Since all models significantly expand their Hadley cells in
climate warming simulations, this cloud - circulation interaction leaves a significant imprint on the radiative impact of the clouds.
Not exact matches
In the Department of Meteorology at Stockholm University (MISU), researchers have done a series of model
simulations investigating tropical cyclone activity during an earlier
warm climate, the mid-Holocene, 6,000 years ago.
«Weather should remain predictable despite
climate change:
Simulations of jet stream behavior in a
warming climate suggest ranges of forecasts in the mid-century will be similar to those in present day.»
We've narrowed the uncertainty in surface
warming projections by generating thousands of
climate simulations that each closely match observational records for nine key
climate metrics, including
warming and ocean heat content.»
They are using the
simulation, detailed in a new paper in Royal Society Open Science, to determine how drought,
warmer weather, more frequent wildfires and other
climate - related changes will affect forests across North America.
Likewise, while models can not represent the
climate system perfectly (thus the uncertainly in how much the Earth will
warm for a given amount of emissions),
climate simulations are checked and re-checked against real - world observations and are an established tool in understanding the atmosphere.
Dr Stephen Grimes of Plymouth University, who initiated the research project, highlighted the
climate changes that must have caused this increase in sediment erosion and transport — «We have
climate model
simulations of the effect of
warming on rainfall during the PETM event, and they show some changes in the average amounts of rainfall, but the largest change is how this rainfall is packaged up — it's concentrated in more rapid, extreme events — larger and bigger storms.»
Climate simulations suggest that that upwelling has generally cooled Earth's climate, stifling about 0.1 °C to 0.2 °C in warming that would have occurred by 2012 if winds hadn't been inordinately strong, the researchers reported online yesterday in Nature Climate
Climate simulations suggest that that upwelling has generally cooled Earth's
climate, stifling about 0.1 °C to 0.2 °C in warming that would have occurred by 2012 if winds hadn't been inordinately strong, the researchers reported online yesterday in Nature Climate
climate, stifling about 0.1 °C to 0.2 °C in
warming that would have occurred by 2012 if winds hadn't been inordinately strong, the researchers reported online yesterday in Nature
Climate Climate Change.
Climate model
simulations show that Pinatubo - like eruptions tend to shorten La Niñas, lengthen El Niños and lead to unusual
warming during neutral periods, the study says.
Model
simulations of 20th century global
warming typically use actual observed amounts of atmospheric carbon dioxide, together with other human (for example chloroflorocarbons or CFCs) and natural (solar brightness variations, volcanic eruptions,...)
climate - forcing factors.
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.
«Despite being very
warm, 2014 still leaves the observed
warming in the lower part of the range of
climate model
simulations.»
Studies such as Otto et al. (2012) display how the numerical scale of the
simulation numbers allows for clear separation between a
climate with lower level of heat - trapping gases (1960s) and the recent period (2000s), such that the 2010 heat wave in western Russia was more likely to occur with the additional
warming due to
climate change (Figure 3).
To investigate cloud —
climate feedbacks in iRAM, the authors ran several global
warming scenarios with boundary conditions appropriate for late twenty - first - century conditions (specifically,
warming signals based on IPCC AR4 SRES A1B
simulations).
Using thus 10 different
climate models and over 10,000
simulations for the weather@home experiments alone, they find that breaking the previous record for maximum mean October temperatures in Australia is at least six times more likely due to global
warming.
«One demanding test of the validity of the computer
simulations of the
climate of the earth is based on temperature records from the Arctic... When tested against the Arctic temperature record, therefore, the computer forecasts are seen to exaggerate the projected
warming by a large amount.»
Many
climate model
simulations focus on the amount of
warming caused by emissions sustained over decades or centuries, but the timing of temperature increases caused by particular emission has been largely overlooked.
Large
warm bias can hinder models» fidelity of
climate simulations and their future projections.
