Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Vegetation feedbacks during drought exacerbate ozone air pollution extremes in Europe

A Publisher Correction to this article was published on 17 June 2020

This article has been updated

Abstract

Reducing surface ozone to meet the European Union’s target for human health has proven challenging despite stringent controls on ozone precursor emissions over recent decades. The most extreme ozone pollution episodes are linked to heatwaves and droughts, which are increasing in frequency and intensity over Europe, with severe impacts on natural and human systems. Here, we use observations and Earth system model simulations for the period 1960–2018 to show that ecosystem–atmosphere interactions, especially reduced ozone removal by water-stressed vegetation, exacerbate ozone air pollution over Europe. These vegetation feedbacks worsen peak ozone episodes during European mega-droughts, such as the 2003 event, offsetting much of the air quality improvements gained from regional emissions controls. As the frequency of hot and dry summers is expected to increase over the coming decades, this climate penalty could be severe and therefore needs to be considered when designing clean air policy in the European Union.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Correlations between ozone air quality and temperature in Europe.
Fig. 2: Changes in European ozone air quality.
Fig. 3: Reduced ozone removal by forests under drought stress.
Fig. 4: Declining ozone removal by water-stressed vegetation in a warming climate.
Fig. 5: Reduced uptake by plants worsens ozone air pollution extremes.
Fig. 6: Ecosystem–atmosphere interactions exacerbate climate penalty on ozone extremes.

Similar content being viewed by others

Data availability

Ozone flux measurements, the ozone climate penalty factors derived from observations and model simulations generated in this study are archived at a public data repository at NOAA GFDL (ftp://data1.gfdl.noaa.gov/users/Meiyun.Lin/Nature2020/). Ozone deposition velocities from LM4.0 are archived at ftp://data1.gfdl.noaa.gov/users/Meiyun.Lin/GBC2019/GFDL‐LM4/. Source data for Figs. 1–6 and Extended Data Figs. 1–10 are provided with the paper.

Code availability

The computer code for the standard versions of GFDL’s atmospheric and land models is publicly available at https://www.gfdl.noaa.gov/atmospheric-model/. Other codes used in this study are available from the corresponding author upon reasonable request.

Change history

References

  1. Vestreng, V. et al. Evolution of NOx emissions in Europe with focus on road transport control measures. Atmos. Chem. Phys. 9, 1503–1520 (2009).

    CAS  Google Scholar 

  2. Directive 2008/50/EC of the European Parliament and of the Council of 21 May 2008 on Ambient Air Quality and Cleaner air for Europe (European Union, 2008).

  3. Communication from the Commission to the Council, the European Parliament, the European Economic and Social Committee and the Committee of the Regions—A Clean Air Programme for Europe (European Commission, 2013).

  4. Directive 2016/2284/EC of the European Parliament and of the Council of 14 December 2016 on the Reduction of National Emissions of Certain Atmospheric Pollutants, Amending Directive 2003/35/EC and Repealing Directive 2001/81/EC (European Union, 2016).

  5. Granier, C. et al. Evolution of anthropogenic and biomass burning emissions of air pollutants at global and regional scales during the 1980–2010 period. Climatic Change 109, 163–190 (2011).

    CAS  Google Scholar 

  6. Monks, P. S. et al. Tropospheric ozone and its precursors from the urban to the global scale from air quality to short-lived climate forcer. Atmos. Chem. Phys. 15, 8889–8973 (2015).

    CAS  Google Scholar 

  7. Hoesly, R. M. et al. Historical (1750–2014) anthropogenic emissions of reactive gases and aerosols from the Community Emissions Data System (CEDS). Geosci. Model Dev. 11, 369–408 (2018).

    CAS  Google Scholar 

  8. Georgoulias, A. K., van der A., R. J., Stammes, P., Boersma, K. F. & Eskes, H. J. Trends and trend reversal detection in 2 decades of tropospheric NO2 satellite observations. Atmos. Chem. Phys. 19, 6269–6294 (2019).

