So all we need to do in order to follow these stations, is filter out those in the northern hemisphere and re-run the job.
Isn't this the same sort of thing that the tree ring people did? There were some statistical points that looked like they were going to mess with the results so they threw them out? They only threw out a few outliers, which is standard practice, but here we're throwing out a whole class of data.
It's also interesting that the northern hemisphere is warming up faster (if the methodology chosen by the author is correct). Since most of the earth's landmass is on the northern hemisphere (as well as most of the developed countries), doesn't that mean we're in trouble?
By looking at each station indiviually instead of compressing them to an unevenly weighted average, we will be able to clearly deduce how the weather has changed through the years recorded.
This still doesn't take into account the density of stations. Also, trying to compare stations like that, with the curves obscuring each other, is a crime of presentation. If you took the time to do a regression on the datapoints with the other data, it surely would not have took much longer to code for regression on each of the individual weather stations (incorrect as that may be).
On a different note, the use of clojure was enjoyable, which deserves an upmod.
As I understand it, the tree ring thing was that the more recent data is distorted by pollution. That is, the width of each year's ring should be dependent on how warm the year was, but the increase in pollution in recent times has caused a decrease in the width of the rings laid down.
I'm torn on this article. I'm very appreciative of a real-world example of using clojure to manipulate data but at the same time it treats a trivial and entirely unscientific analysis of one data set as a complete, concrete and comprehensive summary of an entire field of science.
Well, there's a few problems. Gore didn't actually use the Mann hockey stick that is presented, although the hockey stick in 'An Inconvenient Truth' is very simliar (in that it omits the Medieval Warming Period)
Those commenting on the start date fail to realise that the start date of the data set he uses is 1929. You can't blame the author for that.
The fact that it's part of the 'head' or 'blade' of the stick is irrelevant, all of the 'handle' is based on multi-proxy reconstruction, which has major data problems, as the endless to-and-fro on this issue says. One of the major problems highlighted has been the use of tree-rings as a proxy, and the tree rings do not agree with the instrumental record. This is the famous 'hide the decline', where the authors sought out statistical methods (the trick) in order to splice the tree ring proxies with the instrumental records, which they really shouldn't have done.
The field of coming up with global averages from temperature datasets is so complex I won't even try and make a comment on that. Plus I don't know any clojure.
"global warming" is a phrase that has taken on a larger meaning than just increasing-average-temperature. his joke is obviously referring to the movement (he did capitalize.)
There is also the question of whether the net effect of the warming is a negative economic impact, and if so if "fixing" it is a greater cost to the economy than not fixing it.
That's very true. It may very well have a net positive economical effect.
But the problem with that kind of reasoning is that if it is going to have a net positive economic effect that we can rape & plunder mother nature to our hearts content and that simply isn't true.
Economic advantages are not all there is to look after, long term effects are important, and the absolute effect on economies is also important. In other words if our economy goes up because of doing something and some poor country loses all they've got then you could argue the net effect is positive because they didn't have much to begin with.
But that's definitely not how the world should work.
So we need to look past purely economic motives and at humanity (and to some extent the biosphere) as a whole.
>"But the problem with that kind of reasoning is that if it is going to have a net positive economic effect that we can rape & plunder mother nature to our hearts content and that simply isn't true."
I doubt that any serious environmental economist thinks this way. Economists do include non-monetary factors in cost/benefit analsyes, and the cost of environmental degradation which does NOT show up on profit/loss statements is one of the oldest topics in the field.
Dismissing the entire discipline of environmental economics as the work of "bean counters" is a really bad rhetorical start for any serious discussion of ecological policy, though unfortunately it happens often among the masses on internet message boards. I am really disappointed to see that these caricatures abound.
There are many examples of very precious resources being squandered because of profit motives, our stewardship of the planet could be much better, I doubt it could be much worse.
In less than 300 years, basically since the time that we started to industrialize we have remade face of the planet.
Point me to all those efforts at sustained management that ought to be a counterexample to those examples of wanton destruction of habitats and ecosystems for profit.
Everywhere that money is brought in to the equation sooner or later the ecology will have to suffer. Running an ecology as a business is simply not an option.
I know it has been tried many times and I know that there are plenty of people that probably have the best interest of their environment at heart, but from what I've seen to date the best thing we have done is to simply not mess with a large enough area and hope that it will recover.
Any attempt at large scale intervention, even from a positive viewpoint has sooner or later become a game of seeing how to use that resource within the letter of the law for maximum profit.
Rainforests, the Canadian forest management, wildlife preserves, the artic and the oceans.
