Volcanic contribution to decadal changes in tropospheric temperature




Despite continued growth in atmospheric levels of greenhouse gases, global mean surface and tropospheric temperatures have shown slower warming since 1998 than previously1, 2, 3, 4, 5. Possible explanations for the slow-down include internal climate variability3, 4, 6, 7, external cooling influences1, 2, 4, 8, 9, 10, 11 and observational errors12, 13. Several recent modelling studies have examined the contribution of early twenty-first-century volcanic eruptions1, 2, 4, 8 to the muted surface warming. Here we present a detailed analysis of the impact of recent volcanic forcing on tropospheric temperature, based on observations as well as climate model simulations. We identify statistically significant correlations between observations of stratospheric aerosol optical depth and satellite-based estimates of both tropospheric temperature and short-wave fluxes at the top of the atmosphere. We show that climate model simulations without the effects of early twenty-first-century volcanic eruptions overestimate the tropospheric warming observed since 1998. In two simulations with more realistic volcanic influences following the 1991 Pinatubo eruption, differences between simulated and observed tropospheric temperature trends over the period 1998 to 2012 are up to 15% smaller, with large uncertainties in the magnitude of the effect. To reduce these uncertainties, better observations of eruption-specific properties of volcanic aerosols are needed, as well as improved representation of these eruption-specific properties in climate model simulations.

At a glance

Figures

First | 1-4 of 4 | Last
left
  1. Modelled and observed near-global (82.5[deg] N-70[deg] S) monthly mean TLT anomalies before and after statistical removal of ENSO and volcano signals.
    Figure 1
  2. Effect of recent volcanic eruptions on atmospheric temperature.
    Figure 2
  3. Statistical significance of observed tropical (20[deg] N-20[deg] S) climate signals after late twentieth- and early twenty-first-century volcanic eruptions.
    Figure 3
  4. Behaviour of overlapping 10-year trends in the /`ENSO removed/' near-global (82.5[deg] N-70[deg] S) TLT data.
    Figure 4
right
  1. Solomon, S. et al. The persistently variable ‘background’ stratospheric aerosol layer and global climate change. Science 333, 866–870 (2011).
  2. Fyfe, J. C., von Salzen, K., Cole, J. N. S., Gillett, N. P. & Vernier, J-P. Surface response to stratospheric aerosol changes in a coupled atmosphere–ocean model. Geophys. Res. Lett.40, 584–588 (2013).
  3. Santer, B. D. et al. Separating signal and noise in atmospheric temperature changes: The importance of timescale. J. Geophys. Res. 116, D22105 (2011).
  4. Fyfe, J. C., Gillett, N. P. & Zwiers, F. W. Overestimated global warming over the past 20 years. Nature Clim. Change 3, 767–769 (2013).
  5. Santer, B. D. et al. Identifying human influences on atmospheric temperature. Proc. Natl. Acad. Sci. USA 110, 26–33 (2013).
  6. Meehl, G. A., Arblaster, J. M., Fasullo, J. T., Hu, A. & Trenberth, K. E. Model-based evidence of deep-ocean heat uptake during surface-temperature hiatus periods. Nature Clim. Change1, 360–364 (2011).
  7. Kosaka, K. & Xie, S-P. Recent global-warming hiatus tied to equatorial Pacific surface cooling.Nature 501, 403–407 (2013).
  8. Haywood, J. M., Jones, A. & Jones, G. S. The impact of volcanic eruptions in the period 2000-2013 on global mean temperature trends evaluated in the HadGEM2-ES climate model.Atmos. Sci. Lett. (2013)doi:10.1002/asl2.471
  9. Kopp, G. & Lean, J. L. A new, lower value of total solar irradiance: Evidence and climate significance. Geophys. Res. Lett. 38, L01706 (2011).
  10. Solomon, S. et al. Contributions of stratospheric water vapour to decadal changes in the rate of global warming. Science 327, 1219–1223 (2010).
  11. Shindell, D. T. et al. Radiative forcing in the ACCMIP historical and future climate simulations.Atmos. Chem. Phys. 13, 2939–2974 (2013).
  12. Morice, C. P., Kennedy, J. J., Rayner, N. A. & Jones, P. D. Quantifying uncertainties in global and regional temperature change using an ensemble of observational estimates: The HadCRUT4 data set. J. Geophys. Res. 117, D08101 (2012).
  13. Mears, C., Wentz, F. J., Thorne, P. & Bernie, D. Assessing uncertainty in estimates of atmospheric temperature changes from MSU and AMSU using a Monte-Carlo technique. J. Geophys. Res. 116, D08112 (2011).
  14. Christy, J. R., Norris, W. B., Spencer, R. W. & Hnilo, J. J. Tropospheric temperature change since 1979 from tropical radiosonde and satellite measurements. J. Geophys. Res. 112,D06102 (2007).
  15. Cowtan, K. & Way, R. G. Coverage bias in the HadCRUT4 temperature series and its impact on recent temperature trends, Quart. J. Roy. Met. Soc.http://dx.doi.org/10.1002/qj.2297 (in the press)
  16. Taylor, K. E., Stouffer, R. J. & Meehl, G. A. An overview of CMIP5 and the experiment design.Bull. Amer. Meteor. Soc. (2012)doi:10.1175/BAMS-D-11-00094.1
  17. Robock, A. Volcanic eruptions and climate. Rev. Geophys. 38, 191–219 (2000).
  18. Sato, M., Hansen, J. E., McCormick, M. P. & Pollack, J. B. Stratospheric aerosol optical depth, 1850–1990. J. Geophys. Res. 98, 22987–22994 (1993).
  19. Ramaswamy, V. et al. Anthropogenic and natural influences in the evolution of lower stratospheric cooling. Science 311, 1138–1141 (2006).
  20. Wigley, T M L., Ammann, C. M., Santer, B. D. & Raper, S C B. The effect of climate sensitivity on the response to volcanic forcing. J. Geophys. Res. 110, D09107 (2005).
  21. Santer, B. D. et al. Accounting for the effects of volcanoes and ENSO in comparisons of modeled and observed temperature trends. J. Geophys. Res. 106, 28033–28059 (2001).
  22. Thompson, D W J., Wallace, J. M., Jones, P. D. & Kennedy, J. J. Identifying signatures of natural climate variability in time series of global-mean surface temperature: Methodology and insights. J. Clim. 22, 6120–6141 (2009).
  23. Smith, T. M., Reynolds, R. W., Peterson, T. C. & Lawrimore, J. Improvements to NOAA’s historical merged land-ocean surface temperature analysis (1880–2006). J. Clim. 21,2283–2296 (2008).
  24. Vernier, J.-P. et al. Major influence of tropical volcanic eruptions on the stratospheric aerosol layer during the last decade. Geophys. Res. Lett. 38, L12807 (2011).
  25. Neely III, R. R. et al. Recent anthropogenic increases in SO2 from Asia have minimal impact on stratospheric aerosol. Geophys. Res. Lett. 40 (2013)doi:10.1002grl.50263
  26. Loeb, N. G. et al. Towards optimal closure of the earth’s top-of-atmosphere radiation budget.J. Climate 22, 748–766 (2009).
  27. Muller, R.http://www.nytimes.com/2013/09/26/opinion/a-pause-not-an-end-to-warming.html?_r=0
  28. Christy, J. R. Testimony in Hearing before the Subcommittee on Energy and Power, Committee on Energy and Commerce, House of Representatives, March 8, 2011.http://republicans.energycommerce.house.gov/Media/file/Hearings/Energy/030811/Christy.pdf
  29. Hassler, B. et al. Comparison of three vertically resolved ozone data sets: Climatology, trends and radiative forcings. Atmos. Chem. Phys. 13, 5533–5550 (2013).
  30. Eyring, V. et al. Long-term ozone changes and associated climate impacts in CMIP5 simulations. J. Geophys. Res. 118, 5029–5060 (2013).
  31. http://www.nature.com/ngeo/journal/v7/n3/full/ngeo2098.html