    CAS  Google Scholar 

  9. Logan, J. A. et al. Changes in ozone over Europe: analysis of ozone measurements from sondes, regular aircraft (MOZAIC) and alpine surface sites. J. Geophys. Res. 117, D09301 (2012).

    Google Scholar 

  10. Parrish, D. D. et al. Long-term changes in lower tropospheric baseline ozone concentrations at northern mid-latitudes. Atmos. Chem. Phys. 12, 11485–11504 (2012).

    CAS  Google Scholar 

  11. Air Quality in Europe—2018 Report Report No. 12/2018 (European Environment Agency, 2018).

  12. Exceedance of Air Quality Standards in Urban Areas (European Environment Agency, 2019).

  13. Lelieveld, J. & Dentener, F. J. What controls tropospheric ozone? J. Geophys. Res. 105, 3531–3551 (2000).

    CAS  Google Scholar 

  14. Koumoutsaris, S. & Bey, I. Can a global model reproduce observed trends in summertime surface ozone levels? Atmos. Chem. Phys. 12, 6983–6998 (2012).

    CAS  Google Scholar 

  15. Colette, A. et al. Air quality trends in Europe over the past decade: a first multi-model assessment. Atmos. Chem. Phys. 11, 11657–11678 (2011).

    CAS  Google Scholar 

  16. Fusco, A. C. & Logan, J. A. Analysis of 1970–1995 trends in tropospheric ozone at Northern Hemisphere midlatitudes with the GEOS-CHEM model. J. Geophys. Res. 108, 4449 (2003).

    Google Scholar 

  17. Wild, O. et al. Modelling future changes in surface ozone: a parameterized approach. Atmos. Chem. Phys. 12, 2037–2054 (2012).

    CAS  Google Scholar 

  18. Lamarque, J. F. et al. Historical (1850–2000) gridded anthropogenic and biomass burning emissions of reactive gases and aerosols: methodology and application. Atmos. Chem. Phys. 10, 7017–7039 (2010).

    CAS  Google Scholar 

  19. Parrish, D. D. et al. Long-term changes in lower tropospheric baseline ozone concentrations: comparing chemistry–climate models and observations at northern midlatitudes. J. Geophys. Res. 119, 5719–5736 (2014).

    CAS  Google Scholar 

  20. Lin, M. et al. Revisiting the evidence of increasing springtime ozone mixing ratios in the free troposphere over western North America. Geophys. Res. Lett. 42, 8719–8728 (2015).

    CAS  Google Scholar 

  21. Lin, M., Horowitz, L. W., Payton, R., Fiore, A. M. & Tonnesen, G. US surface ozone trends and extremes from 1980 to 2014: quantifying the roles of rising Asian emissions, domestic controls, wildfires, and climate. Atmos. Chem. Phys. 17, 2943–2970 (2017).

    CAS  Google Scholar 

  22. Fischer, E. M., Seneviratne, S. I., Luthi, D. & Schar, C. Contribution of land–atmosphere coupling to recent European summer heat waves. Geophys. Res. Lett. 34, L06707 (2007).

    Google Scholar 

  23. Seneviratne, S. I., Luthi, D., Litschi, M. & Schar, C. Land–atmosphere coupling and climate change in Europe. Nature 443, 205–209 (2006).

    CAS  Google Scholar 

  24. Hirschi, M. et al. Observational evidence for soil-moisture impact on hot extremes in southeastern Europe. Nat. Geosci. 4, 17–21 (2011).

    CAS  Google Scholar 

  25. Miralles, D. G., Teuling, A. J., van Heerwaarden, C. C. & de Arellano, J. V. G. Mega-heatwave temperatures due to combined soil desiccation and atmospheric heat accumulation. Nat. Geosci. 7, 345–349 (2014).

    CAS  Google Scholar 

  26. Rasmijn, L. M. et al. Future equivalent of 2010 Russian heatwave intensified by weakening soil moisture constraints. Nat. Clim. Change 8, 381–385 (2018).

    Google Scholar 

  27. Samaniego, L. et al. Anthropogenic warming exacerbates European soil moisture droughts. Nat. Clim. Change 8, 421–426 (2018).

