Sentences with phrase «in equilibrium sensitivity»

No change in the equilibrium sensitivity to 2X CO2, but the transient response could be pretty rough.

Not exact matches

Specifically, the draft report says that «equilibrium climate sensitivity» (ECS)-- eventual warming induced by a doubling of carbon dioxide in the atmosphere, which takes hundreds of years to occur — is «extremely likely» to be above 1 degree Celsius (1.8 degrees Fahrenheit), «likely» to be above 1.5 degrees Celsius (2.4 degrees Fahrenheit) and «very likely» to be below 6 degrees Celsius (10.8 Fahrenheit).

The «equilibrium» sensitivity of the global surface temperature to solar irradiance variations, which is calculated simply by dividing the absolute temperature on the earth's surface (288K) by the solar constant (1365Wm - 2), is based on the assumption that the climate response is linear in the whole temperature band starting at the zero point.

We show elsewhere (8) that a forcing of 1.08 W / m2 yields a warming of 3/4 °C by 2050 in transient climate simulations with a model having equilibrium sensitivity of 3/4 °C per W / m2.

Where (equilibrium / effective) climate sensitivity (S) is the only parameter being estimated, and the estimation method works directly from the observed variables (e.g., by regression, as in Forster and Gregory, 2006, or mean estimation, as in Gregory et al, 2002) over the instrumental period, then the JP for S will be almost of the form 1 / S ^ 2.

Given that it doesn't matter much which forcing is changing, sensitivity can be assessed from any particular period in the past where the changes in forcing are known and the corresponding equilibrium temperature change can be estimated.

Beyond equilibrium climate sensitivity -LSB-...] Newer metrics relating global warming directly to the total emitted CO2 show that in order to keep warming to within 2 °C, future CO2 emissions have to remain strongly limited, irrespective of climate sensitivity being at the high or low end.»

So we don't really know the temperature lag or how the temperature is supposed to behave until equilibrium, and the sensitivity will be difficult to confirm by direct observation (say, in our lifetime)?

Here's an interesting paper that is referenced in some of the listed publications: Meraner et al. 2013, Robust increase in equilibrium climate sensitivity under global warming, GRL https://hal.inria.fr/hal-01099395/document

There have been quite a number of papers published in recent years concerning «emergent constraints» on equilibrium climate sensitivity (ECS) in comprehensive global climate models (GCMs), of both the current (CMIP5) and previous (CMIP3) generations.

It is worth adding though, that temperature trends over the next few decades are more likely to be correlated to the TCR, rather than the equilibrium sensitivity, so if one is interested in the near - term implications of this debate, the constraints on TCR are going to be more important.

Chris Colose @ 39 — Thanks as always, but I am baffled by your The larger thermal inertia of the ocean is important, but the higher sensitivity over land than in the ocean is also seen in equilibrium simulations when the ocean has had time to «catch up,» so that argument doesn't hold as equilibrium is approached.

In Part 1 of this article the nature and validity of emergent constraints [1] on equilibrium climate sensitivity (ECS) in GCMs were discussed, drawing mainly on the analysis and assessment of 19 such constraints in Caldwell et al. (2018), [2] who concluded that only four of them were crediblIn Part 1 of this article the nature and validity of emergent constraints [1] on equilibrium climate sensitivity (ECS) in GCMs were discussed, drawing mainly on the analysis and assessment of 19 such constraints in Caldwell et al. (2018), [2] who concluded that only four of them were crediblin GCMs were discussed, drawing mainly on the analysis and assessment of 19 such constraints in Caldwell et al. (2018), [2] who concluded that only four of them were crediblin Caldwell et al. (2018), [2] who concluded that only four of them were credible.

And further, in stating the year 2100 values, you are mixing up transient with equilibrium climate sensitivity.

In Part 1 of this article the nature and validity of emergent constraints [i] on equilibrium climate sensitivity (ECS) in GCMs were discussed, drawing mainly on the analysis and assessment of 19 such constraints in Caldwell et al (2018; henceforth Caldwell), [ii] who concluded that only four of them were crediblIn Part 1 of this article the nature and validity of emergent constraints [i] on equilibrium climate sensitivity (ECS) in GCMs were discussed, drawing mainly on the analysis and assessment of 19 such constraints in Caldwell et al (2018; henceforth Caldwell), [ii] who concluded that only four of them were crediblin GCMs were discussed, drawing mainly on the analysis and assessment of 19 such constraints in Caldwell et al (2018; henceforth Caldwell), [ii] who concluded that only four of them were crediblin Caldwell et al (2018; henceforth Caldwell), [ii] who concluded that only four of them were credible.

They conclude, based on study of CMIP5 model output, that equilibrium climate sensitivity (ECS) is not a fixed quantity — as temperatures increase, the response is nonlinear, with a smaller effective ECS in the first decades of the experiments, increasing over time.

