NOAA Bombshell: Human-Caused Climate Change Already a Major Factor in More Frequent Mediterranean Droughts

NOAA reports that global warming is harming humans right now in a dramatic way:

Wintertime droughts are increasingly common in the Mediterranean region, and human-caused climate change is partly responsible, according to a new analysis by NOAA scientists and colleagues at the Cooperative Institute for Research in Environmental Sciences (CIRES). In the last 20 years, 10 of the driest 12 winters have taken place in the lands surrounding the Mediterranean Sea.

The magnitude and frequency of the drying that has occurred is too great to be explained by natural variability alone,” said Martin Hoerling, Ph.D. of NOAA’s Earth System Research Laboratory in Boulder, Colo., lead author of a paper published online in the Journal of Climate this month. “This is not encouraging news for a region that already experiences water stress, because it implies natural variability alone is unlikely to return the region’s climate to normal.”

The Mediterranean region accumulates most of its precipitation during the winter….

Reds and oranges highlight lands around the Mediterranean that experienced significantly drier winters during 1971-2010 than the comparison period of 1902-2010.  [Click to enlarge.]

The above is from a news release from the National Oceanic and Atmospheric Administration, “NOAA study: Human-caused climate change a major factor in more frequent Mediterranean droughts.”

It’s a bombshell for three reasons.  First, this NOAA team has not always found a human cause for extreme weather events, as Climate Progress discussed here.  Second, the study found that global warming is already driving drought in a key region of the world:  Climate change is harming a great many people now.  Third, the analysis provides important confirmation of climate predictions that human-caused emissions would lead to drying:  “The team also found agreement between the observed increase in winter droughts and in the projections of climate models that include known increases in greenhouse gases.”

This comes on the heel of the USGS study, that, despite its flaws still found, “The decrease of floods in the southwestern region is consistent with other research findings that this region has been getting drier and experienced less precipitation as a likely result of climate change.”

And these studies amplify the piece I had in the journal Nature this week that argued drying and Dust-Bowlification driven by climate change — and the impact on food insecurity — are probably the gravest threats the human race faces in the coming decades.

The fact that the NOAA analysis confirmed the climate models predictions of drying is especially worrisome because the climate models project a very dry future for large parts of the planet’s currently habited and arable land in the coming decades:


drought map 2 2030-2039

The National Center for Atmospheric Research figure [click to enlarge] charts the Palmer Drought Severity Index [PDSI] where “a reading of -4 or below is considered extreme drought.”  The PDSI in the Great Plains during the Dust Bowl spiked very briefly to -6, but otherwise rarely exceeded -3 for the decade (see here).

The 2010 NCAR study, which Climate Progress reported on here, notes “By the end of the century, many populated areas, including parts of the United States, could face readings in the range of -8 to -10, and much of the Mediterranean could fall to -15 to -20. Such readings would be almost unprecedented.”

Indeed, the new NOAA study should be especially sobering to those in the Mediterranean since they clearly face some of the most extreme drying in the entire world:

The Mediterranean has long been identified as a “hot spot” for substantial impact from climate change in the latter decades of this century because of water scarcity in the region, a rapidly increasing population, and climate modeling that projects increased risk of drought.

“The question has been whether this projected drying has already begun to occur in winter, the most important season for water resources,” Hoerling said. “The answer is yes.”

Here is the trend so far, from NOAA [click to enlarge]:

Winter precipitation trends in the Mediterranean region for the period 1902 – 2010.

NOAA further reports:

The Mediterranean region accumulates most of its precipitation during the winter, and Hoerling’s team uncovered a pattern of increasing wintertime dryness that stretched from Gibraltar to the Middle East. Scientists used observations and climate models to investigate several possible culprits, including natural variability, a cyclical climate pattern called the North Atlantic Oscillation (NAO), and climate change caused by greenhouse gases released into the atmosphere during fossil fuel use and other human activities.

Climate change from greenhouse gases explained roughly half the increased dryness of 1902-2010, the team found. This means that other processes, none specifically identified in the new investigation, also have contributed to increasing drought frequency in the region.

