One NASA climatologist pointed out that nobody — including Spencer — knows what causes the mismatch
between temperature projections and satellite - based climate data.
Not exact matches
IPCC estimates, using the best and longest record available, show that the difference
between the 1986 - 2005 global average
temperature value used in most of the Panel's
projections, and pre-industrial global average
temperature, is 0.61 °C (0.55 - 0.67).
Our record is also of interest to climate policy developments, because it opens the door to detailed comparisons
between past atmospheric CO2 concentrations, global
temperatures, and sea levels, which has enormous value to long - term future climate
projections.»
In projecting climate variables such as
temperature, precipitation, and humidity, there is generally a tradeoff
between (a) the ability to produce high - resolution
projections needed to inform local decisions and model local responses, and (b) the ability to sample uncertainty.
These global
projections are consistent with an independent set of global
projections based upon the relationship
between temperature and rate of sea - level change over the last two millennia.
not one indication of a decoupling of the link
between anthropogenic forcings and resulting
temperature rise, even though RCP4.5 sees a central
projection well beyond that «two degrees» with its «real chance,» RCP4.5 hitting 3.1 ºC above pre-industrial by AD2300.
Note that the graph gives no indications of any «lost control», not one indication of a decoupling of the link
between anthropogenic forcings and resulting
temperature rise, even though RCP4.5 sees a central
projection well beyond that «two degrees» with its «real chance,» RCP4.5 hitting 3.1 ºC above pre-industrial by AD2300.
Current
projections point to average world
temperatures to rise
between 1.1 C and 6.41 C
between 1990 and 2100.
Raw climate model results for a business - as - usual scenario indicate that we can expect global
temperatures to increase anywhere in the range of 5.8 and 10.6 degrees Fahrenheit (3.2 to 5.9 degrees Celsius) over preindustrial levels by the end of the century — a difference of about a factor of two
between the most - and least - severe
projections.
Specifically, if sulphur emissions as estimated in Stern D. I. (2005) «Global sulfur emissions from 1850 to 2000», Chemosphere 58, 163 - 175 and the database supporting that paper are substituted for those that were used to produce the SRES and / or ABARE
projections, what is the effect on the global mean
temperature up to now, and the projected increase
between now and 2030?
On
temperature change
between 1850 - 1900 and 1986 - 2005, Canada, supported by Belgium and the US, proposed providing context for the two time periods, referring to the former as the early instrumental period, and the latter as the AR5 reference period used for
projections.
Focusing on the «pause» is mainly significant in context of the comparison
between climate model
projections and surface
temperatures... Attempts to spin 2014 as a possible «warmest year» is exactly that: spin designed to influence the Lima deliberations....
Focusing on the «pause» is mainly significant in context of the comparison
between climate model
projections and surface
temperatures.
The real issue is the growing divergence
between climate model
projections and the surface
temperature observations, illustrated in this diagram by Ed Hawkins:
Despite the poor match
between projections from global climate models and U.S. continental
temperature trends, the paper (in Figure 12) reveals an interesting pattern.
For regional climate predictability, the added value of RCMs should come from better resolving the relationship
between mean (
temperature) trends and key indicators that are supposedly better represented in the high resolution
projections utilizing additional local information, such as
temperature or precipitation extremes.
Since IPCC's first report in 1990, assessed
projections have suggested global average
temperature increases [at least, because of IPCC's accelerated warming claim]
between about 0.15 °C and 0.3 °C per decade for 1995 to 2010.
To a naïve observer of
temperatures, the difference of
temperature between day and night would lead the observer to make extreme
projections for the very near future.
Claim of a substantial gap
between model
projections for global
temperature & observations is not true (updated with 2017 estimate): pic.twitter.com/YHzzXtbhs 9
To a more informed observer, the differences of
temperature between summer and winter would lead to equally extreme, but merely more distant
projections.
Based on our inferred close relationship
between past and future
temperature evolution, our study suggests that paleo - climatic data can help to reduce uncertainty in future climate
projections.
The discrepancy
between recent observed and simulated trends in global mean surface
temperature has provoked a debate about possible causes and implications for future climate change
projections.
This point was also made by Schmidt et al. (2014), which additionally showed that incorporating the most recent estimates of aerosol, solar, and greenhouse gas forcings, as well as the El Niño Southern Oscillation (ENSO) and
temperature measurement biases, the discrepancy
between average GCM global surface warming
projections and observations is significantly reduced.
I'm afraid that much of the strength of the reaction to your questions was based on past experiences - I can not count how many times someone has commented here and on other climate blogs claiming despite the evidence that mismatches
between specific
projections and observed
temperatures somehow invalidate all climate modeling, despite the projected emissions not matching actuals.
And now — based on sea level behavior
between 1930 and 2010, as derived from United States tide gauge data, plus extensions of previous global - gauge analyses — a new empirical study, which does not rely on a relationship
between sea level and
temperature, casts doubt upon both sets of
projections.
Activity
between 2019 and 2020 will focus on expanding the hydrologic
projections and water
temperature modelling into additional basins and completing an analysis of regional changes in hydrologic extremes.
Between Watts» and your work it is getting really hard to believe any
temperature projections from the historical datasets.
The consequences for models» predictions of the future
temperature can be seen in Figure 4, which shows that the mesoscale model's
projections of mean maximum summertime
temperatures over the eastern US for July 2085 soar into the 95 - 110 °F range, while the corresponding predictions for the GCM range
between 75 - 95 °F.
It looks like some sort of hybrid
between AR4
projections for tropical sea
temperature increase and global average surface
temperature rise.
it is found that global
temperature trends since 1998 are consistent with internal variability overlying the forced trends seen in climate model
projections (Easterling and Wehner, 2009; Mitchell et al., 2012b); see also Figure 1.1, where differences
between the observed and multimodel response of comparable duration occurred earlier.
While it is difficult to distinguish
between the recent slow - down in global surface
temperatures and the underlying long - term trend, the slow - down stands out much more vividly when compared to
projections from the latest set of GCMs.
Even the MSM has discussed the divergence
between temperature data and model
projections.
In a similar analysis to that of Räisänen [13], the correlation
between the
temperature change and the modelled preindustrial mean
temperature for all
projections was calculated.
James, the IPCC
projections for 2050 suggest that the
temperature rise will be
between 1.2 and 1.9 degrees.
Since IPCC's first report in 1990, assessed
projections have suggested global average
temperature increases
between about 0.15 °C and 0.3 °C per decade for 1990 to 2005.
First, as you can clearly see in the figure «'' the actual observed runnning average
temperatures from the Hadley Center since 1995 have been
between the IPCC scenario
projection and Dr. Keenlyside's forecast, which does suggest that his model may be underestimating warming.