    Google Scholar 

  28. Teuling, A. J. Climate hydrology: a hot future for European droughts. Nat. Clim. Change 8, 364–365 (2018).

    Google Scholar 

  29. Gerosa, G. et al. Comparison of seasonal variations of ozone exposure and fluxes in a Mediterranean holm oak forest between the exceptionally dry 2003 and the following year. Environ. Pollut. 157, 1737–1744 (2009).

    CAS  Google Scholar 

  30. Fowler, D. et al. Atmospheric composition change: ecosystems–atmosphere interactions. Atmos. Environ. 43, 5193–5267 (2009).

    CAS  Google Scholar 

  31. Rydsaa, J. H., Stordal, F., Gerosa, G., Finco, A. & Hodnebrog, O. Evaluating stomatal ozone fluxes in WRF-Chem: comparing ozone uptake in Mediterranean ecosystems. Atmos. Environ. 143, 237–248 (2016).

    CAS  Google Scholar 

  32. Hardacre, C., Wild, O. & Emberson, L. An evaluation of ozone dry deposition in global scale chemistry climate models. Atmos. Chem. Phys. 15, 6419–6436 (2015).

    CAS  Google Scholar 

  33. Silva, S. J. & Heald, C. L. Investigating dry deposition of ozone to vegetation. J. Geophys. Res. Atmos. 123, 559–573 (2018).

    CAS  Google Scholar 

  34. Morgenstern, O. et al. Review of the global models used within phase 1 of the Chemistry–Climate Model Initiative (CCMI). Geosci. Model Dev. 10, 639–671 (2017).

    Google Scholar 

  35. Wesely, M. L. Parameterization of surface resistances to gaseous dry deposition in regional-scale numerical models. Atmos. Environ. 23, 1293–1304 (1989).

    CAS  Google Scholar 

  36. Kavassalis, S. C. & Murphy, J. G. Understanding ozone–meteorology correlations: a role for dry deposition. Geophys. Res. Lett. 44, 2922–2931 (2017).

    Google Scholar 

  37. Andersson, C. & Engardt, M. European ozone in a future climate: importance of changes in dry deposition and isoprene emissions. J. Geophys. Res. Atmos. 115, D02303 (2010).

    Google Scholar 

  38. Emberson, L. D., Kitwiroon, N., Beevers, S., Buker, P. & Cinderby, S. Scorched Earth: how will changes in the strength of the vegetation sink to ozone deposition affect human health and ecosystems? Atmos. Chem. Phys. 13, 6741–6755 (2013).

    Google Scholar 

  39. Huang, L., McDonald-Buller, E. C., McGaughey, G., Kimura, Y. & Allen, D. T. The impact of drought on ozone dry deposition over eastern Texas. Atmos. Environ. 127, 176–186 (2016).

    CAS  Google Scholar 

  40. Lin, M. et al. Sensitivity of ozone dry deposition to ecosystem–atmosphere interactions: a critical appraisal of observations and simulations. Glob. Biogeochem. Cycles 33, 1264–1288 (2019).

    CAS  Google Scholar 

  41. Clifton, O. E., Fiore, A. M., Munger, J. W. & Wehr, R. Spatiotemporal controls on observed daytime ozone deposition velocity over northeastern U.S. forests during summer. J. Geophys. Res. Atmos. 124, 5612–5628 (2019).

    CAS  Google Scholar 

  42. Lombardozzi, D., Levis, S., Bonan, G., Hess, P. G. & Sparks, J. P. The influence of chronic ozone exposure on global carbon and water cycles. J. Clim. 28, 292–305 (2015).

    Google Scholar 

  43. Sadiq, M., Tai, A. P. K., Lombardozzi, D. & Martin, M. V. Effects of ozone–vegetation coupling on surface ozone air quality via biogeochemical and meteorological feedbacks. Atmos. Chem. Phys. 17, 3055–3066 (2017).

    CAS  Google Scholar 

  44. Bloomer, B. J., Stehr, J. W., Piety, C. A., Salawitch, R. J. & Dickerson, R. R. Observed relationships of ozone air pollution with temperature and emissions. Geophys. Res. Lett. 36, L09803 (2009).

