Climate of a Lifetime

After last year 2014, being the hottest since records were kept, there have been the predictable complaints that the record is somehow suspect. From quibbles about the probability it was the warmest; it was the definite odds-on favourite, to raising dark insinuations of wholescale or widespread falsification of the record. Because of homogenisation, or something. A disinclination to accept reality that ranged from the sublime to the ridiculous.

But like the top-stone on a pyramid last years record only makes the point, it does not define the whole shape.

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There have been many excellent responses to these attempts to disparage the record. This post at Variable Variability is good, pointing out that it is the whole trend that matters and the raw data would give a greater trend because the sea surface temperature data has been adjusted downwards, a manipulation to reduce the trend far larger than any shifts made to the land based measurements, and an alteration that dominates the record because the oceans cover so much more surface than the land.

Although it is impossible to dissuade someone convinced EVERY record of every sort has been falsified to show warming, I suspect most people are aware that from weather stations to ship measurements, from ice-cores to tree-rings, lake sediments, boreholes, diatoms, pollen… every source of information shows the recent warming, rejecting an attempt to make that record as accurate as possible because scientists and mathematicians find ways to improve its quality seems ridiculous. Even more so if you try and imply that contrary to every other source of evidence the effect of that data-cleaning is to convert a static or cooling trend into a large warming signal.

A warming signal that is seen in the overwhelming majority of all sources of raw and proxy data.

And so it is with the change in climate that people have experienced in their lifetime. 2014 was the warmest year in a clear pattern of warmer and warmer years that is almost certainly unmatched since the last melting of the ice-caps that began the Holocene.

Somewhere recently I saw an analysis of how many people would have had the second half of their life warmer than the first using the CET. or something like that, if anyone recognises the link from this garbled description, please put it in a comment. The point was that while there were warm and cold periods in the last few centuries, the cooling periods had occasional hot years and the warming times occasional cool periods, so for most starting dates the two halves of a lifetime would have very similar average temperatures.

This reminded me of Open Mind‘s excellent exposition of why the hiatus or pause in warming is illusory, an ‘end effect’ of noise that can mislead without rigorous statistically defined constraints on what is, or is not, a meaningful divergence from the long term, and predicted warming trend.

Here is a visual presentation of the total shape of what we know about past climate over many timescales, but focusing on the climate a person will have experienced if they were now hoping to retire soon, or at least make it to the biblical three score and ten…

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Script

The climate always changes. The warming is natural. It was warmer, and colder in the past. It is a rebound from the little ice age. We are still warming from the last ice age. The warming has stopped. There is no warming.

Just some of the things said about the climate.

It is certainly true that since life got a backbone and could photosynthesis the climate of the Earth has bounced between very hot and snowball cold. Since the dinosaurs went extinct during the rise of mammals it has gone from ice free to very cold. With the evolution of apes and hominids during the last five million years it continued to cool With cycles of ice ages and brief warm peaks. The last six thousand years, the lifetime of human and agriculture and civilisation , has been one long peak.

All of these timescales are relevant to some degree, if only to inform us of what the climate CAN do.
But let’s look at a human lifetime of climate. Not quite the biblical three score and ten, but the data match a Beatles song….

64 years of global temperatures.

With the trend for the whole period.

Here are the record hot years.

With the pattern of rise, perhaps this is what has given some people the idea there is a pause, the levelling off of record hot years.

But hindsight can give another perspective. The coldest year before any year also gives a pattern of change. Not so much of a change in trend there, and both conform to the trend before 2000.

So for someone who has lived since the middle of the last century, the coldest years are now warmer than the warmest years of their childhood. Whatever swings up and down happen within a decade or so have made little long term impact on the change in climate over their lifetime.
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Updated video for ‘better’ sound/picture quality?

SOURCES

NOAA

GISS

WoodForTrees

“All palaeotemps” by Glen Fergus – Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons –

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