Sentences with phrase «observed changes in forcing»

The test of the model is whether, given the observed changes in forcing, it produces a skillful prediction using the scenario most closely related to the observations — which is B (once you acknowledge the slight overestimate in the forcings).

Not exact matches

BOX 15, A-15-6; 30219214 / 734997 SAPA Part B - 1st Draft, c. 1972 Using Numbers - Numbers and the Number Line, JRM Observing - Observing the Weather Measuring - Making Comparisions Using a Balance, JE Alternate Auto - Instructional, Measuring 1 - 4 / Measuring Area, Gillis Classifying - Trees in our Environment, JRM, c. 1972 AAAS - Xerox Film Loops Guide, A11 Exercises - Shapes and Symmetry, Hansen, 1972 SAPA Part B - 1st Draft, 1972 Observing - Observing Color and Color Changes in Plants, HM Communicating - Identifying Objects and their Variations, RN Communicating - Different Kinds of Forces, AHL Communicating - Graphs, JRM Classifying - Observing Living and Nonliving Things, Smith Using Space / Time Classifying - Animals in Our Environment: Part B (alternate) Using Space / Time - Shadows, Smtih Alternate (Autoinstructional)- Using Numbers - Numbers and the Number Line Observing - Observing Soils, JRM SAPA Part B 2nd Draft, 1972 Measuring Area 1 - 4, CCP Measuring 1 - 4, Volume of Solids, Alternate 2, CCP Measuring 1 - 4, Volume of Solids, Alternate 1, CCP Measuring Length 4 - 6, Linear Measurement Using Metric Units, CCP Communicating - Intro to Graphing, JRM Communicating - Pushes and Pulls, AHL Communicating - Identifying Objects and Their Variations, RN Classifying - Trees in Our Environment, JRM Classufying - Observing Living and Nonliving Things, Smith Observing - Observing Color and Color Changes in Plants and Observing Changes in Mold Gardens, HGM Observing (alternate)- Observation, Using Several of the Senses, HGM, c. 1972 Using Numbers - Numbers and the Number Line, JRM Measuring - Making Comparisions Using a Balance, JWE Using Space / Time - Shadows, Smith Using Space / Time Relationships - Time Intervals, HGM Observing 10 - Observing the Weather, JWE Observing - Observing Soils Using Several of the Senses, JRM SAPA Part B Tryout Draft, 1972 Communicating - The Same but Different Observing 10 - Observing the Weather Observing 9A - Observing Soils Observing (alternate)- Using Several of the Senses Observing - Observing Change Classifying - Trees in Our Environment Classifying - Observing Living and Nonliving Things SAPA Part B, Observing - Changes in Molds and Other Plants, c. 1972 SAPA Part B Tryout Draft, 1972 Observing - Observing Changes in Plants Observing - Changes in Mold and Green Plants Measuring - Making Comparisions Using a Balance Measuring Length - Linear Measurement Using Metric Units Measuring Volumes of Solids, 1 - 4 Communicating - Pushes and Pulls Comparing Area, c. 1972 Using Space / Time Relationships - Shadows, 1972 Addition of Postive Numbers, Sums 1 - 99 (not being tried) SAPA Part B 3rd Draft (alternate), Using Numbers - Numbers and the Number Line, 1972 SAPA Part C 1st Draft, 1972 Classifying - Classifying Components of Mixtures, Livermore Inferring 2 - How Certain Can You Be?

Taking factors such as sea surface temperature, greenhouse gases and natural aerosol particles into consideration, the researchers determined that changes in the concentration of black carbon could be the primary driving force behind the observed alterations to the hydrological cycle in the region.

