Sentences with phrase «natural radiative forcings»

This «hiatus» is probably due to the cooling influences from natural radiative forcings (more volcanic eruptions and reducing output from the sun as part of the natural 11 - year solar cycle) and internal variability (fluctuations within the oceans unrelated to forcings).

In order to be thorough, we can also include the natural radiative forcings.

When these same models are forced with only natural radiative forcing during the 20th century [see e.g. Crowley (2000)-RSB- they actually exhibit a modest cooling trend.

Gregory et al. (2002) used observed interior - ocean temperature changes, surface temperature changes measured since 1860, and estimates of anthropogenic and natural radiative forcing of the climate system to estimate its climate sensitivity.

In other words, the same natural forcings that appear responsible for the modest large - scale cooling of the LIA should have lead to a cooling trend during the 20th century (some warming during the early 20th century arises from a modest apparent increase in solar irradiance at that time, but the increase in explosive volcanism during the late 20th century leads to a net negative 20th century trend in natural radiative forcing).

Summary for Policymakers Chapter 1: Introduction Chapter 2: Observations: Atmosphere and Surface Chapter 3: Observations: Ocean Chapter 4: Observations: Cryosphere Chapter 5: Information from Paleoclimate Archives Chapter 6: Carbon and Other Biogeochemical Cycles Chapter 7: Clouds and Aerosols Chapter 8: Anthropogenic and Natural Radiative Forcing Chapter 8 Supplement Chapter 9: Evaluation of Climate Models Chapter 10: Detection and Attribution of Climate Change: from Global to Regional Chapter 11: Near - term Climate Change: Projections and Predictability Chapter 12: Long - term Climate Change: Projections, Commitments and Irreversibility Chapter 13: Sea Level Change Chapter 14: Climate Phenomena and their Relevance for Future Regional Climate Change Chapter 14 Supplement Technical Summary

It presents a significant reinterpretation of the region's recent climate change origins, showing that atmospheric conditions have changed substantially over the last century, that these changes are not likely related to historical anthropogenic and natural radiative forcing, and that dynamical mechanisms of interannual and multidecadal temperature variability can also apply to observed century - long trends.

However, IPCC also concedes that its «level of scientific understanding» of «natural radiative forcing components» (including «solar») is «low».

Natural radiative forcing (solar + volcanic) actually leads to a net cooling over the 20th century, and the remaining (internal) natural variability could not possibly account for the late 20th century warming.

«these changes are not likely related to historical anthropogenic and natural radiative forcing»

Methane [vs.] carbon dioxide: Myhre, Gunnar, Drew Shindell, François - Marie Bréon, William Collins, Jan Fuglestvedt, Jianping Huang, Dorothy Koch et al. «Anthropogenic and natural radiative forcing.»

«70 % of U.S. television news segments have provided «balanced» coverage regarding anthropogenic contributions to climate change vis - à - vis natural radiative forcing, and there has been a significant difference between this television coverage and scientific consensus regarding anthropogenic climate change from 1996 through 2004.»

Through quantitative content analysis, results show that 70 % of U.S. television news segments have provided «balanced» coverage regarding anthropogenic contributions to climate change vis - à - vis natural radiative forcing, and there has been a significant difference between this television coverage and scientific consensus regarding anthropogenic climate change from 1996 through 2004.

Quite clearly the natural radiative forcing does not increase at a constant linear rate from 1850 to 2010, and thus the assumption which is the backbone of the L&S model is faulty.

Lamarque, D. Lee, B. Mendoza, T. Nakajima, A. Robock, G. Stephens, T. Takemura, and H. Zhang, 2013: Anthropogenic and natural radiative forcing.

The patterns of temperature change imply dynamical responses of climate to natural radiative forcing changes involving El Niño and the North Atlantic Oscillation — Arctic Oscillation.»

Figure 1: Anthropogenic plus natural vs. just natural radiative forcing temperature change vs. observed global surface temperature increase (Meehl 2004)

«Working on the IPCC, there was a lot of discussion of climate sensitivity since it's so important for our future,» said Shindell, who was lead author of the IPCC Fifth Assessment Report's chapter on Anthropogenic and Natural Radiative Forcing.

Not exact matches

The new findings of successful multi-year drought / fire predictions are based on a series of computer modeling experiments, using the state - of - the - art earth system model, the most detailed data on current ocean temperature and salinity conditions, and the climate responses to natural and human - linked radiative forcing.

Results from climate models driven by estimated radiative forcings for the 20th century (Chapter 9) suggest that there was little change prior to about 1915, and that a substantial fraction of the early 20th - century change was contributed by naturally occurring influences including solar radiation changes, volcanism and natural variability.

«In today's atmosphere, the radiative forcing from human activities is much more important for current and future climate change than the estimated radiative forcing from changes in natural processes.»

Numerous climate modeling experiments which have included the role of natural (both solar and volcanic) radiative forcing have concluded that natural forcing can not explain 20th century warming.

Despite your insistence otherwise, you evince at best a shallow understanding of basic principles of climate science (hint: while radiative forcing is known to be at least partially controlled by atmospheric CO2, no «natural», i.e. internal source of variability has been demonstrated that could drive a global temperature trend for half a century), as well as an inability to recognize genuine expertise.

One can see a number of basic flaws here; the complete lack of appreciation of the importance of natural variability on short time scales, the common but erroneous belief that any attribution of past climate change to solar or other forcing means that CO2 has no radiative effect, and a hopeless lack of familiarity of the basic science of detection and attribution.

