Sentences with phrase «aerosol change as»

The low estimates of climate sensitivity by Chylek and Lohmann (2008) and Schmittner et al. (2011), ~ 2 °C for doubled CO2, are due in part to their inclusion of natural aerosol change as a climate forcing rather than as a fast feedback (as well as the small LGM - Holocene temperature change employed by Schmittner et al., 2011).»

«This sensitivity is higher than estimated by Schmittner et al., partly because they included natural aerosol changes as a forcing.»

Not exact matches

Combined with a decrease in atmospheric water vapor and a weaker sun due to the most recent solar cycle, the aerosol finding may explain why climate change has not been accelerating as fast as it did in the 1990s.

One aerosol, black carbon, is of increasing concern for Arctic nations worried about the pace of climate change in the far north, which is warming twice as fast as the global average.

Climate change is likely to influence rainfall patterns in the Sierra Nevada as well as the amount of dust that makes its way into the atmosphere, so the hope is that a better understanding of how aerosols affect precipitation will help water managers in the future.

Geoengineering — the intentional manipulation of the climate to counter the effect of global warming by injecting aerosols artificially into the atmosphere — has been mooted as a potential way to deal with climate change.

Black carbon aerosols — particles of carbon that rise into the atmosphere when biomass, agricultural waste, and fossil fuels are burned in an incomplete way — are important for understanding climate change, as they absorb sunlight, leading to higher atmospheric temperatures, and can also coat Arctic snow with a darker layer, reducing its reflectivity and leading to increased melting.

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.

The computer model determines how the average surface temperature responds to changing natural factors, such as volcanoes and the sun, and human factors — greenhouse gases, aerosol pollutants, and so on.

The theory of dangerous climate change is based not just on carbon dioxide warming but on positive and negative feedback effects from water vapor and phenomena such as clouds and airborne aerosols from coal burning.

They also found that streams of electrons and protons known as the solar wind, affecting Earth's global electric field, lead to changes in aerosol formation, which ultimately impact rainfall.

Non-polar glacial ice holds a wealth of information about past changes in climate, the environment and especially atmospheric composition, such as variations in temperature, atmospheric concentrations of greenhouse gases and emissions of natural aerosols or human - made pollutants... The glaciers therefore hold the memory of former climates and help to predict future environmental changes.

At the same time, understanding of climate change, especially the chronic problem of the role of clouds and aerosols, must be improved as well, he conceded.

In the tug of war, aerosols don't necessarily counter the impacts of climate change on sea ice (or the planet as a whole for that matter).

Therefore the dosage of administration has to change at it has been previously observed with other treatment modalities such as; inhaled insulin.35, 37 A major obstacle regarding the distribution of aerosol within the airways is atelectasis, tumor mass or pleural effusion.

Forcing changes of similar magnitude, due to water vapour variations, are measurable as regional temperature changes in Europe, see Philipona, but aerosol changes are not...

At EMSL, the GA helps users advance molecular science in areas such as aerosol formation, bioremediation, catalysis, climate change, hydrogen storage, and subsurface science.

These changes might influence interactions between the ocean and the atmosphere such as the air - sea gas exchange and the emission of sea - spray aerosols that can scatter solar radiation or contribute to the formation of clouds.

Thus to provide the clearest picture of the CO2 effect, we approximate the net future change of human - made non-CO2 forcings as zero and we exclude future changes of natural climate forcings, such as solar irradiance and volcanic aerosols.

In addition, both internal variability and aerosol forcing are likely to affect tropical storms in large part though changes in ocean temperature gradients (thereby changing ITCZ position and vertical shear), while greenhouse gases likely exert their influence by more uniformly changing ocean and tropospheric temperatures, so the physics of the problem may suggest this decomposition as more natural as well.

One type of inverse method uses the ranges of climate change fingerprint scaling factors derived from detection and attribution analyses that attempt to separate the climate response to greenhouse gas forcing from the response to aerosol forcing and often from natural forcing as well (Gregory et al., 2002a; Stott et al., 2006c; see also Section 9.4.1.4).

Then there are the tests of climate changes themselves: how does a model respond to the addition of aerosols in the stratosphere such as was seen in the Mt Pinatubo «natural experiment»?

Steve's predictions also extended to what he perceived as a big coming change to aerosol climatology.

And as for IPCC changing conclusions this has happened many times — Lindzen used to point to statements about upper tropospheric water vapour for instance that became less confident from the 1990, 1995 and 2001 reports, similarly uncertainty in aerosol indirect effects has clearly grown over time.]

The changes seen in the MSU 4 data (as even Roy Spencer has pointed out), are mainly due to ozone depletion (cooling) and volcanic eruptions (which warm the stratopshere because the extra aerosols absorb more heat locally).

That is, other feedbacks come into play — vegetation, ice sheets, aerosols, CH4 etc. will all change as a function a warming (or cooling), which are not included in the standard climate sensitivity definition.

All it demonstrates is that there is more than one causal factor, as is well known, with aerosols (from fossil fuels and volcanoes), land - use changes (through affecting CH$ and CO2 levels and albedo) and solar irradiance all playing a role.

But models are not tuned to the trends in surface temperature, and as Gavin noted before (at least for the GISS model), the aerosol amounts are derived from simulations using emissions data and direct effects determined by changes in concentrations.