Then on page 9.5 we read «There is very high confidence that the primary factor contributing to the spread in equilibrium climate sensitivity continues to be the cloud feedback.

First let's define the «equilibrium climate sensitivity» as the «equilibrium change in global mean surface temperature following a doubling of the atmospheric (equivalent) CO2 concentration.

ACT - activated clotting time (bleeding disorders) ACTH - adrenocorticotropic hormone (adrenal gland function) Ag - antigen test for proteins specific to a disease causing organism or virus Alb - albumin (liver, kidney and intestinal disorders) Alk - Phos, ALP alkaline phosphatase (liver and adrenal disorders) Allergy Testing intradermal or blood antibody test for allergen hypersensitivity ALT - alanine aminotransferase (liver disorder) Amyl - amylase enzyme — non specific (pancreatitis) ANA - antinuclear antibody (systemic lupus erythematosus) Anaplasmosis Anaplasma spp. (tick - borne rickettsial disease) APTT - activated partial thromboplastin time (blood clotting ability) AST - aspartate aminotransferase (muscle and liver disorders) Band band cell — type of white blood cell Baso basophil — type of white blood cell Bile Acids digestive acids produced in the liver and stored in the gall bladder (liver function) Bili bilirubin (bile pigment responsible for jaundice from liver disease or RBC destruction) BP - blood pressure measurement BUN - blood urea nitrogen (kidney and liver function) Bx biopsy C & S aerobic / anaerobic bacterial culture and antibiotic sensitivity test (infection, drug selection) Ca +2 calcium ion — unbound calcium (parathyroid gland function) CBC - complete blood count (all circulating cells) Chol cholesterol (liver, thyroid disorders) CK, CPK creatine [phospho] kinase (muscle disease, heart disease) Cl - chloride ion — unbound chloride (hydration, blood pH) CO2 - carbon dioxide (blood pH) Contrast Radiograph x-ray image using injected radiopaque contrast media Cortisol hormone produced by the adrenal glands (adrenal gland function) Coomb's anti- red blood cell antibody test (immune - mediated hemolytic anemia) Crea creatinine (kidney function) CRT - capillary refill time (blood pressure, tissue perfusion) DTM - dermatophyte test medium (ringworm — dermatophytosis) EEG - electroencephalogram (brain function, epilepsy) Ehrlichia Ehrlichia spp. (tick - borne rickettsial disease) EKG, ECG - electrok [c] ardiogram (electrical heart activity, heart arryhthmia) Eos eosinophil — type of white blood cell Fecal, flotation, direct intestinal parasite exam FeLV Feline Leukemia Virus test FIA Feline Infectious Anemia: aka Feline Hemotrophic Mycoplasma, Haemobartonella felis test FIV Feline Immunodeficiency Virus test Fluorescein Stain fluorescein stain uptake of cornea (corneal ulceration) fT4, fT4ed, freeT4ed thyroxine hormone unbound by protein measured by equilibrium dialysis (thyroid function) GGT gamma - glutamyltranferase (liver disorders) Glob globulin (liver, immune system) Glu blood or urine glucose (diabetes mellitus) Gran granulocytes — subgroup of white blood cells Hb, Hgb hemoglobin — iron rich protein bound to red blood cells that carries oxygen (anemia, red cell mass) HCO3 - bicarbonate ion (blood pH) HCT, PCV, MHCT hematocrit, packed - cell volume, microhematocrit (hemoconcentration, dehydration, anemia) K + potassium ion — unbound potassium (kidney disorders, adrenal gland disorders) Lipa lipase enzyme — non specific (pancreatitis) LYME Borrelia spp. (tick - borne rickettsial disease) Lymph lymphocyte — type of white blood cell MCHC mean corpuscular hemoglobin concentration (anemia, iron deficiency) MCV mean corpuscular volume — average red cell size (anemia, iron deficiency) Mg +2 magnesium ion — unbound magnesium (diabetes, parathyroid function, malnutrition) MHCT, HCT, PCV microhematocrit, hematocrit, packed - cell volume (hemoconcentration, dehydration, anemia) MIC minimum inhibitory concentration — part of the C&S that determines antimicrobial selection Mono monocyte — type of white blood cell MRI magnetic resonance imaging (advanced tissue imaging) Na + sodium ion — unbound sodium (dehydration, adrenal gland disease) nRBC nucleated red blood cell — immature red blood cell (bone marrow damage, lead toxicity) PCV, HCT, MHCT packed - cell volume, hematocrit, microhematocrit (hemoconcentration, dehydration, anemia) PE physical examination pH urine pH (urinary tract infection, urolithiasis) Phos phosphorus (kidney disorders, ketoacidosis, parathyroid function) PLI pancreatic lipase immunoreactivity (pancreatitis) PLT platelet — cells involved in clotting (bleeding disorders) PT prothrombin time (bleeding disorders) PTH parathyroid hormone, parathormone (parathyroid function) Radiograph x-ray image RBC red blood cell count (anemia) REL Rocky Mountain Spotted Fever / Ehrlichia / Lyme combination test Retic reticulocyte — immature red blood cell (regenerative vs. non-regenerative anemia) RMSF Rocky Mountain Spotted Fever SAP serum alkaline phosphatase (liver disorders) Schirmer Tear Test tear production test (keratoconjunctivitis sicca — dry eye,) Seg segmented neutrophil — type of white blood cell USG Urine specific gravity (urine concentration, kidney function) spec cPL specific canine pancreatic lipase (pancreatitis)-- replaces the PLI test spec fPL specific feline pancreatic lipase (pancreatitis)-- replaces the PLI test T4 thyroxine hormone — total (thyroid gland function) TLI trypsin - like immunoreactivity (exocrine pancreatic insufficiency) TP total protein (hydration, liver disorders) TPR temperature / pulse / respirations (physical exam vital signs) Trig triglycerides (fat metabolism, liver disorders) TSH thyroid stimulating hormone (thyroid gland function) UA urinalysis (kidney function, urinary tract infection, diabetes) Urine Cortisol - Crea Ratio urine cortisol - creatine ratio (screening test for adrenal gland disease) Urine Protein - Crea Ratio urine protein - creatinine ratio (kidney disorders) VWF VonWillebrands factor (bleeding disorder) WBC white blood cell count (infection, inflammation, bone marrow suppression)

