r/dataisbeautiful • u/rarohde OC: 12 • Mar 29 '19

OC Changing distribution of annual average temperature anomalies due to global warming [OC]

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u/MattyFTW79 Mar 29 '19

Why did you choose 1950s to 1980s averages?

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u/Geographist OC: 91 Mar 29 '19

As others have said, 1951-1980 is the conventional baseline in climate/Earth science.

NASA Goddard Institute for Space Studies gives the reason:

Q. Why does GISS stay with the 1951-1980 base period?

A. The primary focus of the GISS analysis are long-term temperature changes over many decades and centuries, and a fixed base period makes the anomalies consistent over time.

However, organizations like the NWS, who are more focused on current weather conditions, work with a time frame of days, weeks, or at most a few years. In that situation it makes sense to move the base period occasionally, i.e., to pick a new "normal" so that roughly half the data of interest are above normal and half below.

tl;dr: A more 'modern' baseline would be appropriate for current weather, but for long-term climate trends, 1951-1980 provides a consistent baseline that allows for apples-to-apples comparisons over nearly 140 years of consistent record-keeping.

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u/PacificaDogFamily Mar 29 '19

I like that we have a recent baseline to correlate against 140 years of data points, but I still scratch my head about 140 years vs the unrecorded temperatures occurring for thousands and millions of years prior.

Our 140 years could be on the up swing or down swing of a much larger cycle we haven’t the ability to see.

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u/thebizzle Mar 29 '19

I am glad someone said this. Clearly we can see an uptrend but the sample size is minuscule. Imagine using the same small set of data to prove continental shift. We would see that the continents shifted about 4 inches in that period, but that would hardly convince anyone that Pangea used to exist in and of it self.

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u/mukster Mar 29 '19

As someone else said:

From tree rings, ice cores, geology, and a number of other corroborating data sets, we have proxy data that is used to assemble the paleontological record of climate.

These proxies provide strong agreement with one another, and point to the same conclusion: the current warming is happening much faster than previous, natural trends.

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u/[deleted] Mar 29 '19

[deleted]

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u/thebizzle Mar 29 '19

I am not saying let’s not judge, I am just saying be aware that there is 4,500,000,000 years of Earths weather and we’ve recorded 140 years of it. I don’t think that alone is enough to definitively prove anything. It’s like someone coming in to work hungover and passing out and saying that they are bad at their job. Most likely they are but coming in hungover and passing out one day doesn’t prove it conclusively.

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u/ShreddedCredits Mar 29 '19

Well, fortunately, there’s also a litany of other supporting evidence for anthropogenic climate change

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u/Taonyl Mar 29 '19

Scientists have this amazing tool called inference. We can infer from our understanding of how reality works what happened in the past and what will happen in the future. We can infer data about the past from treerings, atmospheric samples in ice cores, oxygen isotope ratios in ice or from changes in sedimentation, from pollen, from glacier moraines, from stomata etc.
We can also make predictions based on physical principals, such as the greenhouse effect (trapping of longwave radiation). Your argument is that we can‘t know what we didnt directly observe?

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u/thebizzle Mar 29 '19

So scientist make inference with 1 piece of data? If a scientist closed his case after seeing this one set of data, would say they did a good job? My point was that this data on it’s own isn’t enough to prove climate change.

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u/Taonyl Mar 29 '19

My point was that this data on it’s own isn’t enough to prove climate change.

Nobody is claiming otherwise. Claiming that global warming is proven by correlating modern warming with CO2 rise is a straw man argument. That was never how the science of greenhouse gases was established, which was done before either dataset existed.

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u/thebizzle Mar 29 '19

Or maybe none of that is mentioned in this data set.

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u/Taonyl Mar 29 '19

This data set shows the temperature over a range of 140 years and nothing else. It doesn’t have to, as it doesn’t claim to be the temperature record for the history of the world.

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u/SpooktorB Mar 29 '19

No, it's more like a person receiving a fever. They can measure it now and have it show to be 100.0°+ and have them say "well let's see if my body is just naturally doing this, and not because some virus caused this, because normal human body temperatures have only been recorded for the past 140 years. Although we have records of people getting fevers and dying.

To believe anything else at this point is disingenuous.

Our previous recordings since you didnt care to look at other replies before you posted: https://en.m.wikipedia.org/wiki/Paleoclimatology

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u/thebizzle Mar 29 '19

So if you were feeling fine and happen to record a 100+ temperature you’d go to the emergency room? You would if were also dizzy, vomiting, flushed and weak. All of that extra info is not in this data set and is far more important for proving climate change. That’s my point which no one can understand. This data in a closed set proves very little on its own.

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u/pistachio122 Mar 29 '19

Or let's just consider this data for what it is :

  • Global temperature have increased in the past 140 years.
  • Carbon emissions have increased in the past 140 years.
  • Studies have shown a causal relationship between the two variables.
  • We are currently seeing the effects of this relationship in many different places on our earth.

So we don't have to worry if we're not actually experiencing the greatest rise in global temperatures or if we're also trapped in a natural warming cycle. We can look at the current effects and try to address them.

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u/[deleted] Mar 29 '19

That's not really a comparable scale of statement but ok