Note:
On average, climate models assume
+3 degree C. of warming from a doubling
of the CO2 level -- that's a wild guess
from the 1970's, still used today.
The actual warming rate since 1950,
if all warming is attributed to CO2,
( a worst case estimate )
is +1 degree C. of warming
from a doubling of CO2.
The +3 degrees estimate,
which matches the predictions
of the average climate model,
explains why the models,
on average, predict triple the
global warming that actually
happened.
The models are obviously wrong,
predicting far too much warming.
And so are the
estimates for future
growth of CO2 levels
in the atmosphere,
that are used
for long-term CO2
assessment studies.
Here's the story:
The Fourth National
Climate Assessment
from the U.S. Global
Change Research Program
( wild guesses of the future climate )
assumes rapid CO2
concentration growth.
The climate modeling
research community
( computer gamers, actually )
have four estimates,
designated as
RCP2.6,
RCP4.5,
RCP6.0 and
RCP8.5.
RCP stands for
Representative
Concentration
Pathways.
RCP4.5 and RCP8.5
were used for
he Fourth National
Climate Assessment
( NCA4 ),
primarily RCP8.5.
The NCA4 states,
“RCP8.5 implies
a future with continued
high emissions growth ... "
(Executive Summary, p.7).
RCP8.5 is implied to be a
“business as usual”
CO2 growth scenario.
But that is not true,
just like all other aspects
of "climate change",
except for one claim,
based on real science:
Lab experiments
do prove CO2
is a greenhouse gas,
that has a mild warming
effect in a closed system
experiment.
CO2 measurement data sets
are available from the South Pole,
since 1957, and from Mauna Loa,
since 1958.
Their annual
CO2 values
were similar
in the late-1950s
( at 315 ppm ),
but Mauna Loa data
have been increasing
slightly more than
South Pole data
and both
now exceed
400 ppm.
The pre-industrial
starting level for CO2
is 270-280 ppm.
based on air bubbles
in Antarctica ice cores.
RCP8.5
abruptly deviates
from the historical trend,
to attain CO2 levels
of 936 ppm
in the year 2100.
The CO2 growth rate
would have to
immediately depart
from the historical pattern
towards more than double
of any other forecast,
or RCP.
The RCP8.5
acceleration of CO2 levels
should have started years ago,
but ongoing measurements
show that is not happening.
RCP8.5 is
a flawed projection
for the future, not a
“business as usual”
estimate.
RCP8.5 is
an energy-intensive
CO2 level growth
scenario, as a result of
high population growth
and a lower rate
of technology development.
Coal comprises nearly 50%
of RCP8.5’s energy mix,
something not seen since
early in the last century.
RCP8.5 has been called
a “return to coal” scenario
The population projection
is at the high limit
of the United Nations'
population growth estimates
population growth estimates
( the UN is known for far too high
population growth scenarios. )
Its primary energy consumption
projection lies at the 99th percentile
probability, through most
of this century.
of this century.
RCP8.5 is a compilation of
very low probability
assumptions yielding
a very unlikely, very high,
CO2 concentration
at the end of our century.
We have a 60-year record
of CO2 concentration
measurements.
CO2 concentrations in 2100
will likely fall in the 565-680 ppm
range, well short of the 936 ppm
indicated by the RCP8.5 estimate.
The RCP8.5
estimate
estimate
would be a
+6.5ppm / year
CO2 level increase
from 2019 to 2100.
The CO2 level
is currently rising
at an annual rate
of only +2ppm / year !
RCP8.5 was based on
low probabilities,
and questionable
assumptions
RCP8.5 is not
“business as usual”.
It assumes the population
will be rising rapidly,
ignoring recent low birth rates,
technological progress stagnating,
and we'll suddenly start using coal
for most of our electricity generation !
RCP8.5 is propaganda
-- a motivation tool
-- a motivation tool
for climate alarmism.