Given that it doesn't matter much which forcing is changing, sensitivity can be assessed from any particular period in the past where the changes in forcing are known and the corresponding equilibrium temperature change can be estimated.

ignoring the energy cost of water and latent heat transport [in the hydrologic cycle] leads to equilibrium calculations overestimating the climate sensitivity)...

A few things are unequivocal, perhaps (doubling from the present concentration of CO2 will take 140 years [give or take]; the idea that the changes in climate since 1880 have been in the aggregate beneficial; it takes more energy to vaporize a kg of water than to raise its temperature by 1K; ignoring the energy cost of water and latent heat transport [in the hydrologic cycle] leads to equilibrium calculations overestimating the climate sensitivity), but most are propositions that I think need more research, but can't be refuted on present evidence.

We show elsewhere (8) that a forcing of 1.08 W / m2 yields a warming of 3/4 °C by 2050 in transient climate simulations with a model having equilibrium sensitivity of 3/4 °C per W / m2.

While I'm posting (I can see how you guys get into this) I'm also very uncomfortable with your notion of «tacit knowledge:» it certainly seems to be tacit knowledge in the blogosphere that the chances of the climate sensitivity (equilibrium warming on indefinite stabilization at 560ppm CO2, for the non-enthusiasts) being greater than or equal to 6 degrees are too small to be worth worrying about (meaning down at the level of an asteroid strike).

You can not use equilibrium climate sensitivity to estimate the response to an 11 year periodic forcing — precisely because it is not in equilibirum!

Andrew (23) and Bryan (35): The problem is that climate sensitivity and thermal inertia could be traded off mathematically in producing a decent match with the observed temeperature record of the 20th century (because it's out of equilibrium.

It's unlikely that the greenhouse gas contribution in the period 1880 - 1940 was nearly 0.3 oC since that would be the full equilibrium response (under a 3 oC climate sensitivity).

At the low end of sensitivity, we are living in a period of over reaction by the climate and the rate of warming should tend to revert lower towards the equilibrium value.

Your attempt to estimate equilibrium climate sensitivity from the 20th C won't work because a) the forcings are not that well known (so the error in your estimate is large), b) the climate is not in equilibrium — you need to account for the uptake of heat in the ocean at least.

I didn't know that data since 1850 as summarized is essentially useless for estimating climate sensitivity given that the Earth's radiative heat exchange is not in equilibrium over that period.

We climatologists describe this in terms of the climate sensitivity, the warming that results in equilibrium from a doubling of CO2.

In the interview he mentioned the 11 degrees bit and we chatted for a while about how that was a very long term figure (such a climate sensitivity would require a very long time to come into equilibrium) and how we gave no odds at all of that being the case.

One would think that these huge historical variations are rather signs of a system that is very far from equilibrium, in which case the usual «sensitivity» technique is not adequate and may be misleading.

Global temperature change is about half that in Antarctica, so this equilibrium global climate sensitivity is 1.5 C (Wm ^ -2) ^ -1, double the fast - feedback (Charney) sensitivity.

