If you’re 27 or younger, you’ve never experienced a colder-than-average month | Hacker News Reader

If you’re 27 or younger, you’ve never experienced a colder-than-average month

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38 pointsjgv21 comments

Too bad such an important topic is covered by such a shitty post. Obviously the expert source referenced in the article http://www.ncdc.noaa.gov/sotc/global/2012/10 is referring to global average temperature.

Average over what timescale? If you take it back 250 million years, then every human being alive has seen only colder than average months.

Just about to post something similar. So much of the global warming rhetoric is just FUD for people who don't understand statistics. For people claiming to know that the increase in temperature for the last 100 years is significant, what is the standard deviation of the change in global temperature over 100 year periods for the last 100k years?

>what is the standard deviation of the change in global temperature over 100 year periods for the last 100k years?

I see your point, but we don't have that information and probably never will. We don't have strongly statistically significant measurements until ~1600. But we have to operate with some uncertainty to make decisions worth trillions of dollars.

We know the increases we've seen in the past century are of a much higher magnitude than what we saw in the few centuries before that. We believe this is true for at least 1000 years back (see the hockey stick curves). We know the increases in the past 100 years are correlated with human actions, especially greenhouse gas emissions. It is (IMO) common sense to hypothesize this correlation is a causation; we know the causation doesn't go the other way, and we know there are no confounding factors (i.e. the same thing that caused the heating caused us to emit way more greenhouse gases). This is where climate change skeptics attack, which is unfair because it is impossible to prove a causation. If we assume the correlation is a causation, we know the increases we have seen would not have naturally existed. And this is what matters to many scientists.

The increases are not "significant" in the statistical sense per se, they are significant in the possible effects on our world.

> we don't have that information and probably never will

http://joannenova.com.au/2010/02/the-big-picture-65-million-...

It's not useful to compare 65 million years of data + huge error bars with 1000 years + medium error bars with 100 years + tiny error bars. The uncertainty of what was happening 50000 years ago may very well be greater than the changes we are worrying about in the past century (I don't know this for sure, I can't find error estimates in your link).

Er - yes. The title alone suggests that the average temperature must have been calculated from a longer time series of data.

Given the temperatures for each of the 27 x 12 = 324 previous months, the mean of those figures must be within the range somewhere....

A stupid argument. Humanity has only been around for 1/1000th of that time.

This title is nonsensical. The temperatures referred to are global averages. Yet the only ones people can actually experience are local temperatures, which sometimes are lower than average.

It's even less relevant for people who don't go outside. The only temperatures they ever experience are set to their own personal preferences, or the preferences of their caretakers.

Or the harsh whims of building maintenance. I wonder what percentage of thermostats sold in the world are the ones in offices not wired to anything...

How is this "beyond astonishing"? 27 years is minuscule on in a geologic time scale. Climate trends are measured in hundreds and thousands of years, if not more.

And between April 1889 and October 1925, there wasn't a single warmer-than-average month.

ftp://ftp.ncdc.noaa.gov/pub/data/anomalies/monthly.land_ocean.90S.90N.df_1901-2000mean.dat

An interesting anomaly is the warming between the 1860s and 1940s. Especially given the comparatively slight amount of CO2 released in those decades compared to our own.

Temperature norms may move across greater timescales than just 100-150 years. Of course, if we were to explore that, the discussion goes off the rails into talk about the "MWP," "historical reconstructions," "Mann, et al.," and other murkily useless topics for internet bulletin boards.

> above the 20th century average

so, we're 12 years into this century, and he's comparing to a 100 years span. 27 years which means 15 years of the last century. selective number picking. meaningless post, move on.

Unless you live in the UK or France (to my certain knowledge) and probably a huge chunk of the world beyond that.

It appears to mean a global average.

Which underlines the lack of any meaningful truth in the key statement.

Why? (Unless they somehow live wholly isolated from global temperature affecting their experience.)

One might question how you could "experience" a global average temperature, unless perhaps you travel a whole lot.

This is an important topic, but "If you’re 27 or younger, you’ve never experienced a colder-than-[global]-average month" strikes me as a rather silly statement.

If I said that it was 55 degrees in Chicago today, would my statement lack any meaningful truth if the temperature was closer to 58 near the lake?

The idea that making the statement that monthly global temperature averages haven't managed to be lower than the historical average once in 27 years should be seen as utterly irrelevant bordering on deceptive because there was a cool January in my neighborhood last year is really making me ill right now.

It's not even pedantry, simply solipsism.

In Poland we call hard winters (well, for the most of the world, our normal winter is hard enough) 'winter of the century'[1]. We had 5 such 'winters of the century' in 20th, last year we had the first one in 21st where the unofficial records of cold closely matched the official records of 1928 and 1939.

[1] you'll need google translate http://pl.wikipedia.org/wiki/Zima_stulecia and unless you're Russian you better grab a warm coat before reading.

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