UK Met Office Scientists Forced To Alter Temperature Benchmarks In Face Of Rapid Change

[hatrack]

EXETER (Reuters) - Global warming is forcing weather scientists at the Met Office to change the way they compare seasonal temperatures, they said on Wednesday. The national weather forecaster compares average temperatures to the long-term average for 1971-2000, but forecasters say this benchmark is increasingly irrelevant and is being supplanted by new ways of calculating the average.

"Climate references are changing, so there is a need to revolutionise the way we do this," climate scientist Richard Graham said on the sidelines of a Met Office conference. The last nine summers have been hotter than the 1971-2000 average of 14.1 degrees Celsius, and forecasters expect this summer will be no exception.

For the first time, weather scientists are generating a new 30-year average, calculated using 15 years of historic data and 15 years of predicted future temperatures, Graham said. Future temperatures are calculated using a forecasting system introduced this year and give a far more accurate picture of how individual summers compare over a long-term period.

"This new method is great for business uses; it could be of use to the public forecast as well," Graham said.

EDIT

http://uk.reuters.com/article/domesticNews/idUKL0673883720070606

[krispos42]

1. Is that average right?

14.1 degrees C is only 57.4 degrees F.

That's pretty lousy for summer, isn't it?

[pscot]

2. Well, we are talking about England

There's a reason they invented tweed.

[muriel_volestrangler]

5. It's the average over day and night

See http://www.metoffice.gov.uk/climate/uk/averages/19712000/mapped.html for the various measures over the country - for instance, for me on the south coast, the summer average is about 16 degrees C; the daily minimum averages about 11 degrees, and the maximum 21 degrees C. But yes, British summers are cool, compared with a summer almost anywhere else - we're quite far north, and the ocean currents cool us during the summer, compared with continents.

[Nihil]

3. WTF?

> The national weather forecaster compares average temperatures to the
> long-term average for 1971-2000, ...
> ...

> For the first time, weather scientists are generating a
> new 30-year average, calculated using 15 years of historic data
> and 15 years of predicted future temperatures, Graham said.

In other words, they are taking 15 years of factual data and polluting
it with an equal amount of untested guesswork in order to derive this
new figure they are pretending is a "30-year average" and which the
public (who have always been used to the Met Office reporting data
reliably rather than making it up) are going to believe is accurate.

:wtf:

> Future temperatures are calculated using a forecasting system
> introduced this year and give a far more accurate picture of
> how individual summers compare over a long-term period.

Just to clarify, the 15 years of guesswork that they intend to use
with their previously factual comparisons are being calculated using
a new system (< 6 months) whose accuracy is yet to be determined and
which is being created on the fly due to the unknown territory that
we currently find ourselves exploring.

They are taking their records (from 1659!) and saying that their
adopted projection of this unknown trend is better than presenting
the *facts* and allowing the change to become visible to the public.

:mad:

[muriel_volestrangler]

6. It's assuming that everyone knows temperatures are increasing

Rather than just sat "this month was above the average" every single time, it gives an idea of "this month was warmer than we expected". As an example, the page for May 2007 says England was 1.1 degrees C above the 1961-1990 average. May (as opposed to April) didn't seem very warm to me - and if that comes out as 'warmer', all we get is the "it's always warm these days" message.

Anyway, the article says:

While the Met Office is likely to continue quoting the 1971-2000 benchmark in its public forecasts, Graham said the new forward-looking average is preferred by the scientists who produce the forecast because it takes into account the effects of global warming.

[Nihil]

7. That's a view that many people are actively fighting.

> Rather than just sat "this month was above the average" every single
> time, it gives an idea of "this month was warmer than we expected".

But that is the point: they are now judging the temperature against
a guess, not against actual evidence!

To refer to your quote from the article:
>> While the Met Office is likely to continue quoting the
>> 1971-2000 benchmark in its public forecasts ...

This indicates (to me anyway) that there is no hard and fast policy
about the usage of said benchmark. It also suggests that the option
to discontinue is internal and thus political.

>> Graham said the new forward-looking average is preferred by the
>> scientists who produce the forecast because it takes into account
>> the effects of global warming.

NO IT DOESN'T. It takes into account one particular model out of the
dozens (hundreds?) of alternatives, none of which have been proven
to be accurate and thus subject to constant refinement ... somewhat
destroying the concept of a "benchmark" or "reference datum".


They have stated that their model shows increasing temperatures.
There are three results here - all (IMO) bad:

1) If the data matches the model, the reports will be "as expected"
which is translated by most people as "normal". It isn't "normal" but
the concern level in the public will drop and they will carry on being
wasteful (and largely ignorant).

2) If the data exceeds the model, the reports will show concern that
things are "worse than expected" but i) it will start with small amounts
of discrepancy that can easily be dismissed by denialists and ii) it is
subject to their (truthful) attack that "but that's only one model".
The result will be to numb the public and make them ignore the reports
as "crying wolf" and carry on being wasteful.

3) If the data is lower than the model, this will be manna from heaven
for the denialists as they can point at being "better than expected,
thus proving that the climate changes models are wrong and just hysteria".
Yet again, the result will be that the uneducated majority will carry on
being wasteful (some even deliberately increasing waste in "revenge" for
"being cheated by the scientists").


There are just SO many things wrong with this approach that I am gutted
that they would even consider it.

So much for science-led policies ...

[jimlup]

4. Public will not understand

The public will miss the idea. They will only notice the average and realize that the average is a changing quantity. If this is adopted in the US no one will know that the frog in the pot is boiling. He will just sit in the pot and wait for it to boil.