    Google Scholar 

  45. Rasmussen, D. J. et al. Surface ozone–temperature relationships in the eastern US: a monthly climatology for evaluating chemistry–climate models. Atmos. Environ. 47, 142–153 (2012).

    CAS  Google Scholar 

  46. Paulot, F. et al. Representing sub-grid scale variations in nitrogen deposition associated with land use in a global Earth system model: implications for present and future nitrogen deposition fluxes over North America. Atmos. Chem. Phys. 18, 17963–17978 (2018).

    CAS  Google Scholar 

  47. Lin, M., Horowitz, L. W., Oltmans, S. J., Fiore, A. M. & Fan, S. Tropospheric ozone trends at Mauna Loa Observatory tied to decadal climate variability. Nat. Geosci. 7, 136–143 (2014).

    CAS  Google Scholar 

  48. Jarvis, P. G. Interpretation of variations in leaf water potential and stomatal conductance found in canopies in field. Phil. Trans. R. Soc. Lond. B 273, 593–610 (1976).

    CAS  Google Scholar 

  49. von Schneidemesser, E., Monks, P. S. & Plass-Duelmer, C. Global comparison of VOC and CO observations in urban areas. Atmos. Environ. 44, 5053–5064 (2010).

    CAS  Google Scholar 

  50. Barriopedro, D., Fischer, E. M., Luterbacher, J., Trigo, R. & Garcia-Herrera, R. The hot summer of 2010: redrawing the temperature record map of Europe. Science 332, 220–224 (2011).

    CAS  Google Scholar 

  51. Russo, S., Sillmann, J. & Fischer, E. M. Top ten European heatwaves since 1950 and their occurrence in the coming decades. Environ. Res. Lett. 10, 124003 (2015).

    Google Scholar 

  52. Fischer, E. M., Seneviratne, S. I., Vidale, P. L., Luthi, D. & Schar, C. Soil moisture–atmosphere interactions during the 2003 European summer heat wave. J. Clim. 20, 5081–5099 (2007).

    Google Scholar 

  53. Sheffield, J. & Wood, E. F. Drought: Past Problems and Future Scenarios (Earthscan, 2011).

  54. Mora, C. et al. Global risk of deadly heat. Nat. Clim. Change 7, 501–506 (2017).

    Google Scholar 

  55. Robine, J. M. et al. Death toll exceeded 70,000 in Europe during the summer of 2003. C. R. Biol. 331, 171–178 (2008).

    Google Scholar 

  56. Dear, K., Ranmuthugala, G., Kjellstrom, T., Skinner, C. & Hanigan, I. Effects of temperature and ozone on daily mortality during the August 2003 heat wave in France. Arch. Environ. Occup. Health 60, 205–212 (2005).

    Google Scholar 

  57. Christidis, N., Jones, G. S. & Stott, P. A. Dramatically increasing chance of extremely hot summers since the 2003 European heatwave. Nat. Clim. Change 5, 46–50 (2015).

    Google Scholar 

  58. Horton, D. E. et al. Contribution of changes in atmospheric circulation patterns to extreme temperature trends. Nature 522, 465–469 (2015).

    CAS  Google Scholar 

  59. Jacob, D. J. & Winner, D. A. Effect of climate change on air quality. Atmos. Environ. 43, 51–63 (2009).

    CAS  Google Scholar 

  60. Fiore, A. M., Naik, V. & Leibensperger, E. M. Air quality and climate connections. J. Air Waste Manage. Assoc. 65, 645–685 (2015).

    CAS  Google Scholar 

  61. Sillman, S. & Samson, F. J. Impact of temperature on oxidant photochemistry in urban, polluted rural and remote environments. J. Geophys. Res. Atmos. 100, 11497–11508 (1995).

    CAS  Google Scholar 

  62. Pusede, S. E., Steiner, A. L. & Cohen, R. C. Temperature and recent trends in the chemistry of continental surface ozone. Chem. Rev. 115, 3898–3918 (2015).