As well as effective aerosol forcing of -1.2 W / m2 being mcuh stronger than the IPCC AR5 ERF of ~ -0.7 W / m2 over 1850 - 2000, the land use change effective forcing of -0.7 W / m2, arsign from a very high efficacy of 3.89, seems absurd to mAs well as effective aerosol forcing of -1.2 W / m2 being mcuh stronger than the IPCC AR5 ERF of ~ -0.7 W / m2 over 1850 - 2000, the land use change effective forcing of -0.7 W / m2, arsign from a very high efficacy of 3.89, seems absurd to mas effective aerosol forcing of -1.2 W / m2 being mcuh stronger than the IPCC AR5 ERF of ~ -0.7 W / m2 over 1850 - 2000, the land use change effective forcing of -0.7 W / m2, arsign from a very high efficacy of 3.89, seems absurd to me.

Among those choices as well as the rest including reducing fossil fuel combustion, deforestation, etc., one would want to find the cheapest / easiest, but also the most effective (the firmest grasp on that knob) and the safest / least negative side - effects - such as those you'd get from non - spatially / temporally - discrimating solar shades / cooling aerosols (precipitation changes, and?

Except that GHG forcing + cooling aerosol forcing results in less precipitation globally in general than reduced GHG forcing that produces the same global average temperature, as found in «Climate Change Methadone» elsewhere at RC.

If there was more natural variation in the past millenia, specifically due to solar changes, then that goes at the cost of the GHG / aerosol combination, as both are near impossible to distinguish from each other in the warming of the last halve century... Solar activity has never been as high, and for an as long period, as current in the past millenium (and even the past 8,000 years).

He is determined that something mysterious and unknown is causing recent climate change so as part of this he has to deny all prior forms of climate change including aerosols, CO2, solar etc..

Such factors include increased greenhouse gas concentrations associated with fossil fuel burning, sulphate aerosols produced as an industrial by - product, human - induced changes in land surface properties among other things.

Similarly, if the IPCC concludes that something is highly uncertain (such as the magnitude of changes in aerosol indirect effects), then there are no good grounds for assuming otherwise.

It hardly takes imagination to posit that while initial aerosol dimming might depress temperatures, the aerosols and atmosphere might react in ways that change heat balance in other directions as they disperse, through stratospheric chemistry, and the fact that, unsurprisingly, there is a difference in aerosol behaviour depending on day vs night (you can't reduce the sunlight that reaches the south pole on June 23rd....).

You can even go one better — if you ignore the fact that there are negative forcings in the system as well (cheifly aerosols and land use changes), the forcing from all the warming effects is larger still (~ 2.6 W / m2), and so the implied sensitivity even smaller!

Using your definition of «global» as opposed to «local» would think that all the aerosols would be included as they change the global temp.

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.).

Forcing changes of similar magnitude, due to water vapour variations, are measurable as regional temperature changes in Europe, see Philipona, but aerosol changes are not...

Recently I have been looking at the climate models collected in the CMIP3 archive which have been analysed and assessed in IPCC and it is very interesting to see how the forced changes — i.e. the changes driven the external factors such as greenhouse gases, tropospheric aerosols, solar forcing and stratospheric volcanic aerosols drive the forced response in the models (which you can see by averaging out several simulations of the same model with the same forcing)-- differ from the internal variability, such as associated with variations of the North Atlantic and the ENSO etc, which you can see by looking at individual realisations of a particular model and how it differs from the ensemble mean.

In their calculations, the direct tropo - spheric aerosol effect does not play a large net role, because the moderately absorbing aerosol assumption leads to an offset between its sunlight reflecting and absorbing properties insofar as the top of the atmosphere irradiance change is concerned.

One driver of temperatures in this region is the abundance and variability of ozone, but water vapor, volcanic aerosols, and dynamical changes such as the Quasi - Biennial Oscillation (QBO) are also significant; anthropogenic increases in other greenhouse gases such as carbon dioxide play a lesser but significant role in the lower stratosphere.

This is the portion of temperature change that is imposed on the ocean - atmosphere - land system from the outside and it includes contributions from anthropogenic increases in greenhouse gasses, aerosols, and land - use change as well as changes in solar radiation and volcanic aerosols.

In fact, they may do so more efficiently than more uniform temperature change; warming one hemisphere with respect to the other is an excellent way of pulling monsoonal circulations and oceanic ITCZs towards the warm hemisphere (the last few years have seen numerous studies of this response, relevant for ice ages and aerosol forcing as well as the response to high latitude internal variability; Chiang and Bitz, 2005 is one of the first to discuss this, in the ice age context; I'll try to return to this topic in a future post.)

I was told by one semi-expert climate scientist (someone who was in the process of changing fields to climate science from a different numerical modeling field, as so possibly still catching up) that although globally aerosols played the most important role in this period, there was also around the same time period (maybe beginning slightly earlier?

Pekka, place show me a Thermometer record which shows anything like the temperature change shown in that figures, as a result of volcanic aerosols.

Continued failure to quantify the specific origins of this large forcing is untenable, as knowledge of changing aerosol effects is needed to understand future climate change.

nevertheless, both states can coexist for a wide range of environmental conditions.5, 7 Aerosols, liquid or solid particles suspended in the atmosphere, serve as Cloud Condensation Nuclei (CCN) and therefore affect the concentration of activated cloud droplets.8 Changes in droplet concentration affect key cloud properties such as the time it takes for the onset of significant collision and coalescence between droplets, a process critical for rain formation.»