«Sensitivity» means the total equilibrium rise in temperature due to doubling CO2.

Nevertheless, climate sensitivity is part of the puzzle, and it particularly matters if you are interested in stabilisation scenarios, since it indicates what a particular equilibrium CO2 level will mean for equilibrium climate.

It is worth adding though, that temperature trends over the next few decades are more likely to be correlated to the TCR, rather than the equilibrium sensitivity, so if one is interested in the near - term implications of this debate, the constraints on TCR are going to be more important.

The problems with associating sensitivity with a temperature in 2100 are twofold: first, at the time we reach CO2 doubling, the temperature will lag behind the equilibrium value due to thermal inertia, especially in the ocean (thought experiment — doubling CO2 today will not cause an instant 3C jump in temperatures, any more than turning your oven on heats it instantly to 450F), and secondly, the CO2 level we are at in 2100 depends on what we do between now and then anyway, and it may more than double, or not.

The true equilibrium climate sensitivity for the climate models used in this demonstration is in the range 2.1 — 4.4, and the transient climate sensitivity is 1.2 — 2.6 (IPCC AR5, Table 8.2).

The approximately 20 - year lag (between atmospheric CO2 concentration change and reaching equilibrium temperature) is an emerging property (just like sensitivity) of the global climate system in the GCM models used in the paper I linked to above, if I understood it correctly.

Maybe the word «equilibrium» should be omitted from all climate sensitivity estimates, from the shortest term values (TCR) to the longest and most comprehensive (Earth System), since all the different forms of sensitivity estimation seem, in my view, to be looking at somewhat different phenomena and should not necessarily yield the same values.

I never asserted that sensitivity in terms of equilibrium time - average surface temperature change per unit change in TOA or even tropopause - level forcing (with or without stratospheric adjustment) would be the same for each type of forcing for each climatic state and the external forcings that maintain it (or for that matter, for each of those different of forcings (TOA vs tropopause, etc.) with everything held constant.

If it is correct, then the term Equilibrium Climate Sensitivity would surely be a misnomer, in that no predictable equilibrium iEquilibrium Climate Sensitivity would surely be a misnomer, in that no predictable equilibrium iequilibrium is achieved.

Hegerl et al (2006) for example used comparisons during the pre-industrial of EBM simulations and proxy temperature reconstructions based entirely or partially on tree - ring data to estimate the equilibrium 2xCO2 climate sensitivity, arguing for a substantially lower 5 % -95 % range of 1.5 — 6.2 C than found in several previous studies.

In this case the CO2 concentration is instantaneously quadrupled and kept constant for 150 years of simulation, and both equilibrium climate sensitivity and RF are diagnosed from a linear fit of perturbations in global mean surface temperature to the instantaneous radiative imbalance at the TOIn this case the CO2 concentration is instantaneously quadrupled and kept constant for 150 years of simulation, and both equilibrium climate sensitivity and RF are diagnosed from a linear fit of perturbations in global mean surface temperature to the instantaneous radiative imbalance at the TOin global mean surface temperature to the instantaneous radiative imbalance at the TOA.

What could hypothetically happen if a very large change in GHG amount / type is made, is that the forcing could increase beyond a point where it becomes saturated at the tropopause level at all wavelengths — what can happen then is that the equilibrium climate sensitivity to the nearly zero forcing from additional GHGs may approach infinity, because in equilibrium the tropopause has to shift upward enough to reach a level where there can be some net LW flux up through it.

One can consider net PR+CR as a response to externally - imposed RF (external forcing) plus feedback «RF», or one can consider PR + CR — feedback «RF» as the response to the externally imposed RF; the later is perhaps more helpful in picturing the time evolution toward equilibrium (and illustrates why the time it takes for an imbalance, equal to: externally imposed RF — climate dependent terms (PR + CR — feedback «RF»), to decay is proportional to both heat capacity and climate sensitivity (defined per unit externally imposed RF).

The feedback can become zero — or to avoid confusion regarding what is and is not a feedback — the equilibrium climate sensitivity can become infinite (or negative) in some conditions.

In fact, if the physics - based understanding of «equilibrium sensitivity» to any forcing is too low, then not only will CO2 have a greater effect, so too will all other forcings, such as: changes in the sun, in cloud cover, in albedo, etcIn fact, if the physics - based understanding of «equilibrium sensitivity» to any forcing is too low, then not only will CO2 have a greater effect, so too will all other forcings, such as: changes in the sun, in cloud cover, in albedo, etcin the sun, in cloud cover, in albedo, etcin cloud cover, in albedo, etcin albedo, etc..

Also in the paper the sensitivity resulting from the models appears to be about 2/3 deg C per W / m2, so if we maintain the current level of forcing indefinitely, this suggests the time delay before equilibrium is established is as follows