    CAS  Google Scholar 

  63. Guenther, A. B. et al. The Model of Emissions of Gases and Aerosols from Nature version 2.1 (MEGAN2.1): an extended and updated framework for modeling biogenic emissions. Geosci. Model Dev. 5, 1471–1492 (2012).

    Google Scholar 

  64. Yienger, J. J. & Levy, H. Empirical-model of global soil-biogenic NOx emissions. J. Geophys. Res. Atmos. 100, 11447–11464 (1995).

    CAS  Google Scholar 

  65. Hudman, R. C., Russell, A. R., Valin, L. C. & Cohen, R. C. Interannual variability in soil nitric oxide emissions over the United States as viewed from space. Atmos. Chem. Phys. 10, 9943–9952 (2010).

    CAS  Google Scholar 

  66. Oikawa, P. Y. et al. Unusually high soil nitrogen oxide emissions influence air quality in a high-temperature agricultural region. Nat. Commun. 6, 8753 (2015).

    CAS  Google Scholar 

  67. Jaffe, D. & Wigder, N. L. Ozone production from wildfires: a critical review. Atmos. Environ. 51, 1–10 (2012).

    CAS  Google Scholar 

  68. Demetillo, M. A. G. et al. Observing severe drought influences on ozone air pollution in California. Environ. Sci. Technol. 53, 4695–4706 (2019).

    CAS  Google Scholar 

  69. Begueria, S., Vicente-Serrano, S. M., Reig, F. & Latorre, B. Standardized Precipitation Evapotranspiration Index (SPEI) revisited: parameter fitting, evapotranspiration models, tools, datasets and drought monitoring. Int. J. Clim. 34, 3001–3023 (2014).

    Google Scholar 

  70. Sheffield, J., Goteti, G. & Wood, E. F. Development of a 50-year high-resolution global dataset of meteorological forcings for land surface modeling. J. Clim. 19, 3088–3111 (2006).

    Google Scholar 

  71. Hoerling, M. et al. On the increased frequency of Mediterranean drought. J. Clim. 25, 2146–2161 (2012).

    Google Scholar 

  72. Seager, R. et al. Climate variability and change of Mediterranean-type climates. J. Clim. 32, 2887–2915 (2019).

    Google Scholar 

  73. Dai, A. G. Increasing drought under global warming in observations and models. Nat. Clim. Change 3, 52–58 (2013).

    Google Scholar 

  74. Sheffield, J., Wood, E. F. & Roderick, M. L. Little change in global drought over the past 60 years. Nature 491, 435–438 (2012).

    CAS  Google Scholar 

  75. Milly, P. C. D. & Dunne, K. A. Potential evapotranspiration and continental drying. Nat. Clim. Change 6, 946–949 (2016).

    Google Scholar 

  76. Derwent, R. G., Simmonds, P. G., Manning, A. J. & Spain, T. G. Trends over a 20-year period from 1987 to 2007 in surface ozone at the atmospheric research station, Mace Head, Ireland. Atmos. Environ. 41, 9091–9098 (2007).

    CAS  Google Scholar 

  77. Zhang, Y. H., Seidel, D. J. & Zhang, S. D. Trends in planetary boundary layer height over Europe. J. Clim. 26, 10071–10076 (2013).

    Google Scholar 

  78. Konovalov, I. B., Beekmann, M., Kuznetsova, I. N., Yurova, A. & Zvyagintsev, A. M. Atmospheric impacts of the 2010 Russian wildfires: integrating modelling and measurements of an extreme air pollution episode in the Moscow region. Atmos. Chem. Phys. 11, 10031–10056 (2011).

    CAS  Google Scholar 

  79. Porter, W. C., Heald, C. L., Cooley, D. & Russell, B. Investigating the observed sensitivities of air-quality extremes to meteorological drivers via quantile regression. Atmos. Chem. Phys. 15, 10349–10366 (2015).

    CAS  Google Scholar 

  80. Climate Change and the US Energy Sector: Regional Vulnerabilities and Resilience Solutions (DOE, 2015).

  81. Report from the Commission to the European Parliament, the European Economic and Social Committee and the Committee of the Regions—“The First Clean Air Outlook” (European Commission, 2018).

