Climatologists would have dearly loved to
narrow the uncertainty range of climate sensitivity, but until recently there has been not enough solid evidence to justify this.
We shall see in this 3 - part article that emergent constraint approaches have the potential to offer useful insights into cloud behaviour, however the main focus will be on to what extent
they narrow the uncertainty range of ECS in GCMs.
Climatologists would have dearly loved to
narrow the uncertainty range of climate sensitivity, but until recently there has been not enough solid evidence to justify this.
Scientists have found it hard to
narrow the uncertainty range on ECS: at a conference in Bavaria in March we looked at evidence that suggested values from one to six degrees or even more.
We shall see in this 3 - part article that emergent constraint approaches have the potential to offer useful insights into cloud behaviour, however the main focus will be on to what extent
they narrow the uncertainty range of ECS in GCMs.
Not exact matches
That's about as
narrow a
range of
uncertainty as the market ever creates.
The study could help
narrow the
range of
uncertainty around how climate change is expected to alter California's precipitation patterns.
In isolation, a
narrow range bar signals
uncertainty while a wide
range bar shows wild trading.
Throw in the unemployment rate (as a measure of buyer
uncertainty) and the and the
range narrows further.
The
ranges are
narrower than in the TAR mainly because of improved information about some
uncertainties in the projected contributions15.
While Annan and Hargreaves gave an upper limit (at 5 %) of 4.5 C, Annan suggests that this is actually being generous with the
uncertainty in his blog — not that this matters so much until the technical paper comes out which demonstrates a
narrower range.
Pressing the frontiers of climate science and related research is vital, but it's wishful thinking to expect further science to substantially
narrow uncertainties on time scales that matter when it comes to regional or short - term climate forecasting, the
range of possible warming from a big buildup of carbon dioxide, the impact of greenhouse forcing on rare extremes and the like.
Steven E. Koonin, once the Obama administration's undersecretary of energy for science and chief scientist at BP, stirred up a swirl of turbulence in global warming discourse this week after The Wall Street Journal published «Climate Science is Not Settled,» his essay calling for more frankness about areas of deep
uncertainty in climate science, more research to
narrow error
ranges and more acknowledgement that society's decisions on energy and climate policy are based on values as much as data.
As already noted, my iRF efficacy
uncertainty ranges are much
narrower than Marvel et al.'s.
Without being able to properly
narrow those
ranges of
uncertainty, CO2 has to be the problem.
So, recent research is
narrowing the
range of
uncertainty of the aci, and overall reducing the magnitude of the aci effect.
Complexity of the climate system and
uncertainty surrounding input data preclude extremely accurate predictions, but they are not incompatible with an ability to approximate real world outcomes within a
range narrow enough to justify future planning on the basis of reasonable probabilities.
If you can't
narrow it down because of the
uncertainties, you supply a
range from best case to worse case and let the pollies decide what is acceptable — that's their job, right?
The hope is that new research can help
narrow the
range of
uncertainty.
In fairness, there remains considerable
uncertainty in aerosol effects, but if there will be real progress in
narrowing the credible
range for climate sensitivity, it has to come from reducing the still too wide
uncertainty in aerosol effects, not from flogging climate models which assume aerosol offsets inconsistent with the best available measured effects.
The outcome is relatively predictable, with a
narrow range of
uncertainty.
The problem seems to be that even during that time, the 2 - 4.5 C estimated
range hasn't
narrowed much, and so the same level of
uncertainty prevails.
Thus the
uncertainty in sensitivity itself argues for insurance against high sensitivity, and
narrowing down the
range (and particularly excluding the higher end) could significantly change our optimal policy response.»
While different researchers have different best estimates (James Annan, for example, says his best estimate is 2.5 C),
uncertainties still mean that estimates can not be
narrowed down to a far
narrower and more precise
range.
The quartiles for July are 4.2 and 4.7 million square kilometers, a rather
narrow range given that the
uncertainty of individual estimates are on the order of 0.5 million square kilometers.
Zhai makes much less allowance for
uncertainty than does Brient Alb, hence its
narrow constrained ECS
range.
For two decades, those estimates have run from 1.5 C to 5C, a wide
range; the new research
narrowed that
range to between 3C and 5C, by closely examining the biggest cause of
uncertainty: clouds.