It's painfully easy to paint oneself logically into a corner by arguing that either (i) vigorous natural variability caused 20th century climate change, but the climate is insensitive to radiative forcing by greenhouse gases; or (ii) the climate is very sensitive to greenhouse gases, but we still are able to attribute details of inter-decadal wiggles in the global mean temperature to a specific forcing cause.

As we have discussed several times elsewhere on this site, studies employing model simulations of the past millennium have been extremely successful in reproducing many of the details evident in paleoclimate reconstructions of this interval as a forced response of the climate to natural (primarly volcanic and solar) and in more recent centuries, anthropogenic, radiative changes.

Also your inability to see that natural variability occurs on climate path based on the radiative forcing illustrates your basic misunderstanding of these realities.

The NCAR CSM 1.4 was driven by the radiative forcings (volcanic + solar natural and anthropogenic ghg + aerosol) developed in Ammann et al (2007).

[Response: But the radiative forcing is the natural logarithm of the [CO2] ratio at two time points.

[Dr. Carling has] the complete lack of appreciation of the importance of natural variability on short time scales, the -LSB-...] erroneous belief that any attribution of past climate change to -LSB-...] other [than CO2] forcing means that CO2 has no radiative effect, and a hopeless lack of familiarity of the basic science of detection and attribution.

«The IPCC has failed to convincingly explain the pause in terms of external radiative forcing from greenhouse gases...» — That's because the tropospheric pause has nothing to do with GH gases, which never «pause» in their action, bit rather, the pause has everything to do with natural variability in the rate of energy flow from ocean to atmosphere.

The IPCC has failed to convincingly explain the pause in terms of external radiative forcing from greenhouse gases, aerosols, solar or volcanic forcing; this leaves natural internal variability as the predominant candidate to explain the pause.

All natural variation is now occurring on a different radiative forcing path.

Fortunately, the negative and positive forcings are roughly equal and cancel each other out, and the natural forcings over the past half century have also been approximately zero (Meehl 2004), so the radiative forcing from CO2 alone gives us a good estimate as to how much we expect to see the Earth's surface temperature change.

The higher frequency content in the temperature series by necessary assumption arises from other radiative forcings as well as natural heat flux oscillations.

that's the point, pogac is not just natural variability, sst in the enso regions are affected by radiative forcing too.

In POGA - H, the radiative forcing is identical to HIST, and in the POGA control experiment (POGA - C) it is fixed at the 1990 value [natural internal variability only].

A perturbation of this global radiation balance, be it human - induced or natural, is called radiative forcing.

Scientists keep track of natural forcings, but the observed warming of the planet over the second half of the 20th century can only be explained by adding in anthropogenic radiative forcings, namely increases in greenhouse gases such as carbon dioxide.

BBD, As relieved as we are a devout «believer» such as yourself is finally stumbling towards a grasp of the basic principles of radiative physics etc, you need to now start thinking about joining the adult discussions on vastly less clear problems like the * size * of the AGW effect of AGW compared to natural forces, feedbacks etc..

A linear warming trend plus natural cycles can be mistaken for a step function, but physically the global warming is caused by an external radiative forcing (i.e. human greenhouse gas emissions).

Natural cycles superimposed on a linear warming trend can be mistaken for step changes, but the underlying warming is caused by the external radiative forcing.

Before the industrial period, the natural variations in the total amount of effective solar radiative forcing reinforce the thermal contrasts both between the ocean and continent and between the Northern and Southern Hemispheres resulting in the millennium - scale variation and the quasi-bicentennial oscillation in the GM index.

We know the climate sensitivity to radiative forcing to be about 3 °C per 4 W / m2 of forcing to within something like a 10 % uncertainty, base on current climate modeling and the geological record (see Hansen et al., 2008) for details http://pubs.giss.nasa.gov/abs/ha00410c.html The natural (unforced) variability of the climate system is going to remain highly uncertain for the foreseeable future.

-LSB-...] With the increase in irradiance and a decline in explosive volcanism in the early 20th century, global temperatures might then have returned to an unperturbed level similar to that of the MQP [Medieval Quiet Period], but the rapid rise in anthropogenic greenhouse gases propelled temperatures well beyond that level, as positive anthropogenic radiative forcing overwhelmed natural variability (Myhre et al., 2013).»

In point of fact the radiative forcings from various natural and anthropogenic causes have been quantified.

«Causes of differences in model and satellite tropospheric warming rates» «Comparing tropospheric warming in climate models and satellite data» «Robust comparison of climate models with observations using blended land air and ocean sea surface temperatures» «Coverage bias in the HadCRUT4 temperature series and its impact on recent temperature trends» «Reconciling warming trends» «Natural variability, radiative forcing and climate response in the recent hiatus reconciled» «Reconciling controversies about the «global warming hiatus»»

Irrespective of what one thinks about aerosol forcing, it would be hard to argue that the rate of net forcing increase and / or over-all radiative imbalance has actually dropped markedly in recent years, so any change in net heat uptake can only be reasonably attributed to a bit of natural variability or observational uncertainty.

For «skeptics» to make a convincing argument that humans are not causing global warming, they must both explain where this large greenhouse gas radiative forcing has gone, and find an even larger «natural» radiative forcing which nobody has yet identified.

Rud M Huber and Reto Knuttti just published a Nature Geosciences paper 17 Aug «Natural variability, radiative forcing and climate response in the recent hiatus reconciled» vol 7 Sep 2014 that purports to analyze the hiatus vs CMIP5 models and finds the pause consistent with a reduced complexity model and mean of models.