  82. European Monitoring and Evaluation Program (EMEP) Measurement Data (EMEP, 2019); https://projects.nilu.no/CCC/emepdata.html

  83. European Air Quality Portal (European Environment Agency, 2020); http://discomap.eea.europa.eu/map/fme/AirQualityExport.htm

  84. Schultz, M. G. et al. Tropospheric ozone assessment report: database and metrics data of global surface ozone observations. Elementa 5, 58 (2017).

    Google Scholar 

  85. Harris, I., Jones, P. D., Osborn, T. J. & Lister, D. H. Updated high-resolution grids of monthly climatic observations—the CRU TS3.10 Dataset. Int. J. Clim. 34, 623–642 (2014).

    Google Scholar 

  86. Donat, M. et al. Global land-based datasets for monitoring climatic extremes. Bull. Amer. Meteor. Soc. 94, 997–1006 (2013).

    Google Scholar 

  87. Pilegaard, K., Jensen, N. O. & Hummelshoj, P. Seasonal and diurnal variation in the deposition velocity of ozone over a spruce forest in Denmark. Water Air Soil Pollut. 85, 2223–2228 (1995).

    CAS  Google Scholar 

  88. Webb, E. K., Pearman, G. I. & Leuning, R. Correction of flux measurements for density effects due to heat and water vapour transfer. Q. J. R. Meteorol. Soc. 106, 85–100 (1980).

    Google Scholar 

  89. Vickers, D. & Mahrt, L. Quality control and flux sampling problems for tower and aircraft data. J. Atmos. Ocean Technol. 14, 512–526 (1997).

    Google Scholar 

  90. Shevliakova, E. et al. Carbon cycling under 300 years of land use change: importance of the secondary vegetation sink. Global Biogeochem. Cycles 23, Gb2022 (2009).

    Google Scholar 

  91. Malyshev, S., Shevliakova, E., Stouffer, R. J. & Pacala, S. W. Contrasting local versus regional effects of land-use-change-induced heterogeneity on historical climate: analysis with the GFDL Earth system model. J. Clim. 28, 5448–5469 (2015).

    Google Scholar 

  92. Zhao, M. et al. The GFDL global atmosphere and land model AM4.0/LM4.0:2. Model description, sensitivity studies, and tuning strategies. J. Adv. Model. Earth Syst. 10, 735–769 (2018).

    Google Scholar 

  93. Zhao, M. et al. The GFDL global atmosphere and land model AM4.0/LM4.0:1. Simulation characteristics with prescribed SSTs. J. Adv. Model. Earth Syst. 10, 691–734 (2018).

    Google Scholar 

  94. Hurtt, G. C. et al. Harmonization of land-use scenarios for the period 1500–2100: 600 years of global gridded annual land-use transitions, wood harvest, and resulting secondary lands. Climatic Change 109, 117–161 (2011).

    Google Scholar 

  95. Zhang, L. M., Brook, J. R. & Vet, R. A revised parameterization for gaseous dry deposition in air-quality models. Atmos. Chem. Phys. 3, 2067–2082 (2003).

    CAS  Google Scholar 

  96. Massman, W. J. Toward an ozone standard to protect vegetation based on effective dose: a review of deposition resistances and a possible metric. Atmos. Environ. 38, 2323–2337 (2004).

    CAS  Google Scholar 

  97. Weng, E. S. et al. Scaling from individual trees to forests in an Earth system modeling framework using a mathematically tractable model of height-structured competition. Biogeosciences 12, 2655–2694 (2015).

    Google Scholar 

  98. Milly, P. C. D. et al. An enhanced model of land water and energy for global hydrologic and Earth-system studies. J. Hydrometeorol. 15, 1739–1761 (2014).

    Google Scholar 

  99. Lammertsma, E. I. et al. Global CO2 rise leads to reduced maximum stomatal conductance in Florida vegetation. Proc. Natl Acad. Sci. USA 108, 4035–4040 (2011).

    CAS  Google Scholar 

  100. Lin, M. et al. Transport of Asian ozone pollution into surface air over the western United States in spring. J. Geophys. Res. 117, D00V07 (2012).

