but that governments are ignoring those consequences. He does not believe there will be a runaway effect, but he does believe the temperature will keep rising for many years to come.

I have to side with your friend but that may be wishful thinking on my part. The IPCC predicting severe consequences is difficult to understand because, although the warming of the planet is confirmed, the computer models being used right now to forecast the future temperature of the Earth are not validated. So, at best, I think of dire predictions as guesswork and I hope they're too extreme.

The factor that disturbs me the most of the phenomenon, as I understand it, is the lag time between the time humanity makes a relevant change and the onset of effective relief from those changes. It's kind of like standing on your brake pedal and hoping you did so in time. But, right now, it's all guesswork. Very astute guesswork but it's going to take a little more to convince the people that matter to make the needed changes.

What are the errors with those models? From what I have read, the only error is that they underestimate the effects of AGW, since the Arctic and glaciers are melting faster than was estimated.

Like you, I've read a lot of point/counterpoint on this issue. I don't question that GW is occuring. However, the counterpoint that I find credible because I've seen it from lotsa sources and not just the hotheads (excuse the pun) is that, since the predictive models have been used to forecast the rate of warming, the mean temperature of the planet has not warmed nearly as fast as predicted. And, frankly, mean temperature must, in my opinion, be the empirical test for global warming as it's the only absolute we have.

Of course, secondary effects like ice melting are the effects we will all feel and will make our lives miserable so I'm not discounting them. There's a dichotomy taking place in GW discussion and that's the fate of the planet vs the fate of humanity. I don't really think we're as much concerned about the planet itself as we are for ourselves. However, many in the "anti" camp are critiquing GW prognostications on the fact that they won't affect the planet all that much and turn a blind eye to the fact that we humans are much more vulnerable than the rock we live on.

 

[a_unique_person]

I have to side with your friend but that may be wishful thinking on my part. The IPCC predicting severe consequences is difficult to understand because, although the warming of the planet is confirmed, the computer models being used right now to forecast the future temperature of the Earth are not validated. So, at best, I think of dire predictions as guesswork and I hope they're too extreme.

Hope is not a recognised risk management method.

When he says we can manage it, he means we can, but it will cost a lot of money, and cause a lot of pain. That is, he doesn't see the human race going extinct. He does, however, think that just preventing the AGW would be a lot more sensible. I guess he just doesn't see anyone being able to change the human need for cheap energy. When I asked him if oil running out would help, he said there is heaps of oil out there. It's going to cost a lot more to use, but we'll just process all that oil sand, etc anyway. He is also one of those incurable optimists, which does worry me.

 

[Cuddles]

I was asking why it matters if it is a consensus, i asked if a majority somehow made it correct. you said the preponderance of the data is what matters (which boils down to majority again, just not in people but in research). I am not getting anywhere in this discussion by having you restate your opinion. So lets just forget it. a consensus points to truth in your opinion, but not mine. perhaps that should be a whole different thread all together.

A concensus doesn't necessarily mean something is correct, but depending on who holds the concensus it can support it. In this case you have climatologists, who have proabably spent most of their lives learning how the climate works, most of whom look at the data and come to the conclusion that humans are the cause of at least part of the current warming trend. This is not just asking the average Joe on the street, these are the people who are most qualified to interpret the data, and the fact that most of them come to the same conclusion very strongly suggests that this is the correct conclusion to draw from this data. In most cases the mainstream view is correct because it gets to be the mainstream by standing up to repeated testing. They may have laughed at Galileo, but they also laughed at an awful lot of people who were wrong.

Of course, no scientist would use this as a scientific argument to support their theory, but it is very useful when discussing things with laypeople to be able to say "Most experts in the field think this is the case". Appeal to authority is not a fallacy when you appeal to the correct authority.

Edit : With regards to a_unique_person's apparent ambiguity over whether it is the data or the concensus that is important, the concensus of scientists should lead the layperson to assume that the data supports their conclusion, otherwise they wouldn't all have reached the same conclusion. Equally, if there is a lot of good evidence for a conclusion, one could reliably assume that that conclusion is the concensus among experts in the field.

 

[Beerina]

AUP- Yes indeed, civilisation is an artifact of stable conditions. While humans thrived in the last ice age and emerged from it in a strong position, we could not support present populations through another one- and may be unable to do so through a period as warm as the Cenozoic optimum
The question is one of time scale.
The geological data cannot distinguish rapid changes on the same scale as day to day records. We are comparing apples with aardvaarks.That does not prove rapid change did not happen. Interestingly, when we start to get short term records from ice cores, the evidence suggests that extremely fast change is the norm rather than the exception.

One of the things that really scared me was about 10-15 years ago, when some scientists released a report that ice ages may come on in as little as a couple of years. It wasn't necessarily a slow cooling over a thousand years or more.

 

[DeviousB]

Shut off the thermo-haline circulation (THC) and Europe gets a new ice ace in a very few years (not so much The Day After Tomorrow, more The Next Birthday But One).


One of the other climate threads here included a graph of reconstructed local temperatures from the end of the Younger Dryas period. This was a time at the end of the Pleistocene when the general trend towards deglaciation suddenly reversed for about 1000 years over a fair swathe of the northern hemispere. It is currently believed that this sudden freeze may have been due to disruption of the THC by meltwater from deglaciation. When the THC eventually reasserted itself the subsequent warming was similarly as dramatic.