Sentences with phrase «observed global»

Figure 1: Percent contributions of greenhouse gases (GHGs), sulfur dioxide (SO2), the sun, volcanoes, and El Niño Southern Oscillation (ENSO) to the observed global surface warming over the past 50 - 65 years according to Tett et al. 2000 (T00, dark blue), Meehl et al. 2004 (M04, red), Stone et al. 2007 (S07, green), Lean and Rind 2008 (LR08, purple), Huber and Knutti 2011 (HK11, light blue), Gillett et al. 2012 (G12, orange), and Wigley and Santer 2012 (WS12, dark green).
Using Google to find citing papers, I came across a paper that appears to have been written in response, «Why are climate models reproducing the observed global surface warming so well?»
One piece of the puzzle has been provided by a new paper A large discontinuity in the mid-twentieth century in observed global - mean surface temperature (Thompson 2008).
Observed global trends are about 1.6 C / century for the satellite era.
``... observed global warming is now attributed with high confidence to increasing greenhouse gases (IPCC 2007a).»
A number of studies have used a variety of statistical and physical approaches to determine the contribution of greenhouse gases and other effects to the observed global warming.
There is strong circumstantial evidence that this positive forcing is responsible for the observed global warming of about 3/4 °C in the past century.
The study authors compared the simulations that were correctly synchronized with the ocean cycles (blue data in the left frame below) and the most out - of - sync (grey data in the right frame) to the observed global surface temperature changes (red) for each 15 - year period.
Both Lean and Rind and Foster and Rahmstorf found that solar activity has played a very small role in the recent observed global warming.
The data negate increase in CO2 in the atmosphere as a hypothetical cause for the apparently observed global warming.
If we can trust the RF calculation in the absence of effective peer - review — and using the observed global rise in T (criticism of urban heat islands and dodgy grid homogenising algorithms not - withstanding), then 0.7 = X (RF), where the RF for CO2 is.....?
Thus, the observed global mean temperature trend, and the percentile rank of Summit, are likely biased towards lower and higher values, respectively.»
No climate model using natural forcings alone has reproduced the observed global warming trend in the second half of the 20th century.
Theories for the cause of observed global temperature change are thus separated as an independent matter.
The pattern of modeled surface temperature changes induced by solar variability is well correlated with observed global warming over the first half of the 20th century, but not with the more rapid warming seen over the past three decades.
Here, the GHE will, for all intents and purposes, be defined as the set of conditions that are responsible for discrepancy between the observed global mean surface temperature of a planet and that predicted based on the energy flux received from the sun, rather than being restricted to a mere radiative balance.
Equation 1 implies a value of T e = 254 K for the terrestrial emission temperature, whereas the observed global mean surface temperature is T ≈ 288 K.
It will be demonstrated that sustained volcanic outgassing was the primary source of carbon dioxide during OAE 1a and was the ultimate driver of the observed global warming with reconstructed temperatures during OAE 1a being higher than found anywhere during the Cenozoic.
From the IPCC AR4: «The fact that climate models are only able to reproduce observed global mean temperature changes over the 20th century when they include anthropogenic forcings, and that they fail to do so when they exclude anthropogenic forcings, is evidence for the influence of humans on global climate.»
They also ran atmospheric models that used observed global sea surface temperatures, Arctic sea ice conditions and atmospheric carbon dioxide concentrations in 2010 to assess whether such factors might have contributed to the heat wave.
The sun has not changed enough, especially in the last 3 decades, to account for the rapidity and magnitude of the observed global climate change.
pdf cited by Will ««Observed global sea ice area, defined here as a sum of N. Hemisphere and S. Hemisphere sea ice areas, is near or slightly lower than those observed in late 1979.»
Models are able to reproduce many features of the observed global and Northern Hemispher (NH) mean temperature variance on interannual to centennial time scales (high confidence), and most models are now able to reproduce the observed peak in variability associated with the El Niño (2 - to 7 - year period) in the Tropical Pacific.
Modelled versus observed global sea - level rise.
Removing this internal signature from the observed global mean temperature record should clean up the individual and unique realization of nature, isolating the forced climate signal.
