re: #249 Purpendicular

re: #251 Purpendicular

For someone who claims to not have studied this topic, you do seem to have dug up many of the talking points common in the denial-o-sphere, from the BBC poorly written article to cosmic rays.

I realize English is not your first language, so some of what you have written can be dismissed as being awkward translations, yet some of your other claims are either wrong or misleading.

Let’s touch on some of them:

But it would appear that the observed data is not necessarily agreeing with the models. If a model is good, it should be able to fit the data.

On the contrary. Current models do a very good job of reproducing the nature of the observed record. Inherently, the climate system is a chaotic system, which also receives both non-random and random inputs from outside.

As such, any physical model that attempts to replicate the real world must include such qualities, and that means that any given run of the model will turn out different than the others. Thus climate models are run many times, and the composite of the runs give a distribution of possible outcomes. To “fit” the observed data the model runs only need to be within the error of the observations as well as the observed data being within the distribution of the model runs. Furthermore, there are several different large coupled climate models, and comparing the output of the different models is not uncommon, and the outputs can be combined into a larger set from which to determine likelihoods.

When done so, comparing the observed data versus the model runs show that the models do very well.

Indeed, over time the models have become better, as more detail of the physical world is included. An over view of this, with a comparison of first, second, and third generation models can be found here:

—-

Suppose that the Hockey Stick is true. We then have data that says that the earth’s temperature is flat. OK, has it been flat forever? If it not always was flat, what are the reasons that the temperature of the globe has ever changed? Or has the temperature been flat for 4 billion years? What about the Ice ages?

This is confusing. First, there is no single “hockey stick”… there are many. Secondly, it is called a hockey stick simply to provide a mental image to people who aren’t looking at the actual graphs. Thirdly, the graphs of the various physical quantities never, ever have claimed to cover “forever”, whether in regard to “flat”-ness or any other quality. All physical measurement graphs has specific time periods that they cover. There are many reasons climates might change, and given 4.3 billion years one would reasonably expect to see all sorts of phenomenon.

None of which precludes what is known about what humans are indeed doing to the planet, which is directly measurable.

—-

I would really appreciate if someone could link to a publication that reconciles the historical records and the “Hockey Stick”.

You’re confused. The “hockey stick” graphs are the graphs of the physical data, from records of various sorts!

As a starting point, I encourage you to read the AIP website Discovery of Global Warming, which is my customary primer for this subject, for it will answer many beginning questions.