Rules of thumb for climate change turned upside down

September 14, 2014
Clouds over Australia are shown. Credit: NASA

With a new analysis of land regions, ETH climate researcher are challenging the general climate change paradigm that dry regions are getting drier and wet regions are getting wetter. In some regions they are encountering divergent trends.

Based on models and observations, have devised a simplified formula to describe one of the consequences of : regions already marked by droughts will continue to dry out in the future . Regions that already have a moist climate will experience additional rainfall. In short: dry gets drier; wet gets wetter (DDWW).

However, this formula is less universally valid than previously assumed. This was demonstrated by a team of ETH climate researchers led by Peter Greve, lead author of a study recently published in Nature Geoscience. Traditional analyses use metrics that can comprehensively describe climate characteristics above the ocean, but is problematic over land. While this fact was mentioned in said studies, scientific and public discourse has overlooked this aspect so far. In their new study, the ETH researchers in the group headed by Sonia Seneviratne's, professor for land-climate dynamics, take into account the specific climatic properties of land surfaces, where the amount of available water is limited when compared with the ocean.

In their analysis, the climate scientists made use of measured data compiled solely on land, such as rainfall, actual evaporation and potential evaporation. The data derived from various sources was combined by Greve and his co-authors – this allowed them to extract trends in terms of a region's humidity and dryness. Furthermore, the researchers compared data from between 1948 and 1968 and 1984 to 2004.

Half of the surface areas show divergence

The evaluation shows no obvious trend towards a drier or wetter climate across three-quarters of the land are. There are solid trends for the remaining quarter. However, only half of this surface area follows the DDWW principle, i.e. one-eighth of the total landmass, while the trends seem to contradict this rule over the other half.

Some regions which should have become wetter according to the simple DDWW formula have actually become drier in the past – this includes parts of the Amazon, Central America, tropical Africa and Asia. On the other hand, there are dry areas that have become wetter: parts of Patagonia, central Australia and the Midwestern United States.

Nevertheless, the 'wet gets wetter' rule is largely confirmed for the Eastern United States, Northern Australia and northern Eurasia. 'Dry gets drier' also corresponds to indications in the Sahel , the Arabian Peninsula and parts of Central Asia and Australia.

However, the DDWW principle does still applies to the oceans. "Our results emphasise how we should not overly rely on simplifying principles to asses past developments in dryness and humidity," Greve explains. This can be misleading, as it cannot do justice to the complexity of the underlying systems.

Explore further: Climate change will make some tropical regions wetter – then dry them out

More information: Greve P, Orlowsky B, Müller B, Sheffield J, Reichstein M, Seneviratne SI. Global assessment of trends in wetting and drying over land. Nature Geoscience, Advanced Online Publication 14th September 2014. DOI: 10.1038/ngeo2247

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Jack Wolf
3.2 / 5 (11) Sep 14, 2014
We are at war. But, I am brave. You are too. Whatever the cost, we shall defend our island planet, whatever the cost may be, I shall fight on the beaches, I shall fight on the landing grounds, I shall fight in the fields and in the streets, I shall fight in the hills; we shall never surrender to the fossil fuel foe. It is no use saying, 'We are doing our best.' You have got to succeed in doing what is necessary. This is our ultimate challenge, the stuff that epic history is made of. Don't stay home and watch it on the tellie. Be there and share. Be brave.
Peoples Climate March: NYC 9.21.14
Noumenon
1.8 / 5 (21) Sep 14, 2014
The alarmists have frightened the children.
antigoracle
1.5 / 5 (22) Sep 14, 2014
One more nail in the AGW Cult's coffin and their CO2 lies.
dev_dangol
1.2 / 5 (19) Sep 14, 2014
First prove gases cause global warming. Can you?

