The best science paper,
I discovered in 2017,
was published in 2015 !
Read the full paper at the link below:
Following are
three long quotes,
from the beginning (1),
middle (2),
and end (3),
of the paper.
(reformatted for
easy reading,
on smart phones)
This 22-page PDF paper,
is a rare commodity:
A fair and balanced report,
on the current state,
of climate science,
(in 2015):
"Climate Change:
Evidence, Models, and Speculation
by Leif Svalgaard,
Stanford University
September, 2015
(1)
"Climate Change is real.
The climate is ever changing.
Climate change is an observed fact
happening today as in the past,
and certainly in the future as well.
Conventionally, ‘climate’ is defined
as average weather over a 30-year interval,
so statements that a certain year
has been ‘the warmest ever’
or that yesterday was colder than today
have little significance for the climate record.
In addition, the climate varies vastly
over the surface of the Earth
and for the land area
with altitude above sea level,
so it is difficult to characterize
the global climate
by a single measure.
Nevertheless, the difference between
the yearly average temperature
and its 30- year average,
(called) the temperature anomaly,
is conventionally used
as such a measure,
when averaged over the globe.
[the word ‘anomaly’ as used here
does not carry the usual meaning
of ‘oddity, peculiarity, or incongruity’],
Herein lies a problem:
the measurements
are not
evenly distributed
over the globe
(in space and time),
and are particularly sparse
over the oceans
and high latitudes.
Temperatures over Land
Various schemes
are used to extrapolate
(or fill in)
the sparse data
in order to approximate
global coverage.
Needless to say,
such filling in
(making up data)
is open to criticism
and uncertainty.
In addition, various effects,
such as the
Urban Heat Island effect
and changes related to
station siting issues
and ‘correction’
of perceived or real errors
in the record,
lead to ever changing
‘adjustments’ of the record,
curiously almost every new adjustment
is in the sense of reducing early values
and increasing recent values,
thus constituting (creating) a part of
literally man-made global warming.
Adjustments made
to correct faulty data are,
of course, both necessary
and desirable
as we shall see in the section
about the long-term variation
of solar activity.
... It is probably significant
that the (temperature) increase
from 1910-1945
is very similar to the increase
from 1975-2002,
and that there was a ‘pause’
from 1945-1975
and a clear hint
of a similar plateau
(from) 2003-2015.
... Analysis of the
U.S. Historical Climatological
Network (USHCN)
shows that less than 10%
of the data survives
in the climate record
as unaltered data."
...
(2)
"Climate Variables and Models
As far as we know
there are the following
parameters or variables
influencing our climate
on time scales
less than a million years
(thus excluding the slow
evolution of the Sun):
1) Earth orbital and
orientation variations
2) Changes in ocean circulation,
NSO and others
3) Solar Irradiance and activity
4) Volcanic aerosol emissions
5) Greenhouse gas emissions
6) Land use (cities, logging, crops, grazing...)
7) Regional differences
8) Stochastic variations of
a complex, non-linear system
9) Diverse unpredictable catastrophes
The parameters are not all independent
and couplings and feedback
make for intricate interplays
and confounding correlations.
With so many parameters in play,
one can usually (and easily)
find some combination
that ‘models’ or mimics the
(uncertain) variations of
global temperatures
over a cherry-picked
time interval of choice."
...
(3)
"Conclusion
Global Warming,
or Climate Change,
or Climate Disruption,
just to mention some of the
(increasingly scary)
monikers
that are being deployed
these days
has become
a divisive political issue,
seemingly divorced
from scientific discourse.
If it were not for
the high-jacking
of the subject
by politicians,
environmental pressure groups,
and plain wishful eco-thinking,
one would conclude
from the present overview
that Climate Science
is a vigorous field
with healthy debate
and exciting
interdisciplinary facets
rather than a moribund body
of ‘Settled Science’
without prospects
for further progress,
perhaps like Physics
at the end of the 19th century.
However, science is ultimately
a self-correcting process
where the scientific community
plays a crucial and collective role,
so we will eventually get it right,
with or without political
and societal interference,
if the last two millennia
are any guide.
In the meantime we:
“may hope to enjoy future ages
with more equable and better climates”,
Svante Arrhenius
[the originator of the greenhouse gas theory, in 1896]