g (acceleration due to gravity) G (gravitational constant) G star G1.9 +0.3 gabbro Gabor, Dennis (1900 — 1979) Gabriel's Horn Gacrux (Gamma Crucis) gadolinium Gagarin, Yuri Alexeyevich (1934 — 1968) Gagarin Cosmonaut Training Center GAIA Gaia Hypothesis galactic anticenter galactic bulge galactic center Galactic Club galactic coordinates galactic disk galactic empire galactic equator galactic habitable zone galactic halo galactic magnetic field galactic noise galactic plane galactic rotation galactose Galatea GALAXIES galaxy galaxy cannibalism galaxy classification galaxy formation galaxy interaction galaxy merger Galaxy, The Galaxy satellite series Gale Crater Galen (c. AD 129 — c. 216) galena GALEX (Galaxy Evolution Explorer) Galilean satellites Galilean telescope Galileo (Galilei, Galileo)(1564 — 1642) Galileo (spacecraft) Galileo Europa Mission (GEM) Galileo satellite navigation system gall gall bladder Galle, Johann Gottfried (1812 — 1910) gallic acid gallium gallon gallstone Galois, Évariste (1811 — 1832) Galois theory Galton, Francis (1822 — 1911) Galvani, Luigi (1737 — 1798) galvanizing galvanometer game game theory GAMES AND PUZZLES gamete gametophyte Gamma (Soviet orbiting telescope) Gamma Cassiopeiae Gamma Cassiopeiae star gamma function gamma globulin gamma rays Gamma Velorum gamma - ray burst gamma - ray satellites Gamow, George (1904 — 1968) ganglion gangrene Ganswindt, Hermann (1856 — 1934) Ganymede «garbage theory», of the origin of life Gardner, Martin (1914 — 2010) Garneau, Marc (1949 ---RRB- garnet Garnet Star (Mu Cephei) Garnet Star Nebula (IC 1396) garnierite Garriott, Owen K. (1930 ---RRB- Garuda gas gas chromatography gas constant gas giant gas laws gas - bounded nebula gaseous nebula gaseous propellant gaseous - propellant rocket engine gasoline Gaspra (minor planet 951) Gassendi, Pierre (1592 — 1655) gastric juice gastrin gastrocnemius gastroenteritis gastrointestinal tract gastropod gastrulation Gatewood, George D. (1940 ---RRB- Gauer - Henry reflex gauge boson gauge theory gauss (unit) Gauss, Carl Friedrich (1777 — 1855) Gaussian distribution Gay - Lussac, Joseph Louis (1778 — 1850) GCOM (Global Change Observing Mission) Geber (c. 720 — 815) gegenschein Geiger, Hans Wilhelm (1882 — 1945) Geiger - Müller counter Giessler tube gel gelatin Gelfond's theorem Gell - Mann, Murray (1929 ---RRB- GEM «gemination,» of martian canals Geminga Gemini (constellation) Gemini Observatory Gemini Project Gemini - Titan II gemstone gene gene expression gene mapping gene pool gene therapy gene transfer General Catalogue of Variable Stars (GCVS) general precession general theory of relativity generation ship generator Genesis (inflatable orbiting module) Genesis (sample return probe) genetic code genetic counseling genetic disorder genetic drift genetic engineering genetic marker genetic material genetic pool genetic recombination genetics GENETICS AND HEREDITY Geneva Extrasolar Planet Search Program genome genome, interstellar transmission of genotype gentian violet genus geoboard geode geodesic geodesy geodesy satellites geodetic precession Geographos (minor planet 1620) geography GEOGRAPHY Geo - IK geologic time geology GEOLOGY AND PLANETARY SCIENCE geomagnetic field geomagnetic storm geometric mean geometric sequence geometry GEOMETRY geometry puzzles geophysics GEOS (Geodetic Earth Orbiting Satellite) Geosat geostationary orbit geosynchronous orbit geosynchronous / geostationary transfer orbit (GTO) geosyncline Geotail (satellite) geotropism germ germ cells Germain, Sophie (1776 — 1831) German Rocket Society germanium germination Gesner, Konrad von (1516 — 1565) gestation Get Off the Earth puzzle Gettier problem geyser g - force GFO (Geosat Follow - On) GFZ - 1 (GeoForschungsZentrum) ghost crater Ghost Head Nebula (NGC 2080) ghost image Ghost of Jupiter (NGC 3242) Giacconi, Riccardo (1931 ---RRB- Giacobini - Zinner, Comet (Comet 21P /) Giaever, Ivar (1929 ---RRB- giant branch Giant Magellan Telescope giant molecular cloud giant planet giant star Giant's Causeway Giauque, William Francis (1895 — 1982) gibberellins Gibbs, Josiah Willard (1839 — 1903) Gibbs free energy Gibson, Edward G. (1936 ---RRB- Gilbert, William (1544 — 1603) gilbert (unit) Gilbreath's conjecture gilding gill gill (unit) Gilruth, Robert R. (1913 — 2000) gilsonite gimbal Ginga ginkgo Giotto (ESA Halley probe) GIRD (Gruppa Isutcheniya Reaktivnovo Dvisheniya) girder glacial drift glacial groove glacier gland Glaser, Donald Arthur (1926 — 2013) Glashow, Sheldon (1932 ---RRB- glass GLAST (Gamma - ray Large Area Space Telescope) Glauber, Johann Rudolf (1607 — 1670) glaucoma glauconite Glenn, John Herschel, Jr. (1921 ---RRB- Glenn Research Center Glennan, T (homas) Keith (1905 — 1995) glenoid cavity glia glial cell glider Gliese 