GH gas theory is ridiculous, imaginary, false, spurious and so on. Gases can't form green house. So green house effect due to gases is impossible. They are actually helping the earth to cool down by convection method of heat transmission. Gases have freely moving molecules, so you can't fix any fluid to make a structure. let us first have water for every body and every where! by developing water supply networks. Moisture content on land surface controls our climate. No dry part on the land surface of the earth! Nature will take care rest. We are expanding more and more dry land surface by urbanization, deforestation and deserts formation causing climate change and power crisis.
Man-made not gas-made. For solution to power crisis and climate change
visit my blog for details

devbahadurdongol.blogspot.com
mbee1
1.3 / 5 (15) Sep 15, 2014
the writer of this piece is finnally writing what has been known for years, the models are bogus and always have been. Since the climate has not changed per the IPCC fifth report in 16 years the climate is not even changing much less the rainfall patterns. The idea everything would stay the same and get more extreme was and is a boggyman to scare the taxpayers into making Al Gore and company much much much richer.-+-----------------
mbee1
1.5 / 5 (16) Sep 15, 2014
Jack just as a matter of idle curiosity, how much CO2 will you and your friends pump into the air to get to, be in , and go home from that march? You do know you are condemning our kids to a much warmer planet part of which will be due to your march. Save the planet, stay home.
cantdrive85
1.6 / 5 (14) Sep 15, 2014
we shall never surrender to the fossil fuel foe.


Well...except to ride the planes, trains, and automobiles to the march.

Rube!
antigoracle
1.3 / 5 (12) Sep 15, 2014
This is our ultimate challenge

NO!!
Your ultimate challenge is to grow a brain and use it to see what ignorant hypocrites you are.
Mike_Massen
4.3 / 5 (12) Sep 15, 2014
antigoracle the ordinary propagandist again
One more nail in the AGW Cult's coffin and their CO2 lies.
There is nothing in this article about CO2 & any reference to its irrefutable thermal properties. There is nothing in this article about thermal models either.This is about distribution on land regarding drier vs wetter regions, it is still under study.

dev_dangol lumbered with
First prove gases cause global warming. Can you?
Easy. Uni students in laboratories can do it any time they like, many have tried to prove it wrong and failed. In order to understand the mechanism you need to; Have a grounding in calculus, study infra red (IR). molecular vibrations & IR re-radiation. Its actually quite simple & provable, the maths does not lie its also. Unfortunately, no one has ever proven it wrong it is also consistent with the paradigm offered in this question.

"How can ADDING a gas with known thermal properties of re-radiation NOT increase heat flow resistivity ?"
Mike_Massen
4.4 / 5 (13) Sep 15, 2014
mbee1 muttered with obvious propaganda bia
the writer of this piece is finnally writing what has been known for years, the models are bogus and always have been. Since the climate has not changed per the IPCC fifth report in 16 years the climate is not even changing much less the rainfall patterns.
This article says nothing about the thermal models that do show high correlation. What is surprising is just how much the oceans absorb heat - its approx 1000x that of atmosphere !

What a great deal of people never discovered & which the bulk of deniers cannot appreciate is that melting ice has approx 150x the heat sink capacity of ice at below zero degrees.

ie.Melting ice at zero degC when changing to water at zero degC absorbs massive amount of heat this reduces local temperatures offering a buffer effect. The concern is that once the buffers are gone we face that same amount of heat raising ocean temperature more.

Please consider we are burning ~230,000 Liters of Petrol per sec.
AkiBola
1.8 / 5 (10) Sep 15, 2014
I thought this was all Settled Science, the ice caps were going to be gone by now and the earth would be warming?

Still confused by the IPCC report that showed temperatures rising before CO2 levels rose, concluding that warming is caused by rising CO2 levels. I must have skipped the "effect and cause" lesson at school.
Mike_Massen
4 / 5 (8) Sep 15, 2014
AkiBola muttered
I thought this was all Settled Science, the ice caps were going to be gone by now and the earth would be warming?
The arctic ice cap has lost lots of mass & it appears its re-icing cycle is constrained. The antarctic being in the southern hemisphere has a somewhat different dynamic. What were you thinking, did it come from dumb media hype or a proper peer reviewed climate science article ?

AkiBola went on
Still confused by the IPCC report that showed temperatures rising before CO2 levels rose, concluding that warming is caused by rising CO2 levels. I must have skipped the "effect and cause" lesson at school.
There is evidence of temperature rises some millenia ago that resulted in higher CO2 but, as far as I know there are NO IPCC reports which show temp rise THEN CO2 rise !

