I mainly study responses of tropical low - clouds to perturbations since they induce
the largest uncertainties in climate models and explain a significant part of the spread of climate sensitivity.
Not exact matches
Some of the
largest uncertainties in current
climate models stem from their wide - ranging estimates of the size and number of dust particles
in the atmosphere.
Therefore, Caldeira said, the more important question - and one of the
largest sources of
uncertainty in climate models - is «will the end of oil usher
in a century of coal, or will it usher
in a transition toward low - carbon - emitting technologies?»
Mission leaders were relieved and eager to begin their studies of cloud and haze effects, which «constitute the
largest uncertainties in our
models of future
climate — that's no exaggeration,» says Jens Redemann, an atmospheric scientist at NASA's Ames Research Center
in Mountain View, California, and the principal investigator for ObseRvations of Aerosols above CLouds and their IntEractionS (ORACLES).
Its behaviour looks like what happens
in the real world, but Erickson stresses that «the
uncertainties remain
large», and that much more work needs to be done before such
models can be used to predict future
climate trends.
Clouds also are the
largest source of
uncertainty in present
climate models, according to the latest report of the Intergovernmental Panel on Climate
climate models, according to the latest report of the Intergovernmental Panel on
Climate Climate Change.
By 2100, the choice of driving
climate model conditions dominates the
uncertainty, but by 2200, the
uncertainty in the ice sheet
model and the elevation scheme are
larger.
A new integrated
climate model developed by Oak Ridge National Laboratory and other institutions is designed to reduce
uncertainties in future
climate predictions as it bridges Earth systems with energy and economic
models and
large - scale human impact data.
A new integrated computational
climate model developed to reduce
uncertainties in future
climate predictions marks the first successful attempt to bridge Earth systems with energy and economic
models and
large - scale human impact data.
But while Lewis argues that the
uncertainty in E is
large and
climate models do not give the value as accurately as we'd like, that does not justify ignoring that
uncertainty entirely.
One of the
largest uncertainties in global
climate models (GCMs) is the response of clouds
in a warming world.
Murphy, J.M., et al., 2004: Quantification of
modelling uncertainties in a
large ensemble of
climate change simulations.
But it leaves a
large uncertainty in the timing; more complex coupled ice - sheet and
climate models are needed to
model this more thoroughly
in the future.
M2009 use a simplified carbon cycle and
climate model to make a
large ensemble of simulations
in which principal
uncertainties in the carbon cycle, radiative forcings, and
climate response are allowed to vary, thus yielding a probability distribution for global warming as a function of time throughout the 21st century.
The
model results (which are based on driving various
climate models with estimated solar, volcanic, and anthropogenic radiative forcing changes over this timeframe) are, by
in large, remarkably consistent with the reconstructions, taking into account the statistical
uncertainties.
The work of Schmittner et al. demonstrates that
climates of the past can provide potentially powerful information to reduce
uncertainty in future
climate predictions and evaluate the likelihood of
climate change that is
larger than captured
in present
models.
A new
large uncertainty analysis that appeared this week
in Nature shows that it is very difficult to get a
climate sensitivity below 2 ºC
in a
climate model, no matter how one changes the parameters.
«This introduces a
large uncertainty in the degree of warming predicted by
climate change
models.»
The
largest source of
uncertainty in today's
climate models is clouds.
I am talking about a consensus of multiple lines of evidence (empirical evidence
in addition to
modeling, logic etc.) When there is a
large degree of
uncertainty, as there is
in climate science, a consensus of evidence is most definitely very important.
And since CG2 I've just been more attuned to the
large and deep
uncertainties in all of
climate science, especially the
models.
Climate models project decreases of renewable water resources
in some regions and increases
in others, albeit with
large uncertainty in many places.
While there is still some degree of
uncertainty in all these components, the
largest source of
uncertainty in today's
climate models are clouds.
This
large spread
in the predictions reflects the current diversity
in the formulation of physics and initial conditions
in the various
models used, but also inherent
uncertainty of the
climate system.
However, even state - of - the - art
climate models (GCMs) have systematic errors
in simulation of different
climate characteristics, which are often much
larger than observations
uncertainties (Covey et al. 2003).
M2009 use a simplified carbon cycle and
climate model to make a
large ensemble of simulations
in which principal
uncertainties in the carbon cycle, radiative forcings, and
climate response are allowed to vary, thus yielding a probability distribution for global warming as a function of time throughout the 21st century.
However, there remains
uncertainty in the rate of sea ice loss, with the models that most accurately project historical sea ice trends currently suggesting nearly ice - free conditions sometime between 2021 and 2043 (median 2035).12 Uncertainty across all models stems from a combination of large differences in projections among different climate models, natural climate variability, and uncertainty about future rates of fossil fuel
uncertainty in the rate of sea ice loss, with the
models that most accurately project historical sea ice trends currently suggesting nearly ice - free conditions sometime between 2021 and 2043 (median 2035).12
Uncertainty across all models stems from a combination of large differences in projections among different climate models, natural climate variability, and uncertainty about future rates of fossil fuel
Uncertainty across all
models stems from a combination of
large differences
in projections among different
climate models, natural
climate variability, and
uncertainty about future rates of fossil fuel
uncertainty about future rates of fossil fuel emissions.
But accepting the
climate models as our currently best representation of the
climate system, the observations unmistakably point to higher ECS being more likely, and a substantially higher ECS than previously thought as most likely — though the range of possible ECS obtained
in this way is still wide, still indicating
large uncertainties.
and «no data or computer code appears to be archived
in relation to the paper» and «the sensitivity of Shindell's TCR estimate to the aerosol forcing bias adjustment is such that the true
uncertainty of Shindell's TCR range must be huge — so
large as to make his estimate worthless» and the seemingly arbitrary to cherry picked
climate models used
in Shindell's analysis.
The very high significance levels of
model — observation discrepancies
in LT and MT trends that were obtained
in some studies (e.g., Douglass et al., 2008; McKitrick et al., 2010) thus arose to a substantial degree from using the standard error of the
model ensemble mean as a measure of
uncertainty, instead of the ensemble standard deviation or some other appropriate measure for
uncertainty arising from internal
climate variability... Nevertheless, almost all
model ensemble members show a warming trend
in both LT and MT
larger than observational estimates (McKitrick et al., 2010; Po - Chedley and Fu, 2012; Santer et al., 2013).
Decadal
climate prediction is immature, and
uncertainties in future forcings,
model responses to forcings, or initialisation shocks could easily cause
large errors
in forecasts.
They are perhaps the
largest uncertainty in our understanding of
climate change, owing to disagreement among
climate models and observational datasets over what cloud changes have occurred during recent decades and will occur
in response to global warming2, 3.
It is well recognized that our inability to accurately simulate clouds
in computer
models is the
largest uncertainty in climate change projections.
Although the most advanced theoretical
climate models still leave
uncertainty, particularly about the sign and magnitudes of the effects, on GHG feedbacks, of some low - and high - clouds, a consensus began to develop that threats of resulting increases
in global temperature — and the very
large risks associated with their possible consequences — deserved substantial increase
in attention.
Other researchers uncovered
large uncertainties in climate predictions made by the fifth phase of the Coupled
Model Intercomparison Project (CMIP5), a widely used, multimodel tool for
climate analysis.