229B Gliese 581 Gliese 67 (HD 10307, HIP 7918) Gliese 710 (HD 168442, HIP 89825) Gliese 86 Gliese 876 Gliese Catalogue glioma glissette glitch Global Astrometric Interferometer for Astrophysics (GAIA) Global Oscillation Network Group (GONG) Globalstar globe Globigerina globular cluster globular proteins globule globulin globus pallidus GLOMR (Global Low Orbiting Message Relay) GLONASS (Global Navigation Satellite System) glossopharyngeal nerve Gloster E. 28/39 glottis glow - worm glucagon glucocorticoid glucose glucoside gluon Glushko, Valentin Petrovitch (1908 — 1989) glutamic acid glutamine gluten gluteus maximus glycerol glycine glycogen glycol glycolysis glycoprotein glycosidic bond glycosuria glyoxysome GMS (Geosynchronous Meteorological Satellite) GMT (Greenwich Mean Time) Gnathostomata gneiss Go Go, No - go goblet cell GOCE (Gravity field and steady - state Ocean Circulation Explorer) God Goddard, Robert Hutchings (1882 — 1945) Goddard Institute for Space Studies Goddard Space Flight Center Gödel, Kurt (1906 — 1978) Gödel universe Godwin, Francis (1562 — 1633) GOES (Geostationary Operational Environmental Satellite) goethite goiter gold Gold, Thomas (1920 — 2004) Goldbach conjecture golden ratio (phi) Goldin, Daniel Saul (1940 ---RRB- gold - leaf electroscope Goldstone Tracking Facility Golgi, Camillo (1844 — 1926) Golgi apparatus Golomb, Solomon W. (1932 — 2016) golygon GOMS (Geostationary Operational Meteorological Satellite) gonad gonadotrophin - releasing hormone gonadotrophins Gondwanaland Gonets goniatite goniometer gonorrhea Goodricke, John (1764 — 1786) googol Gordian Knot Gordon, Richard Francis, Jr. (1929 — 2017) Gore, John Ellard (1845 — 1910) gorge gorilla Gorizont Gott loop Goudsmit, Samuel Abraham (1902 — 1978) Gould, Benjamin Apthorp (1824 — 1896) Gould, Stephen Jay (1941 — 2002) Gould Belt gout governor GPS (Global Positioning System) Graaf, Regnier de (1641 — 1673) Graafian follicle GRAB graben GRACE (Gravity Recovery and Climate Experiment) graceful graph gradient Graham, Ronald (1935 ---RRB- Graham, Thomas (1805 — 1869) Graham's law of diffusion Graham's number GRAIL (Gravity Recovery and Interior Laboratory) grain (cereal) grain (unit) gram gram - atom Gramme, Zénobe Théophile (1826 — 1901) gramophone Gram's stain Gran Telescopio Canarias (GTC) Granat Grand Tour grand unified theory (GUT) Grandfather Paradox Granit, Ragnar Arthur (1900 — 1991) granite granulation granule granulocyte graph graph theory graphene graphite GRAPHS AND GRAPH THEORY graptolite grass grassland gravel graveyard orbit gravimeter gravimetric analysis Gravitational Biology Facility gravitational collapse gravitational constant (G) gravitational instability gravitational lens gravitational life gravitational lock gravitational microlensing GRAVITATIONAL PHYSICS gravitational slingshot effect gravitational waves graviton gravity gravity gradient gravity gradient stabilization Gravity Probe A Gravity Probe B gravity - assist gray (Gy) gray goo gray matter grazing - incidence telescope Great Annihilator Great Attractor great circle Great Comets Great Hercules Cluster (M13, NGC 6205) Great Monad Great Observatories Great Red Spot Great Rift (in Milky Way) Great Rift Valley Great Square of Pegasus Great Wall greater omentum greatest elongation Green, George (1793 — 1841) Green, Nathaniel E. Green, Thomas Hill (1836 — 1882) green algae Green Bank Green Bank conference (1961) Green Bank Telescope green flash greenhouse effect greenhouse gases Green's theorem Greg, Percy (1836 — 1889) Gregorian calendar Grelling's paradox Griffith, George (1857 — 1906) Griffith Observatory Grignard, François Auguste Victor (1871 — 1935) Grignard reagent grike Grimaldi, Francesco Maria (1618 — 1663) Grissom, Virgil (1926 — 1967) grit gritstone Groom Lake Groombridge 34 Groombridge Catalogue gross ground, electrical ground state ground - track group group theory GROUPS AND GROUP THEORY growing season growth growth hormone growth hormone - releasing hormone growth plate Grudge, Project Gruithuisen, Franz von Paula (1774 — 1852) Grus (constellation) Grus Quartet (NGC 7552, NGC 7582, NGC 7590, and NGC 7599) GSLV (Geosynchronous Satellite Launch Vehicle) g - suit G - type asteroid Guericke, Otto von (1602 — 1686) guanine Guiana Space Centre guidance, inertial Guide Star Catalog (GSC) guided missile guided missiles, postwar development Guillaume, Charles Édouard (1861 — 1938) Gulf Stream (ocean current) Gulfstream (jet plane) Gullstrand, Allvar (1862 — 1930) gum Gum Nebula gun metal gunpowder Gurwin Gusev Crater gut Gutenberg, Johann (c. 1400 — 1468) Guy, Richard Kenneth (1916 ---RRB- guyot Guzman Prize gymnosperm gynecology gynoecium gypsum gyrocompass gyrofrequency gyropilot gyroscope gyrostabilizer Gyulbudagian's Nebula (HH215)