The team also found agreement between the observed increase in winter droughts and in the projections of climate models that include known increases in greenhouse gases. Both observations and model simulations show a sudden shift to drier conditions in the Mediterranean beginning in the 1970s. The analysis began with the year 1902, the first year of a recorded rainfall dataset.

In this analysis, sea surface temperature patterns emerged as the primary reason for the relationship between climate change and Mediterranean drought. In recent decades, greenhouse-induced climate change has caused somewhat greater warming of the tropical oceans compared to other ocean regions. That pattern acts to drive drought-conducive weather patterns around the Mediterranean. The timing of ocean temperature changes coincides closely with the timing of increased droughts, the scientists found….

Climate is a global phenomenon with global impacts on food prices and water security, and NOAA researchers are engaged in understanding changes in climate across many regions of the world. In the Mediterranean, winter drought has emerged as a new normal that could threaten food security. Lessons learned from studying climate in that region may also be relevant for the U.S. West Coast, which has a similar climate to the Mediterranean region of Europe and North Africa.

Dust-Bowlification is coming.  The only question now is whether we are going to act quickly to reduce emissions and avoid the very worst of the consequences.  As I’ll discussed in a future post, the kind of drying that is project is not something that you can adapt to in any meaningful sense of the word.

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21 Responses to NOAA Bombshell: Human-Caused Climate Change Already a Major Factor in More Frequent Mediterranean Droughts

  1. Peter Mizla says:

    In time the desert subtropical high will shift northward from the Sahara. In essence the Sahara will ‘jump the Mediterranean Sea’ into Spain, France, Italy, Greece, Croatia—

    The time line for this is as early as 2040. But is beginning now. The Alps will become mostly free of snow, and temperatures in Spain, Italy, Greece in the summer will routinely approach 115 degrees F.

    London by centuries end will have a climate similar to present day Casablanca. Madness.

  2. Mike Roddy says:

    “Climate change” is a little vague as a causative factor. I’d like to see more details.

    For example, what about deforestation, which is both an emission source and a feedback? In the US, we’ve learned that forests hold moisture in the soil and in overhead clouds. Kill the forest, and expect reduced precipitation.

    In Europe, Portugal, one of the hardest hit areas on the map, has experienced major forest fires and tree death in the last decade. It would be interesting to learn if the same phenomenom is operative in the other drought stressed Mediterranean countries.

  3. Mulga Mumblebrain says:

    Synergies will kill us, known and the nasty surprises.

  4. Robert In New Orleans says:

    Future heat and drought will make this years Arab Spring turn into a Arab Autumn of unimaginable suffering, civil disorder and chaos. We haven’t seen anything yet.

  5. Mimikatz says:

    Unfortunately there have also been severe rains and flooding in Italy. The beautiful Cinque Terre got 20 inches in just a few hours Wednesday and has had very severe mudslides that have devastated Monterosso and Vernazza. For those living there or who have visited there it is a real disaster and a tragedy.

  6. DR.A.Jagadeesh says:

    Yes. It is alarming. People and Governments should act fast.

    Dr.A.Jagadeesh Nellore(AP),India

  7. prokaryotes says:

    Key Message:

    “The timing of ocean temperature changes coincides closely with the timing of increased droughts, the scientists found.”

    Tweaked Message:
    “Climate is a weather affecting phenomenon with global impacts on food and water security, thus impacting populations across many regions of the world.”

  8. prokaryotes says:

    Further it should be pointed out, that “Many Regions of the World”, in particular the corn belt around the equator, are especially vulnerable. Affecting almost every single human, by creating direct or indirect effects in form of scarce resources, weather stressors (extremes) and could make parts of the world uninhabitable, due to resource limitations, high temperature (heat bulb temperature barrier) or sea level rise. And it doesn’t stops there, because of psychosocial impacts…

    Three classes of psychological impacts

    Direct (e.g., acute or traumatic effects of extreme weather events and a changed environment)
    Indirect (e.g., threats to emotional well-being based on observation of impacts and concern or uncertainty about future risks)
    Psychosocial (e.g., chronic social and community effects of heat, drought, migrations, and climate-related conflicts, and postdisaster adjustment).

