Sentences with phrase «volcanic forcing etc.»

Since the data show southern Greenland temperatures over the last 150 years, it would be most useful to look at model simulations for exactly that period, run with the best guesses for CO2, solar and volcanic forcing etc..

Not exact matches

The response of that model to volcanic forcings, the last ice age, changes in orbital parameters etc. are all «out - of - sample» tests that are not fixed by adjusting parameters.

The interest in these records is for what they can tell us about natural variability, spatial patterns of change, responses to solar or volcanic forcing, teleconnections etc. — it's all interesting and useful, but it is nothing like as important as the outside interest shown in these studies might suggest.

Also, due to the multiplicity of anthropogenic and natural effects on the climate over this time (i.e. aerosols, land - use change, greenhouse gases, ozone changes, solar, volcanic etc.) it is difficult to accurately define the forcings.

And yes, there is such evidence — in the predicted response to volcanic forcing, the ozone hole, orbital variations, the sun, paleo - lake outbursts, the response to ENSO etc. that all show models matching the observations skillfully (which is not to say they match perfectly).

You need information about the degree of intrinsic variability, estimates of the natural forcings (principally solar and volcanic), and estimates of the human related forcings (GHGs, land use change, aerosols etc.).

First, for changing just CO2 forcing (or CH4, etc, or for a non-GHE forcing, such as a change in incident solar radiation, volcanic aerosols, etc.), there will be other GHE radiative «forcings» (feedbacks, though in the context of measuring their radiative effect, they can be described as having radiative forcings of x W / m2 per change in surface T), such as water vapor feedback, LW cloud feedback, and also, because GHE depends on the vertical temperature distribution, the lapse rate feedback (this generally refers to the tropospheric lapse rate, though changes in the position of the tropopause and changes in the stratospheric temperature could also be considered lapse - rate feedbacks for forcing at TOA; forcing at the tropopause with stratospheric adjustment takes some of that into account; sensitivity to forcing at the tropopause with stratospheric adjustment will generally be different from sensitivity to forcing without stratospheric adjustment and both will generally be different from forcing at TOA before stratospheric adjustment; forcing at TOA after stratospehric adjustment is identical to forcing at the tropopause after stratospheric adjustment).

Some of these forcings are well known and understood (such as the well - mixed greenhouse gases, or recent volcanic effects), while others have an uncertain magnitude (solar), and / or uncertain distributions in space and time (aerosols, tropospheric ozone etc.), or uncertain physics (land use change, aerosol indirect effects etc.).

They maintain that the actual forcings (which includes things other than just CO2) are closest to Hansen's scenario B. Remember this wasn't an exercise in predicting future CO2, methane, solar, volcanic, etc. forcings, but a prediction of what could happen under some hypothetical «high», «medium» and «low» forcing scenarios.

The two candidates (apart from volcanic forcing) are solar variability and the natural internal variability of the coupled ocean atmosphere system, e.g. the multi-decadal and longer oscillations such as the NAO, PDO, etc..

Regarding your statement, «Perhaps it is known that the natural variations in surface temperature are all due to unforced mechanisms, otherwise it is simply an assertion», I assume by «natural variations» you mean ENSO, PDO, AMO, etc., because obviously natural changes in solar irradiance or volcanic aerosols are recognized as forcing mechanisms.

I am surprised when you say that volcanic forcing dominates the models - this seems at odds to papers by Lean and Rind etc..»

In the climate case, we need to know how well we estimated forcings (greenhouse gases, volcanic effects, aerosols, solar etc.) in the projections.

At first sight this statement seems valid, however the variability in global T is not only determined by anthropogenic forcings but is also determined by natural variability like ENSO, Volcanic eruptions, solar variation etc..