When It Rains, It Pours: Study Confirms Climate Change Will Keep Driving More Intense Precipitation

Posted on  

"When It Rains, It Pours: Study Confirms Climate Change Will Keep Driving More Intense Precipitation"

Climate change will bring more and more extreme precipitation events this century.

A new study from NOAA’s National Climatic Data Center confirms what climate scientists have long been saying about climate change’s effect on the hydrological cycle.

If you are not familiar with this term, you are certainly familiar with what it describes. As the sun warms the earth, water evaporates from oceans, lakes, and rivers, which then form clouds that produce rain and snow. More evaporation happens when the ocean and the air is warmer, which has been happening steadily for some time.

The NOAA study, published in Geophysical Research Letters, found that extreme precipitation events will become more intense this century as the globe continues to warm. Extra moisture expected from that warming will be the dominant factor fueling this increase in extreme precipitation, with a 20 to 30 percent more precipitation in the Northern Hemisphere by 2099.

The paper looked at three factors that go into the maximum precipitation value possible in any given location: moisture in the atmosphere, upward motion of air in the atmosphere, and horizontal winds. The team examined climate model data to understand how a continued course of high greenhouse gas emissions would influence the potential maximum precipitation. While greenhouse gas increases did not substantially change the maximum upward motion of the atmosphere or horizontal winds, the models did show a 20-30 percent increase in maximum moisture in the atmosphere, which led to a corresponding increase in the maximum precipitation value.

Percent maximum daily precipitation difference (2071-2100) - (1971-2000). (Photo credit: NOAA)

They looked at possible changes in winds that could offset increased water vapor, but found that those changes would be too small. We already know that specific events cannot be said to be directly caused by climate change, but as Kevin Trenberth puts it, “All weather events are affected by climate change because the environment in which they occur is warmer and moister than it used to be.” And we know that NOAA’s projections have already started to become the reality: a study in Nature found that several of the last decade’s extreme weather events would not have occurred without climate change.

The study’s authors hope that this will allow water managers, engineers, and infrastructure planners to better identify risks and mitigate potential disasters. National reports like this are valuable not only because funds for flood risk prevention studies are often attacked in Congress, but because climate impacts are often ignored, forcibly, at the state level. South Carolina buried an important report on climate impacts. North Carolina made it illegal to consider the latest climate science when preparing coastal regions for sea level rise.

Related Posts:

« »

23 Responses to When It Rains, It Pours: Study Confirms Climate Change Will Keep Driving More Intense Precipitation

  1. Leif says:

    About a year ago on CP I asked “How much water does 4% extra amount to?” The question is beyond my pay grade but another CP commentator did the math and came up with ~1.5 X the volume of Lake Superior. I have not seen conformation and would love to see some. Anyone?

    It is important to remember that once you get heavy rain someplace that water is not “gone” as it is quickly replaced with new evaporation. This is the NEW NORMAL!

    • Colorado Bob says:

      The same week :

      Some 100,000 households were destroyed by the floods, La Plata mayor Pablo Bruera said.

      Provincial officials said 40cm (16in) of rain fell on La Plata in the space of two hours late on Tuesday night.

      Earlier, the storm dumped 15cm of rainfall on the capital, Buenos Aires.

      “We’ve never seen anything like it,” said provincial governor Daniel Scioli.

      “People were taken by surprise, and some didn’t have time to escape this deadly trap.”

      http://www.bbc.co.uk/news/world-latin-america-22033533

    • Jay Alt says:

      copying my earlier reply –
      (#14) from 2.2.10 CP: President Obama Explains the science behind climate change and extreme weather

      @3. Leif asks an interesting question – how much is that extra 4% ?

      http://www.eoearth.org/article/Hydrologic_cycle
      . . . At any given time, the atmosphere contains about 13,000 km3 water,
      . . . annual water movement through the atmosphere that results in 111,000 km3 being precipitated upon land.
      Land percentage is nearly 30% and assume like rainfall everywhere -> ~ 370,000 km^3 annual precipitation over land+ocean. Take 4% to get ~14,800 km^3/ year extra water.
      . . . http://en.wikipedia.org/wiki/List_of_lakes_by_volume
      So, the annual extra pptn falling is nearly the volume of 1.5 Superiors or 2X that of Michigan+Huron.