    Google Scholar 

  101. Lin, M. et al. Climate variability modulates western US ozone air quality in spring via deep stratospheric intrusions. Nat. Commun. 6, 7105 (2015).

    CAS  Google Scholar 

  102. van der Werf, G. R. et al. Global fire emissions estimates during 1997–2016. Earth Syst. Sci. Data 9, 697–720 (2017).

    Google Scholar 

  103. Horowitz, L. W. Past, present, and future concentrations of tropospheric ozone and aerosols: methodology, ozone evaluation, and sensitivity to aerosol wet removal. J. Geophys. Res. 111, D22211 (2006).

    Google Scholar 

  104. Hassler, B. et al. Analysis of long-term observations of NOx and CO in megacities and application to constraining emissions inventories. Geophys. Res. Lett. 43, 9920–9930 (2016).

    CAS  Google Scholar 

  105. Duncan, B. N. et al. A space-based, high-resolution view of notable changes in urban NOx pollution around the world (2005–2014). J. Geophys. Res. 121, 976–996 (2016).

    CAS  Google Scholar 

Download references

Acknowledgements

This report was prepared by M. Lin under awards NA14OAR4320106 and NA18OAR4320123 from the National Oceanic and Atmospheric Administration (NOAA), US Department of Commerce. The statements, findings, conclusions and recommendations are those of the authors and do not necessarily reflect the views of NOAA. We thank GFDL internal reviewers, K. Dixon and J. Krasting, for constructive comments, which have helped to strengthen the article.

Author information

Authors and Affiliations

Authors

Contributions

M.L. conceived this study, performed the model experiments and analysis, and wrote the article. M.L., L.W.H. and E.S. designed the model experiments. Y.X. performed the ozone–temperature regression analysis under the supervision of M.L. F.P., M.L., S.M. and E.S. developed the dry deposition scheme. A.F., G.G. and K.P. provided ozone flux measurements. D.K. provided surface ozone measurements at Hohenpeissenberg. All authors contributed to discussions and edited the manuscript.

Corresponding author

Correspondence to Meiyun Lin.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Climate Change thanks Elena McDonald-Buller and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 Ozone-temperature relationships.

Scatter plots of observed June-August mean MDA8 ozone anomalies (relative to 19802000) at Hohenpeissenberg and Zugspitze and observed June-August mean Tmax anomalies averaged over 42°–53°N and 0°–15°E, with linear regression fits using the Ordinary Least Squares (OLS, blue) and Reduced Major Axis (RMA, red) methods, respectively. The OLS regression slopes are reported in Fig. 1 in the main article.

Source data

Extended Data Fig. 2 Trends in ozone precursor emissions.

a, b, Trends in anthropogenic emissions of carbon monoxide and non-methane volatile organic compounds (NMVOCs) in Europe (40–60N; 10W–25E) from the CMIP6 historical dataset used by the model. c, Observed trends in global average methane mixing ratios used by the model. d, Model estimated trends in biogenic isoprene emissions over Europe (40°–60°N;10°W–25°E).

Source data

Extended Data Fig. 3 Surface ozone trends.

Maps of the 1990–2015 trends in daily MDA8 ozone for the 95th and 50th percentiles in July and August from observations (top) and IAVDEPV simulations (bottom). Results are shown for EMEP sites with at least 20 years of data, with larger circles indicating sites with significant ozone trends (p < 0.05). The percentage of sites with significant trends are reported at the top-left corner of each graph.

Source data

Extended Data Fig. 4 Ozone pollution during the 2015 and 2018 heatwaves.

(Top) Maps of observed daily maximum temperature anomalies in June-August of 2015 and 2018 relative to the base period 19611990, with dots indicating area in drought (SPEI06 <−1). (Middle) The annual 4th highest MDA8 ozone concentrations from all available observations gridded at 0.5° resolution, with values above 70 ppb implying an exceedance of the health limit set by the U.S. Environmental Protection Agency. (Bottom) The annual 26th highest MDA8 ozone concentrations, with values above 60 ppb implying an exceedance of the health limit set by the European Union.