Scientists at Lawrence Livermore National Laboratory within the Atmospheric, Earth, and Energy Division, along with collaborators from the U.K. Met Office and other modeling centers around the world, organized an international multi-model intercomparison project, name CAUSES (Clouds Above the United States and Errors at the Surface), to identify possible causes for the large
warm surface air temperature bias seen in many weather forecast and
climate model
simulations.
Using Mg / Ca paleothermometry from the planktonic foraminifera Globigerinoides ruber from the past 500 k.y. at Ocean Drilling Program (ODP) Site 871 in the western Pacific
warm pool, we estimate the tropical Pacific
climate sensitivity parameter (λ) to be 0.94 — 1.06 °C (W m − 2) − 1, higher than that predicted by model
simulations of the Last Glacial Maximum or by models of doubled greenhouse gas concentration forcing.
A large ensemble of Earth system model
simulations, constrained by geological and historical observations of past
climate change, demonstrates our self ‐ adjusting mitigation approach for a range of
climate stabilization targets ranging from 1.5 to 4.5 °C, and generates AMP scenarios up to year 2300 for surface
warming, carbon emissions, atmospheric CO2, global mean sea level, and surface ocean acidification.
Simulations including an increased solar activity over the last century give a CO2 initiated
warming of 0.2 ˚C and a solar influence of 0.54 ˚C over this period, corresponding to a CO2
climate sensitivity of 0.6 ˚C (doubling of CO2) and a solar sensitivity of 0.5 ˚C (0.1 % increase of the solar constant).
However, satellite observations are notably cooler in the lower troposphere than predicted by
climate models, and the research team in their paper acknowledge this, remarking: «One area of concern is that on average...
simulations underestimate the observed lower stratospheric cooling and overestimate tropospheric
warming... These differences must be due to some combination of errors in model forcings, model response errors, residual observational inhomogeneities, and an unusual manifestation of natural internal variability in the observations.»
First, most
climate simulations, including ours above and those of IPCC [1], do not include slow feedbacks such as reduction of ice sheet size with global
warming or release of greenhouse gases from thawing tundra.
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.
Because this issue continues to affect all coupled ocean - atmosphere models (e.g., 22 — 24), the
warming (Fig. 3) represents the expression of positive biotic feedback mechanisms missing from earlier
simulations of these
climates obtained with prescribed PI concentrations of trace GHGs.
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.
In most future global
warming simulations with
climate models no meltwater from Greenland is included so far.
Simulations including an increased solar activity over the last century give a CO2 initiated
warming of 0.2 ˚C and a solar influence of 0.54 ˚C over this period, corresponding to a CO2
climate sensitivity of 0.6 ˚C (doubling of CO2) and a solar sensitivity of 0.5 ˚C (0.1 % increase of the solar constant).
Polar amplification of
warming arises because the initial baseline
simulations underrepresent the warmth of ancient greenhouse
climates.
Using Mg / Ca paleothermometry from the planktonic foraminifera Globigerinoides ruber from the past 500 k.y. at Ocean Drilling Program (ODP) Site 871 in the western Pacific
warm pool, we estimate the tropical Pacific
climate sensitivity parameter (λ) to be 0.94 — 1.06 °C (W m − 2) − 1, higher than that predicted by model
simulations of the Last Glacial Maximum or by models of doubled greenhouse gas concentration forcing.
Simulations conducted in advance of the 2013 — 14 assessment from the Intergovernmental Panel on
Climate Change (IPCC) suggest that the
warming should have continued at an average rate of 0.21 °C per decade from 1998 to 2012.
Gerald A. Meehl, Haiyan Teng & Julie M. Arblaster, National Center for Atmospheric Research, Boulder, Colorado 80307, USA (http://www.nature.com/nclimate/journal/v4/n10/full/nclimate2357.html): «The slowdown in the rate of global
warming in the early 2000's is not evident in the multi-modal ensemble average of traditional
climate change projection
simulations.»
The total
warming from methane, nitrous oxide and aerosol emissions were each estimated from
climate model
simulations driven by historical forcing pathways for each gas, and were allocated to individual countries as described in section 2.
