Sentences with phrase «stratospheric aerosols increased»

Several independent data sets show that stratospheric aerosols increased in abundance since 2000.

Not exact matches

China «could cause some decreases [in stratospheric aerosols] if that is the source,» Neely says, adding that growing SO2 emissions from India could also increase cooling if humans are the dominant cause of injecting aerosols into the atmosphere.

Determining whether humans or volcanoes explain more of the increase in stratospheric aerosols is the focus of ongoing research, says PhD candidate Ryan Neely of the University of Colorado, who contributed to the NOAA research.

There are multiple anthropogenic forcings that have quite different impacts (e.g. anthropogenic greenhouse gas increases, aerosols, land - use changes and, yes, stratospheric ozone depletion).

Possible reasons include increased oceanic circulation leading to increased subduction of heat into the ocean, higher than normal levels of stratospheric aerosols due to volcanoes during the past decade, incorrect ozone levels used as input to the models, lower than expected solar output during the last few years, or poorly modeled cloud feedback effects.

The potential risks around sulfate aerosol solar geoengineering include alteration of regional precipitation patterns, its effects on human health, and the potential damage to Earth's ozone layer by increased stratospheric sulfate particles.

Instead, they discuss new ways of playing around with the aerosol judge factor needed to explain why 20th - century warming is about half of the warming expected for increased in GHGs; and then expand their list of fudge factors to include smaller volcanos, stratospheric water vapor (published with no estimate of uncertainty for the predicted change in Ts), transfer of heat to the deeper ocean (where changes in heat content are hard to accurately measure), etc..

El Nino intensity and frequency increase during solar minima because negative NAO / AO increases, and major stratospheric volcanic aerosol events increase, also increasing El Nino conditions.

Possible attribution for MWP is a slight increase in TSI (increased solar luminosity and decreased volcanism / stratospheric aerosol loading).

Neely (2013 http://onlinelibrary.wiley.com/doi/10.1002/grl.50263/abstract): «Comparison of the model results to observations reveals that moderate volcanic eruptions, rather than anthropogenic influences, are the primary source of the observed increases in stratospheric aerosol.»

2) There are errors in the assumed forcings, such as: a) AR5 let stratospheric aerosol concentration go to zero after 2000 (a sure way to prod the models into higher predictions), but it actually increased for the next 10 years «probably due to a large number of small volcanic eruptions».

This study of course does not take away very different concerns related to stratospheric aerosol SRM geoengineering, like possible damage to the ozone layer [which in turn would be good news if you hate waiting for that spring tan] and the fact that allowing CO2 concentrations to keep rising presents other problems, like the necessity to never stop with the active process of SRM geoengineering, and increasing ecological damage caused by ocean acidification.

In particular, increases in the number of small particles (called aerosols) in the atmosphere regionally offset and mask the greenhouse effect, and stratospheric ozone depletion contributes to cooling of the upper troposphere and stratosphere.fr2], fr3]

I believe it, rather than the enhanced solar forcing, is considered to be the primary reason for the rapid increase in temperature during that interval, just as the reintroduction of stratospheric aerosols is a significant factor in the slight cooling from the mid 1940s to the late 1960s.

[note] In this context it intrigues me that those who advocate for stratospheric aerosol injection (SAI) tend to ignore the possibility that the possible termination effect would increase net risk from greenhouse gas emissions, and the deployment of SAI should therefore (in risk adjustment terms) justify accelerated mitigation rather than reduced mitigation.

Together with potentially increased tropical aerosol concentrations, they might even have an impact on the stratospheric background AOD currently (Vernier et al..

They point out that «recent studies using ground - based lidar and satellite instruments document an increase in stratospheric aerosol of 4 — 10 percent per year from 2000 to 2010.»

Recently, there have been debates about the slowing of the warming rates since 2005, with explanations (44 ⇓ — 46) ranging from increases in stratospheric water vapor and background aerosol to increased coal burning in the emergent economy of China of the past 20 y.

Forster et al. (2007) described four mechanisms by which volcanic forcing influences climate: RF due to aerosol — radiation interaction; differential (vertical or horizontal) heating, producing gradients and changes in circulation; interactions with other modes of circulation, such as El Niño - Southern Oscillation (ENSO); and ozone depletion with its effects on stratospheric heating, which depends on anthropogenic chlorine (stratospheric ozone would increase with a volcanic eruption under low - chlorine conditions).

Figure 4 shows that changes in several external forcings over the ETCW could be important, such as: a greenhouse gas increase, a small change in solar irradiance, and a reduction in stratospheric aerosols associated with reduced volcanic activity.