«For example,
the best global atmospheric models driven by specified sea surface temperatures can do a good job of simulating global temperature, winds and water vapor distributions.
Not exact matches
They used the Community Earth System
Model, funded primarily by the Department of Energy and NSF, to simulate
global climate as
well as
atmospheric chemistry conditions.
The work is an estimate of the
global average based on a single - column, time - average
model of the atmosphere and surface (with some approximations — e.g. the surface is not truly a perfect blackbody in the LW (long - wave) portion of the spectrum (the wavelengths dominated by terrestrial /
atmospheric emission, as opposed to SW radiation, dominated by solar radiation), but it can give you a pretty
good idea of things (fig 1 shows a spectrum of radiation to space); there is also some comparison to actual measurements.
Back in
atmospheric physics, chaotic behaviour is a highly - studied and
well - understood phenomenon of all realistic
global models, arising directly from the nonlinearity of the Navier - Stokes equations for fluid flow.
It is not difficult to calculate the actual potential intensity from SST and
atmospheric soundings, and this can be done as
well for reanalysis and
global model data sets.
To
better determine the fate of the species in the face of climate change, the researchers analyzed a total of 34 different
global climate
models, taking into account
atmospheric sensitivity to greenhouse gases and different levels of human greenhouse gas emissions.
However, because climate scientists at the time believed a doubling of
atmospheric CO2 would cause a larger
global heat imbalance than today's estimates, the actual climate sensitivities were approximatly 18 % lower (for example, the «
Best»
model sensitivity was actually closer to 2.1 °C for doubled CO2).
However, as in the FAR, because climate scientists at the time believed a doubling of
atmospheric CO2 would cause a larger
global heat imbalance than current estimates, the actual «
best estimate»
model sensitivity was closer to 2.1 °C for doubled CO2.
As shown in Figure 2, the IPCC FAR ran simulations using
models with climate sensitivities (the total amount of
global surface warming in response to a doubling of
atmospheric CO2, including amplifying and dampening feedbacks) correspoding to 1.5 °C (low), 2.5 °C (
best), and 4.5 °C (high).
The direct radiative forcing calculation is based on an empiric al equation derived from
well - established
atmospheric radiative energy transfer
models and serves as a first - order proxy for
global warming impact.»
''... had the IPCC FAR correctly projected the changes in
atmospheric GHG from 1990 to 2011, their «
best estimate»
model with a 2.5 °C equilibrium climate sensitivity would have projected the ensuing
global warming very accurately»
The IPCC FAR ran simulations using
models with climate sensitivities (the total amount of
global surface warming in response to a doubling of
atmospheric CO2, including amplifying and dampening feedbacks) of 1.5 °C (low), 2.5 °C (
best), and 4.5 °C (high) for doubled CO2 (Figure 1).
However, because climate scientists at the time believed a doubling of
atmospheric CO2 would cause a larger
global heat imbalance than is currently believed, the actual climate sensitivities were approximatly 18 % lower (for example, the «
Best»
model sensitivity was actually closer to 2.1 °C for doubled CO2).
In a paper on the Energy & Environmental Science web site (17/7/12), meteorologist John Ten Hoeve and environmental engineer Mark Jacobson, both at Stanford University in California have calculated that, based on estimates of the radioactive nuclides released at Fukuhima, a three - dimensional
global atmospheric model for radioactive fallout patterns and the linear no - threshold (LNT)
model for resultant cancers, there would be between 15 and 1100 linked cancer deaths, with their
best estimate being 130 deaths.
Motivated by findings that major components of so - called cloud «feedbacks» are
best understood as rapid responses to CO2 forcing (Gregory and Webb in J Clim 21:58 — 71, 2008), the top of atmosphere (TOA) radiative effects from forcing, and the subsequent responses to
global surface temperature changes from all «
atmospheric feedbacks» (water vapour, lapse rate, surface albedo, «surface temperature» and cloud) are examined in detail in a General Circulation
Model.
The bottom line from the new report from the
Global Warming Policy Foundation (GWPF) is that the U.N.'s Intergovernmental Panel on Climate Change (IPCC) knew, but didn't highlight, the fact that the best available scientific evidence suggests that the earth's climate is much less sensitive to atmospheric carbon dioxide input than the climate models they relied upon to forecast future global warming po
Global Warming Policy Foundation (GWPF) is that the U.N.'s Intergovernmental Panel on Climate Change (IPCC) knew, but didn't highlight, the fact that the
best available scientific evidence suggests that the earth's climate is much less sensitive to
atmospheric carbon dioxide input than the climate
models they relied upon to forecast future
global warming po
global warming portray.
Additionally, the climate sensitivity in Hansen's 1988
model (4.2 °C
global warming for a doubling of
atmospheric CO2) was a bit higher than today's
best estimate (3 °C warming for CO2 doubling).
The current generation of
global atmospheric models in use for climate studies around the world do some things remarkably
well, as I've tried to argue in several earlier posts.