The CTD sections show that the deeper layers are also warmer and slightly saltier and the observed sea level can be explained by steric expansion over the upper 2000 m. ENSO variability impacts on the northern part of the section, and a simple Sverdrup transport model shows how large - scale changes in the wind forcing, related to the Southern Annular Mode, may contribute to the deeper warming to the south.

Investigating the cause of 20th Century warming is properly done in detection and attribution studies, which analyze the various forcings (e.g., solar variations, greenhouse gases or volcanic activity) and the observed time and space patterns of climate change in detail.

Thus, we conclude that 20th - century land - use changes contributed more to forcing observed regional climate change during the summer in the central United States than increasing GHG emissions.

A: Climate changes observed over recent decades are inconsistent with trends caused by natural forces but are totally consistent with the increase in human - induced heat - trapping gases.

While Milankovitch forcing predicts that cyclic changes in the Earth's orbital parameters can be expressed in the glaciation record, additional explanations are necessary to explain which cycles are observed to be most important in the timing of glacial — interglacial periods.

Wigley et al. (1997) pointed out that uncertainties in forcing and response made it impossible to use observed global temperature changes to constrain ECS more tightly than the range explored by climate models at the time (1.5 °C to 4.5 °C), and particularly the upper end of the range, a conclusion confirmed by subsequent studies.

Test of transfer (long - term): Gonzalo - Skok et al. (2016) observed a tendency for force vector specificity to influence changes in COD ability, when comparing squats with a volume - matched range of similar multi-directional exercises, including both horizontal and lateral movements.

For example, in school science classes, students are manipulating variables such as forces, angles, distances and time and observing the effects of these changes in virtual environments that are sometimes difficult or impossible to create in normal classrooms.

Neither mid-corner bumps nor last - minute changes in throttle application upset the Camaro, while wide, grippy summer tires on 20 - inch wheels let you build heroic g - forces (which you can observe using the real - time digital gauge in the instrument cluster).

Investigating the cause of 20th Century warming is properly done in detection and attribution studies, which analyze the various forcings (e.g., solar variations, greenhouse gases or volcanic activity) and the observed time and space patterns of climate change in detail.

In a series of papers, we've shown that the warmer temperatures observed over the WAIS are the result of those same atmospheric circulation changes, which are not related to the SAM, but rather to the remote forcing from changes in the tropical Pacific: changes in the character of ENSO (Steig et al., 2012; Ding et al., 2011; 2012In a series of papers, we've shown that the warmer temperatures observed over the WAIS are the result of those same atmospheric circulation changes, which are not related to the SAM, but rather to the remote forcing from changes in the tropical Pacific: changes in the character of ENSO (Steig et al., 2012; Ding et al., 2011; 2012in the tropical Pacific: changes in the character of ENSO (Steig et al., 2012; Ding et al., 2011; 2012in the character of ENSO (Steig et al., 2012; Ding et al., 2011; 2012).