  9. prokaryotes says:

    “The Mediterranean region accumulates most of its precipitation during the winter….”

    We can see where this is going… too much, too fast and at the wrong spots:

    Italy flood rescuers reach worst hit areas – videoItalian rescue workers reach towns and villages in Liguria that had been cut off by torrential rain and flash floods in which nine people died

  10. Lionel A says:

    Meanwhile for their efforts at wrecking the planet top execs also revel in much increased remuneration at the same time as the incomes of most are squeezed with many put below the poverty line Directors’ pay rose 50% in past year, says IDS report

  11. Joe Romm says:

    As I wrote in my Nature piece, Dust-Bowlifying regions increasingly get their precipitation in deluges, which isn’t much help.

  12. John McCormick says:

    Mike, we know the tropical zone is expanding north and south of the equator. And, that is causing an expansion of the Hadley cell dynamic that transfers moisture farther north and south. My limited understanding of that very complex shift of atmosphere but it is what I have read.

  13. Richard L says:

    The graph of winter precipitation trends could use more explanation. Is the negative winter precipitation due to evaporation exceeding rainfall for the season? If so, the amount seems quite extraordinary for the past 30-years.

  14. Colorado Bob says:

    GENEVA – Heavy rain is expected on the east coast of southern Thailand until the end of the week, the UN weather agency said Friday.

    “The moderate northeast monsoon prevails over southern Thailand and the Gulf of Thailand throughout the period,” said the World Meteorological Organisation.

    “Abundant rainfall is likely over the southern Thailand east coast. Especially in 28 to 30 October, isolated heavy to very heavy rain is expected in Chumphon southward,” it added.

    “Windwave in the Gulf of Thailand is about two metres high during the period,” it said.

    The country would also face “above average rainfall” over the next three months, added the WMO.

  15. Paul Magnus says:

    The map shows where all the large recent fires in the region have been occurring….

  16. Paul Magnus says:

    Hell and High Water!

  17. Paul Magnus says:

    People are feeling more uneasy now. One senses that the current rash of extreme events are not going to stop now and are even going to get worse. Which they are. Eaarth!

    We are definitely in some sort of amplified chaotic cycle link with the el nino/la nina etc cycles etc…. There is going to be no real respite for communities. The Great Contraction/Disruption is upon us.

    I have had a number of people (all of whom have been ignoring the GW issue) now start mention Armageddon is round the corner. They brush over the GW part, acknowledging it briefly and move on to saying what will be, will be…. its Gods will etc etc…

    May be its time to start praying also…

  18. Bill Walker says:

    Correct, of course, but it makes a story on Mediterranean drought a tough sell in the media or among “skeptics” right now.

  19. Joan Savage says:

    The popular press has not drawn a connection between population movement and climate change in North Africa and the Middle East. Like the stories on migration from Central America to the US, the Africa-Europe migrations are usually treated in the press as workers seeking opportunity, not mentioning much about fleeing from environmental and economic difficulty.

    There seems to also be an extraordinary level of migration to some countries in MENA (Middle East and North Africa).
    In 2000 Jordan’s population was 38.5% migrant stock, UAE 68.2% migrant stock!! (Baldwin-Edwards, 2005).

    Martin Baldwin-Edwards, 2005. Migration in the Middle East and Mediterranean. (There’s an indirect link to the pdf).

  20. Doc Snow says:

    Those folks aren’t buying, period. They won’t take a real look at what’s “on offer.”

    Hopefully, there are enough sane people around that we can actually begin to take action on carbon emissions before we hit 2 C warming. (Not *commitment* to 2 C, mind you, the warming itself!)

  21. Brian Dodge says:

    The zero line on the graph is the average winter precipitation for the entire period – probably near 200 mm. A year that shows -60 mm on the graph would have received only 140 mm of rain, instead of the expected 200 mm.