Extended Data Fig. 5 Evolution of drought events.

The Standardized Precipitation-Evapotranspiration Index (SPEI) integrated over the preceding 6 months, 2 months, and 1 month for August 2003, July 1994 and July 2006.

Extended Data Fig. 6 Land use.

a, Fraction of the four land use categories in each grid cell averaged over 20002015: Natural forests (lands undisturbed by human activities), secondary vegetation (lands harvested at least once, including managed forests and abandoned cropland and pasture), croplands, and pastures. b, Changes in 20002015 relative to the 1960s. The box denotes the area used for averaging in Extended Data Fig. 7.

Extended Data Fig. 7 Declining ozone removal by vegetation due to stomatal closure under soil drying as opposed to land use changes.

a, b, Evolution of land use over western Europe (5°W–25°E and 40°–55°N): total land areas and area-weighted leaf area indices for natural forests (dark green), secondary vegetation (green), croplands (orange), and pastures (blue). c, Evolution of June-August mean daytime ozone deposition velocities for the four land use types (area-weighted). d, Total (solid green lines) and stomatal (dashed green lines) ozone deposition velocities averaged over natural and secondary vegetation land areas. The vertical bars show the percentage of land areas in drought (SPEI06<−1; right axis).

Source data

Extended Data Fig. 8 Climate-driven trends in surface ozone over Europe.

Maps of the 19792014 and 19902014 trends in the 95th and 50th percentile MDA8 ozone concentrations for July (a) and August (b), simulated by the IAVDEPV_FIXEM experiment with anthropogenic emissions held constant at 1980 levels. Stippling denotes areas where the change is statistically significant at the 95% confidence level (p < 0.05).

Extended Data Fig. 9 Observed trends in hot extremes over Europe.

Maps of the 1979–2019 trends in the frequency of warm days (that is, those above the 90th percentile for the base period 1961–1990) in July (a) and August (b), respectively, obtained from the Global Land-Based Datasets for Monitoring Climate Extremes (Methods). Stippling denotes areas where the change is statistically significant (p < 0.05).

Extended Data Fig. 10 Drivers of decadal mean ozone trends in Europe.

Changes in decadal mean ozone levels during spring (March-May) and summer (June-August) from 19791989 to 20012010 as inferred from surface observations at Hohenpeissenberg (985 m altitude, MDA8 values), from alpine observations at Zugspitze (2962 m altitude, 24-hour mean), and from 1990–2000 to 2001–2010 at 52 EMEP sites over 40°N–55°N with continuous observations (MDA8 values). For observations, both changes in decadal mean (grey bars) and median (circles) values are shown, with the error bars indicating the range of the mean change at the 95% confidence level. Model results are shown for the BASE (total; red bars) and IAVDEPV_FIXEM (climate-driven trends; green bars) experiments and the contributions from changes in Asian anthropogenic emissions (purple bars), global methane concentrations (cyan bars), and wildfire emissions (yellow bars). For comparisons with free tropospheric observations at the Zugspitze, model results are sampled at 700 hPa.

Source data

Source data

Source Data Fig. 1

Statistical source data.

Source Data Fig. 2

Statistical source data.

Source Data Fig. 3

Statistical source data.

Source Data Fig. 4

Statistical source data.

Source Data Fig. 5

Statistical source data.

Source Data Extended Data Fig. 1

Statistical source data.

Source Data Extended Data Fig. 2

Statistical source data.

Source Data Extended Data Fig. 3

Statistical source data.

Source Data Extended Data Fig. 7

Statistical source data.

Source Data Extended Data Fig. 10

Statistical source data.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Lin, M., Horowitz, L.W., Xie, Y. et al. Vegetation feedbacks during drought exacerbate ozone air pollution extremes in Europe. Nat. Clim. Chang. 10, 444–451 (2020). https://doi.org/10.1038/s41558-020-0743-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41558-020-0743-y

This article is cited by

Search

Quick links

Nature Briefing Anthropocene

Sign up for the Nature Briefing: Anthropocene newsletter — what matters in anthropocene research, free to your inbox weekly.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing: Anthropocene