The list really is endless.
Calling the people in charge bean counters is doing them a service, it means they're not actively involved in destruction on a planetwide scale that they are aware of.
I even leave open room for 'best intentions', but that doesn't mean their effects are positve. Not by a long shot.
Right now those places that are doing best in terms of species diversity and other parameters indicating relatively healthy ecosystems are those that we haven't gotten around to yet and those that we have utterly abandoned.
Environmental economics is a complete contradiction, you can not manage a tract of rainforest or a volume of ocean in a way that is at the same time good for the environment and ecologically sound.
We have basically taken out an environmental mortgage and have spent that mortgage on stuff that harms the environment, it will be a long long time before we are in a position to pay it back.
I realize this is not a happy picture, but sometimes it is better to open your eyes to what's really going on than to put on your rosy sunglasses and to hope that it will all go away.
There are lots of very uncomfortable conclusions that we may one day have to draw, there is a small chance that we will be in a position to guide those decisions if we start acting long enough in advance.
You are right that people have damaged the environment for personal gain in the past, but I still think that you are missing the point on what economics is about. In environmental economics researchers study why people use resources the way they do, how to design environmental regulation so that people will actually stick to it, and what resource use is likely to be in the future. "How to rape the environment more efficiently" is not a common topic of study.
Sorry, environmental economics was probably the wrong field to bring up. What we really want to know is whether or not these macroeconomic modelers take into account the value of ecological resources in their models. Tell you what, I'll scribble off a note to William Nordhaus and ask him. In my experience most academic economists have been very approachable.
Here's my letter:
"
Hello Dr. Nordhaus,
I have a question about the economic modeling of climate change. Do economists take into account the cost of ecological damage in their models?
I ask because this question came up in conversation a few days ago. A friend of mine claimed economic models were invalid because they only took into effect the monetary profit-and-loss effects of climate change and not the value of nature itself, but I wasn't sure if that was true. How does a resource like the Brazilian Rainforest enter into the model?
"The answer is that these are included conceptually in serious studies. The problem is that measurement has proven extremely difficult, so it is hard to judge whether the actual magnitudes are correct. WN"
I think it makes the case that economists do not consider ecological damage to be cost zero. However, it is hard to assign a hard objective value to it.
Hopefully one would also weigh moral costs in some way. As FiveThirtyEight[1] demonstrates trivial changes to global economies can mask tremendous changes to human populations.
The article is a good read regarding data crunching, but I take exception to some of his methodology.
Specifically, he's only using data from 1929 and on -- this is all part of the hockey stick's head. The 1920s are supposedly the start of the dramatic temperature increase. So of course the graphs don't show a dramatic slope change; there's no pre-1929, lesser-slope data included.
Edit: I'm not implying intentional omission on his part; 1929 is the earliest year available from NOAA (ftp://ftp.ncdc.noaa.gov/pub/data/gsod).
Exactly. That's about as selective as you can get.
No way of saying that hockey stick will appear if he includes all the data but the way he filtered out the end part and then stretched it is just being very selective with the data provided.
The reason why there is so much room for interpretation in all this data crunching in part is because of the troublesome normalization issues faced when consolidating data from so many different sources.
If there had been reliable weather stations in the last two millennia this would be completely different. But obviously that's not the case.
I have a project based on the Global Historical Climatology Network data, going back 300 years. This is based upon readings from actual thermometers on ground based weather stations, rather than tree rings or ice cores which are far more difficult to decypher.
The thing is that when you look at the data at the lowest level (individual stations) what you're getting is small snippets of temperature information. Some stations have been around for as long as 100 years, but I don't think that there are any single stations which span the full 300 years.
Isn't this the same sort of thing that the tree ring people did? There were some statistical points that looked like they were going to mess with the results so they threw them out? They only threw out a few outliers, which is standard practice, but here we're throwing out a whole class of data.
It's also interesting that the northern hemisphere is warming up faster (if the methodology chosen by the author is correct). Since most of the earth's landmass is on the northern hemisphere (as well as most of the developed countries), doesn't that mean we're in trouble?
By looking at each station indiviually instead of compressing them to an unevenly weighted average, we will be able to clearly deduce how the weather has changed through the years recorded.
This still doesn't take into account the density of stations. Also, trying to compare stations like that, with the curves obscuring each other, is a crime of presentation. If you took the time to do a regression on the datapoints with the other data, it surely would not have took much longer to code for regression on each of the individual weather stations (incorrect as that may be).
On a different note, the use of clojure was enjoyable, which deserves an upmod.