Skip to main content

Thank you for visiting 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.

Climate-change study raises spectre of advancing Mediterranean desert

If the 2-degree warming threshold of the Paris agreement is exceeded, Mediterranean ecosystems will change beyond anything seen over the past 10,000 years.

Seville is set to get hotter and drier without major cuts to greenhouse-gas emissions.  Credit: Cristina Quicler/AFP/Getty

Seville and Lisbon have thrived for more than a thousand years in a temperate climate. But if global warming continues at the current pace, these cities will be in the middle of a desert by the end of the century, climate modellers report on 27 October in Science1.

Maintaining the region’s historic ecosystem ranges would require limiting warming to just 1.5 ºC, by making substantial cuts to the world’s greenhouse-gas emissions, the analysis concludes. Otherwise, the vegetation and ecosystems of the Mediterranean basin will shift as temperatures rise. Increasing desertification in southern Europe is just one of the changes that would result.

“Everything is moving in parallel. Shrubby vegetation will move into the deciduous forests, while the forests move to higher elevation in the mountains,” says Joel Guiot, a palaeoclimatologist at the European Centre for Geoscience Research and Education in Aix-en-Provence, France, and lead author of the study.

Guiot’s analysis combines a climate model with a vegetation model that predicts how plants on land will respond to changes in temperature, rainfall and the concentration of greenhouse gases in the atmosphere. He and his co-author, Wolfgang Cramer, scientific director of the Mediterranean Institute for Biodiversity and Ecology in Aix-en-Provence, looked at a range of outcomes based on different scenarios for the world’s future emissions. They include limiting warming to 2 ºC and 1.5 ºC above pre-industrial levels — the range set by the Paris climate pact ratified earlier this month.

Policy guide

“I like that they’re doing this comparison across different warming scenarios in line with the Paris agreement, to start to gauge the sensitivity to them,” says Benjamin Cook, a climate scientist at the NASA Goddard Institute for Space Studies in New York City.The study confirms the vulnerability of many ecosystems, and could guide policymakers’ efforts to help natural systems adapt to climate change, says Patrick Gonzalez, principal climate-change scientist at the US National Park Service based at the University of California, Berkeley2. “This study shows how essential it is for nations to meet their Paris commitments.”The situation in southern Europe is similar to the US southwest, Gonzalez points out: temperature increases drive droughts3. More carbon dioxide in the atmosphere means rising temperatures, less precipitation and then more drying that leads to desertification.The model used in the new study also reconstructs the history of an ecosystem’s vegetation. “Essentially, vegetation hasn’t changed much over the past 10,000 years,” says Filippo Giorgi, head of the Earth System Physics Section of the International Centre for Theoretical Physics in Trieste, Italy. “It’s interesting that they put potential future changes in that context.”Both the climate and vegetation models have significant uncertainties, however, and the models can account only for natural vegetation, rather than managed vegetation such as forests and crops. The study ignores the fact that humans continually affect ecosystems through land-use change, urbanization and soil degradation.“If we had the possibility of including these human impacts, it would be even worse than what we simulated,” Guiot says.


  1. Guiot, J. & Cramer, W. Science 354, 465–468 (2016).

    ADS  CAS  Article  Google Scholar 

  2. Gonzalez, P. et al. Global Ecol. Biogeogr. 19, 755–768 (2010).

    Article  Google Scholar 

  3. Cook, B. I., Ault, T. R. & Smerdon, J. E. Sci. Adv. 1, e1400082 (2015).

    ADS  Article  Google Scholar 

Download references


Related links

Related links

Related links in Nature Research

Paris climate deal: what comes next 2016-Apr-22

Future US megadroughts set to be the worst in 1,000 years 2015-Feb-12

Climate zones will shift faster as world warms 2013-Apr-22

Related external links

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Skibba, R. Climate-change study raises spectre of advancing Mediterranean desert. Nature (2016).

Download citation

  • Published:

  • DOI:

Further reading


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

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