In the GISS «committed
climate change»
simulations, most of the additional
warming has occured by 2050, but there remains a slow increase for decades afterwards.
Meanwhile, modeling results in this area don't lead to definitive conclusions; as the recent WMO statement puts it, «Although recent
climate model
simulations project a decrease or no change in global tropical cyclone numbers in a
warmer climate there is low confidence in this projection.
I followed up by asking whether broad powerful fronts like those seen in the video emerge in
climate simulations used to assess the impacts of greenhouse
warming.
Kosaka and Xie made global
climate simulations in which they inserted specified observed Pacific Ocean temperatures; they found that the model simulated well the observed global
warming slowdown or «hiatus,» although this experiment does not identify the cause of Pacific Ocean temperature trends.
It is not that the polar regions are amplifying the
warming «going on» at lower latitudes, it is that any
warming going on AT THE POLES is amplified through inherent positive feedback processes AT THE POLES, and specifically this is primarily the ice - albedo positive feedback process whereby more open water leads to more
warming leads to more open water, etc. *** «
Climate model simulations have shown that ice albedo feedbacks associated with variations in snow and sea - ice coverage are a key factor in positive feedback mechanisms which amplify climate change at high northern latitudes...
Climate model
simulations have shown that ice albedo feedbacks associated with variations in snow and sea - ice coverage are a key factor in positive feedback mechanisms which amplify
climate change at high northern latitudes...
climate change at high northern latitudes...»
The same
simulations found that — were the world to achieve the 1.5 °C global
warming limit which 195 nations agreed upon at the Paris
climate summit in 2015 — then the Mediterranean region would experience only 3.2 months of drought.
Using the business - as - usual scenario for GHG radiative forcing (RCP8.5) and their novel estimate of Earth's
warm - phase
climate sensitivity the authors find that the resulting
warming during the 21st century overlaps with the upper range of the Coupled Model Intercomparison Project Phase 5 (CMIP5)
climate simulations.
Most
climate model
simulations show a larger
warming in the tropical troposphere than is found in observational data sets (e.g., McKitrick et al., 2010; Santer et al., 2013).
Dr. Judith Curry notes «The most recent
climate model
simulations used in the AR5 indicate that the
warming stagnation since 1998 is no longer consistent with model projections even at the 2 % confidence level» This means the hypothesis upon which these models have been built is wrong and should be abandoned.
For instance, perfect initialization of the state of the Atlantic ocean, a correct
simulation of the next 10 years of the solar cycle, a proper inclusion of stratospheric water vapor, etc may be important for whether the next 5 years are
warmer than the previous 5, but it has nothing to do with
climate sensitivity, water vapor feedback, or other issues.
http://typhoon.atmos.colostate.edu/Includes/Documents/Publications/gray2012.pdf The Physical Flaws of the Global
Warming Theory and Deep Ocean Circulation Changes as the Primary
Climate Driver The water vapor, cloud, and condensation - evaporation assumptions within the conventional AGW theory and the (GCM)
simulations are incorrectly designed to block too much infrared (IR) radiation to space.
Fyfe and colleagues (2013) find that the observed
warming over the periods 1993 - 2012 and 1998 - 2012 is significantly less than the
warming in
climate model
simulations, but that the same models successfully simulate the rate of
warming over the 1900 - 2012 period.
A realistic treatment of the hydrologic cycle would show that the influence of a doubling of CO2 should lead to a global surface
warming of only about 0.3 °C — not the 3 °C
warming as indicated by the
climate simulations....
There is a couple tenths of a W / m2 of long - term solar forcing (
warming) that is inferred the observed changes in the sunspot cycle (which we include in our
climate simulations, including the UV variations).
Large - eddy
simulation (LES) of clouds can help resolve one of the most important and challenging question in
climate dynamics, namely, how subtropical low clouds respond to global
warming.
Interestingly, though
climate models have differing values for u, it remains almost time - invariant for a wide range of twenty - first century
climate transient
warming scenarios, while varying in
simulations of the twentieth century.