The assessment based on these results typically takes into account the number of studies, the extent to which there is consensus among studies on the significance of detection results, the extent to which there is consensus on the consistency between the observed change and the change expected from forcing, the degree of consistency with other types of evidence, the extent to which known uncertainties are accounted for in and between studies, and whether there might be other physically plausible explanations for the given climate change.

The important point here is that a small external forcing (orbital for ice - ages, or GHG plus aerosols & land use changes in the modern context) can be strongly amplified by the positive feedback mechanism (the strongest and quickest is atmospheric water vapor - a strong GHG, and has already been observed to increase.

The significant difference between the observed decrease of the CO2 sink estimated by the inversion (0.03 PgC / y per decade) and the expected increase due solely to rising atmospheric CO2 -LRB--0.05 PgC / y per decade) indicates that there has been a relative weakening of the Southern Ocean CO2 sink (0.08 PgC / y per decade) due to changes in other atmospheric forcing (winds, surface air temperature, and water fluxes).

[Response: I looked into what you could change in the model that would have done better (there is no such thing as a RIGHT / WRONG distinction — only gradations of skill), and I estimated that a model with a sensitivity of ~ 3 deg C / 2xCO2 give the observed forcings would have had higher skill.

Investigating the cause of 20th Century warming is done in so - called detection and attribution studies, which analyze the various forcings (e.g., solar variations, greenhouse gases or volcanic activity) and the observed time and space patterns of climate change in detail.

For a start, based on what we know about the forcings and the observed evolution of global mean temperature, why would one expect climate change to be a linear warming since 1880 in Moscow?

The basic issue is that nudging surface temperatures in the North Atlantic closer to observed data would probably nudge the Atlantic overturning circulation in the wrong direction since changing the temperature without changing the salinity will give the opposite buoyancy forcing to what would be needed.

``... it is now very likely that anthropogenic forcing has contributed to the observed changes in the frequency and intensity of daily temperature extremes on the global scale since the mid-20th century.

Multi-signal detection and attribution analyses, which quantify the contributions of different natural and anthropogenic forcings to observed changes, show that greenhouse gas forcing alone during the past half century would likely have resulted in greater than the observed warming if there had not been an offsetting cooling effect from aerosol and other forcings.

While this does not invalidate the aerosol indirect effect at all, it underlines the limitations in using satellite observed changes in droplet size to compute the aerosol indirect forcing.

Here we would like to try to distinguish between warming in the nocturnal boundary layer due to a redistribution of heat and warming due to the accumulation of heat... It is likely that the observed warming in minimum temperature, whether caused by additional greenhouse forcing or land use changes or other land surface dynamics, is reflecting a redistribution of heat by turbulence - not an accumulation of heat.

When the IPCC claimed that the GCM models (with GHG forcing included) could replicate the observed changes in global average temperatures do you know if they were referring to a truly global measurement or were they just using the US temp record?

However, this method assumes that the observed change in temperature since pre-industrial times is primarily a response to anthropogenic forcings, that all the other anthropogenic forcings are well quantified, and that the climate sensitivity parameter (Section 6.1) predicted by the GCM is correct (Rodhe et al., 2000).

In 2013, the Intergovernmental Panel on Climate Change Fifth Assessment Report stated a clear expert consensus that: «It is extremely likely [defined as 95 - 100 % certainty] that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic [human - caused] increase in greenhouse gas concentrations and other anthropogenic forcings together.&raquIn 2013, the Intergovernmental Panel on Climate Change Fifth Assessment Report stated a clear expert consensus that: «It is extremely likely [defined as 95 - 100 % certainty] that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic [human - caused] increase in greenhouse gas concentrations and other anthropogenic forcings together.&raquin global average surface temperature from 1951 to 2010 was caused by the anthropogenic [human - caused] increase in greenhouse gas concentrations and other anthropogenic forcings together.&raquin greenhouse gas concentrations and other anthropogenic forcings together.»

Attribution analyses normally directly account for errors in the magnitude of the model's pattern of response to different forcings by the inclusion of factors that scale the model responses up or down to best match observed climate changes.