Comments

Post a Comment

Popular posts from this blog

Claim: Decrease in air pollution associated with decrease in respiratory symptoms among children False. Since air quality is not associated with childhood asthma in the first place.

Image
   The media release is below. One of the most important things you can do to manage your asthma is to work with your healthcare provider to identify and minimize your exposure to your asthma triggers. Triggers are allergens, irritants, or conditions that cause your asthma symptoms to worsen. It’s important to know what triggers your asthma symptoms. Triggers vary from person to person, so you should learn which specific ones affect you. While it may be impossible to avoid every single asthma trigger, there may be things you can do to help. Being able to identify and avoid your triggers is important. Below you’ll find tips on dealing with various types of asthma triggers. If you are able to reduce your exposure to some of these triggers but you still experience asthma symptoms, talk with your healthcare provider. Select the triggers below to find out more. ...
Read more

Deniers Need Not Apply: National Academy of Sciences says climate modelers should be ‘accredited’

From the new National Academy of Sciences report on climate modeling: Climate information is already being provided by a number of public and private entities in various capacities, and there have been numerous other calls for the provision of more extensive government-run climate information services. The committee chose to not weigh in on the debate about the appropriate role for the federal government in providing climate services. Rather, the committee notes the need for qualified individuals who can provide credible information to end users based on current climate models, wherever they work. To address this need, the committee recommends developing a national education and accreditation program for “climate model interpreters” who can take technical findings and output from climate models, including quantified uncertainties, and use them in a diverse range of private- and public-sector applications. Read the report. http://junkscience.com/2013/09/13/deniers-need-not-ap...
Read more