DelSole et al. (28) also found 2.5 cycles by extracting the spatial pattern in the Intergovernmental Panel on Climate Change, Fourth Assessment Report (IPCC AR4)(29) model control runs that best characterizes internal variability and by projecting the observed global data onto this pattern.
The whole idea of dealing with global mean temperatures and averaged - out energy budgets is by itself crude, and one commenter at least has noted that when an observed global warming of the order of 1C is small compared to the coarseness and sensitivity of such back of an envelope calculations, we need to look elsewhere to resolve disputes.
Removal of that hidden variability from the actual observed global mean surface temperature record delineates the externally forced climate signal, which is monotonic, accelerating warming during the 20th century.
This procedure is philosophically similar to that used to remove the interannual El Niño signal from observed global mean temperature trends (14), with the caveat that the observed time series are not sufficiently long to statistically identify the signature of inter-decadal internal climate variability on the global mean temperature, necessitating the use of long time - period climate model integrations.
The observed global - warming rate has been nonuniform, and the cause of each episode of slowing in the expected warming rate is the subject of intense debate.
Figure 1: Anthropogenic plus natural vs. just natural radiative forcing temperature change vs. observed global surface temperature increase (Meehl 2004)
They universally find that humans are the dominant cause of the observed global warming over the past 150 years, 100 years, 50 years, 25 years, etc..
«Estimates of the observed global warming for the recent 15 - year period 1998 - 2012 vary between 0.0037 °C / year (NCDC), 0.0041 °C / year (HadCRUT4) and 0.008 °C / year (GISS).
My quote referred to the assertion that there was an increasing discrepancy between observed global temperatures and model simulated global temperature used for the global warming predictions presented in the IPCC report.
Comparison of the observed global - mean temperature record with climate model simulations serves to validate (and better understand) climate model performance and ability to simulate the global - mean temperature component of global climate change in response to radiative forcings.
Human - caused increases in greenhouse gases are responsible for most of the observed global average surface warming of roughly 0.8 °C (1.5 °F) over the past 140 years.
Under the adjustments to the observed global temperature history put together by Cowtan and Way, the models fare a bit better than they do with the unadjusted temperature record.
Specifically, while the trend in observed global temperatures from 1979 - 2012 as calculated by Cowtan and Way is 0.17 °C / decade, it is 0.16 °C / decade in the temperature record compiled by the U.K. Hadley Center (the record that Cowtan and Way adjusted).
The advanced climate model output clearly misses all the big extremes and wide variations of observed global temperatures, including this El Niño's recent incredible burst of warming
And contrary to Curry's second point, the observed global warming has been consistent with the projections of the range of models used in the IPCC report.
Exactly — e.g., I was sure that it was «very likely» that humans were the cause of observed global warming but now that I know humans are not responsible for all of the observed global warming, I am even more confident in my belief that it is «extremely likely» humans are at least responsible for half of it.
96 percent of these said that humans are the primary cause of the observed global warming since 1950.
That is almost twice the observed global rate of 0.5 to 0.7 inches per decade over a similar time period.
First off, about a year after the IPCC released its AR4 report (from which the EPA took its statement), David Thompson and colleagues published a paper in Nature magazine titled «A large discontinuity in the mid-twentieth century in observed global - mean surface temperature.»
At this point, the best available science says that GCRs probably have an impact, but that the impact is insufficient to account for the bulk of the observed global warming over the last 130 years or so.
They do play their role, no doubt about that, but you need aerosols to explain most of the observed global temperature pattern.
So, inputting actual values of the cooling effect (such as the determination by Penner et al.) would make every climate model provide a mismatch of the global warming it hindcasts and the observed global warming for the twentieth century.
However, not all scientists agree that the observed global warming is due to greenhouse gases.
We've seen how close observed global temperatures have come to pre-industrial +1.5 degrees, the important ambition following from the Paris climate summit.
The iconic figure showing agreement between simulated and observed global temperature over the 20th century should not be interpreted itself as the attribution of anthropogenic influence on climate.
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