Close agreement of observed temperature change with simulations for the most realistic climate forcing (scenario B) is accidental, given the large unforced variability in both model and real world.

Detection and attribution of observed changes and responses in systems to anthropogenic forcing is usually a two - stage process (IPCC, 2003).

They are used to investigate the processes responsible for maintaining the general circulation and its natural and forced variability (Chapter 8), to assess the role of various forcing factors in observed climate change (Chapter 9) and to provide projections of the response of the system to scenarios of future external forcing (Chapter 10).

By comparing modelled and observed changes in such indices, which include the global mean surface temperature, the land - ocean temperature contrast, the temperature contrast between the NH and SH, the mean magnitude of the annual cycle in temperature over land and the mean meridional temperature gradient in the NH mid-latitudes, Braganza et al. (2004) estimate that anthropogenic forcing accounts for almost all of the warming observed between 1946 and 1995 whereas warming between 1896 and 1945 is explained by a combination of anthropogenic and natural forcing and internal variability.

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).

Human - induced forcing exhibited a slow rise during the early part of the last century but then accelerated after 1960.2 Thus, these graphs highlight observed changes in climate during the period of rapid increase in human - caused forcing and also reveal how well climate models simulate these observed changes.

The summer - winter changes in insolation are much larger than those due to human - induced greenhouse gas changes; the seasonal change is mainly in the visible part of the electromagnetic spectrum while the greenhouse gas forcing is in the infrared; the greenhouse gas influence is global while the seasonal changes are opposite in the two hemispheres; and we have a much longer history of observing the seasonal changes, so a more or less correct prediction can be made empirically, without any physical understanding.

``... snow pack has decreased and been observed to melt earlier in the calendar year... the observed changes in the hydrological components... can be explained well by anthropogenic forcing (green house gases and aerosols) alone.»

Here we show that accounting for recent cooling in the eastern equatorial Pacific reconciles climate simulations and observations.We present a novel method of uncovering mechanisms for global temperature change by prescribing, in addition to radiative forcing, the observed history of sea surface temperature over the central to eastern tropical Pacific in a climate model.

Because if the climate system were dominated by negative feedbacks, then it would be insensitive and incapable of responding as observed to what all agree were modest changes in forcing.

Spectral radiance emitted to space consistent with Tyndall gas concentrations (confirms ability to calculate radiative forcing); magnitude of Tyndall gas radiative forcing larger than that of all other known forcing agents; observed temperature changes similar in magnitude to those estimated from forcings (confirms ballpark estimates of climate sensitivity); observed pattern of temperature changes match Tyndall gas pattern better than that of all other known forcing agents.

Examination of simulations with and without anthropogenic forcings provides evidence that the observed changes are more likely to be anthropogenic than nature in origin.

Small changes in forcings would not be capable of driving the observed variability during the first half of the C20th.

Nonetheless in 2011, Nature published another article by Camille Parmesan who urged we end the climate debate, «By over-emphasizing the need for rigorous assessment of the specific role of greenhouse - gas forcing in driving observed biological changes, the IPCC effectively yields to the contrarians» inexhaustible demands for more «proof», rather than advancing the most pressing and practical scientific questions.»

But there is no study so far that has compared the observed widening to GCM simulations of twentieth - century climate integrated with historical changes in forcings.

With a dominant internal component having the structure of the observed warming, and with radiative restoring strong enough to keep the forced component small, how can one keep the very strong radiative restoring from producing heat loss from the oceans totally inconsistent with any measures of changes in oceanic heat content?

Observed changes in short term precipitation intensity from previous research and the anticipated changes in flood frequency and magnitude expected due to enhanced greenhouse forcing are not generally evident at this time over large portions of the United States for several different measures of flood flows.

If that were the case in the real climate system, then estimates of ECS from observed changes in GMST and total forcing during the historical period would underestimate true ECS, which relates to pure CO2 forcing.

The fact that the models can be made to simulate unforced climate behavior is of course only a first step in enabling them to simulate forced climate change, but because it involves validation against observed data, it is informative at least in terms of the unforced phenomena in showing that the models have probably estimated the real world phenomena with reasonable accuracy.

As John discussed in his post, there are some issues with this hypothesis (i.e. we know observed forcings like solar irradiance and aerosols can explain most past short - term temperature changes without requiring major contributions from these «climate shifts»).