      • Leif says:

        Thank You Jay. So the next logical question. Is that increase lineal, when we double that to 8% do we get 3 times Lake Superior? Does the holding capacity increase ~ 4% per degree increase?

        • Joan Savage says:

          “Given that atmospheric water-holding capacity is expected to increase roughly exponentially with temperature—and that atmospheric water content is increasing in accord with this theoretical expectation”

          – Seung-Ki Min, et al 2011.

          “Basic theory, observations and climate model results all show that the increase in water vapor is roughly 6 percent to 7.5 percent per degree Celsius warming of the lower atmosphere.”

          -Livermore Lab fact sheet 2007.

          The links for these are in another post that is in moderation at the moment.

    • Joan Savage says:

      Leif, I’d like to pin it down, too. I didn’t crack it with a single reference but found some interesting partial answers.
      It might be just as important to ask,
      * At what point in the recent past did the atmosphere increase reach 4% over baseline?
      and
      * What is the rate of increase?

      In 2011, an article in Nature, “Human contribution to more-intense precipitation extremes” confirmed increase in atmospheric moisture for two-thirds the land in the Northern Hemisphere. The abstract is worth a read.
      http://www.nature.com/nature/journal/v470/n7334/abs/nature09763.html

      In 2007 the Lawrence Livermore National Laboratory published a fact page that said, “The atmosphere’s water vapor content has increased by about 0.41 kilograms per square meter (kg/m²) per decade since 1988, and natural variability in climate just can’t explain this moisture change. The most plausible explanation is that it’s due to the human-caused increase in greenhouse gases.”

      https://www-pls.llnl.gov/?url=science_and_technology-earth_sciences-moisture

      We could work from the LLNL number using square meters of earth surface.
      Note: In a 1996 publication, Gleick estimated 3,094 cubic miles of water (12,900 cubic kilometers) in the atmosphere.
      http://ga.water.usgs.gov/edu/watercycleatmosphere.html
      I wouldn’t count on Gleick’s composite number published in 1996 to be a precise cut for eight years after the LLNL data set started.

  2. The more part is one aspect.

    More disturbing are the when and where. As the ice cap disappears, and the temperature gradient between the pole and the lower latitudes literally degrades, the jet stream will become more erratic and meandering.

    The persistent warm nighttime temps in Michigan in March 2012 as snow fell in Rome, and Hurricane Sandy taking an abrupt left at New Jersey, are mild harbingers of disruptions to come. Agriculture is in deep trouble.

  3. Henry says:

    I hope more rainfall will help with drought and dessertification!
    H.

    • Leif says:

      It does not necessarily happen where you need it Henry. Quite the contrary, evidence is mounting that the wets get wetter and dries get drier.

  4. Joan Savage says:

    Stating the obvious–

    We already have loss of soil fertility through rapid erosion and/or overlayment of agricultural fields with less-fertile silt and mud from floods.

    We already have disruptions of fresh water supply and sewer management due to more severe rainfalls.

    We already have the tragedies of loss of homes and life.

    Increased rainfall beyond what we already face will place agricultural fertility, reliable freshwater supply, and public sanitation and safety at great risk.

    Enough already.

  5. Rabid Doomsayer says:

    More drought and more flood, but much less normal. Our industrial agriculture, particularly grains, requires well behaved weather.

    Flood, drought, drought does not bode well for future grain production. Repeated failure of grains will lead to hungry people and in the US the hugry people will be armed.

    Armed hungy people, does not bode well for political stability. How long before the next American Revolution?

  6. zoom314 says:

    To think Teabagger Repubs wanted to get rid of(defund) NOAA, stupid idiots…

  7. norman clark says:

    Be good for growing rice..

  8. Bob h says:

    Measurement of the atmosphere’s water vapor content is so straightforward that climate change deniers have a hard time denying that it is real. Water vapor represents potential energy because energy was put into producing it from the oceans.

  9. ZoeyKay says:

    It would be nice if we could consolidate future flooding to the southern states. It would save the country a ton of money, since they don’t believe in funding disaster relief.

  10. Timothy laurent says:

    Zoeykay..dont screw us all here down south because of a bunch of inbred asswipes ideological idgits and tea party retards ya got a bunch of progressives that will get drowned out too