I'm sorry you suffer from (your own source of) confusion(s)... Might I earnestly advise:-

Please be smart & link directly to the report instead of claiming such obtuse report exist ?
Noumenon
1.5 / 5 (8) Sep 15, 2014
I thought this was all Settled Science, the ice caps were going to be gone by now and the earth would be warming?


They were just joking around. According to this report, scientists now say AGW causes more antarctic ice because of the winds. If i'm to be an alarmist this shows that global warming will cause the oceans to freeze (j/k).

This does not mean that AGW isn't real, ....just that climate science does not really have a handle on it to the precision that is fraudulently claimed,... and that the AGW Alarmists should be ignored.
Mike_Massen
4 / 5 (8) Sep 15, 2014
Noumenon makes arbitrary claims & twists with
They were just joking around. According to http://www.abc.ne...5742668, scientists now say AGW causes more antarctic ice because of the winds. If i'm to be an alarmist this shows that global warming will cause the oceans to freeze (j/k).
You missed out the word 'extent' !

Why Noumenon are you lying by purposely leaving out an important word 'extent' ?

Why Noumenon don;t you know 'extent' is Not Equal to Mass ?

Did u do maths or ANY linguistics when in school ?

Pray tell Noumenon WHY are you being so obviously purposely obtuse & so everyone notices ?
RWT
1.5 / 5 (8) Sep 15, 2014
I can't wait to ride my unicorn to the NY Climate March. My unicorn will be farting glitter and lollypops the entire way, but no CO2 bygolly. For one day, on 9-24-14, the average IQ of NYC will drop below 70 as thousands of us unicorn riding pilgrims will descend on the city to prove to the world that the mental midget climate cult can find NYC.
antigoracle
1.5 / 5 (8) Sep 15, 2014
There is nothing..blah...blah. There is nothing ...blah...blah
--mikemassen
There is nothing in the space between your ears, so there is nothing anyone can do but leave you to believe in the lies of your AGW Cult.
Steve 200mph Cruiz
4.6 / 5 (9) Sep 15, 2014
There are 7,000,000,000 people on this planet, with every one of them starting fires with just about every one burning coal, cutting down rainforests for livestock, and every one processing food.
The boundary between the atmosphere and outer space is called the Karman Line, which is about 62 miles above the seas level. Considering the fact it's only an hour drive to outer space, with 7 Billion people contained in that marginal volume, how can you guys honestly say we have no impact? Just one dude can stink up his living room in a day.
Eddy Courant
1.7 / 5 (6) Sep 15, 2014
It's so cold... I turned on my furnace last night. A full month earlier than other years.
Egleton
4.2 / 5 (5) Sep 15, 2014
Lett us not be naieve. The Carbon Bros. pieces are pre-wtitten and have no bearing on the article. The word "climate" triggers off an automatic dump of total crap.
Noumenon
2 / 5 (4) Sep 15, 2014
Noumenon makes arbitrary claims & twists with
They were just joking around. According to http://www.abc.ne...5742668, scientists now say AGW causes more antarctic ice because of the winds. If i'm to be an alarmist this shows that global warming will cause the oceans to freeze (j/k).
You missed out the word 'extent' !

Why Noumenon are you lying by purposely leaving out an important word 'extent' ?


Yes, extent, thank you for that correction. What does the following mean to you (?)......

"There are also as yet no published data on [antartic] sea ice volume—a much better measure of whether sea ice is increasing or decreasing."
antigoracle
1.5 / 5 (8) Sep 15, 2014
Shortest, coolest summer this year. I expect a lot of people will be wishing for global warming this winter.
Vietvet
3.7 / 5 (9) Sep 15, 2014
Shortest, coolest summer this year. I expect a lot of people will be wishing for global warming this winter.


Maybe where you are but S. Calif is experiencing the warmest year since records have been kept.
megmaltese
2.2 / 5 (5) Sep 15, 2014
Take any system, increase its temperature.
Cold and warm areas will experiment more variation in temperature, because flows will have longer life and lenght.
Take Earth, increase its temperature: more locations will receive different streams, more cold or more hot.
This statement that Earth wet locations become wetter and dry become drier was stupid since the very beginning.
Mike_Massen
4.2 / 5 (10) Sep 16, 2014
antigoracle cant reply with Science so he attacks the person
There is nothing in the space between your ears, so there is nothing anyone can do but leave you to believe in the lies of your AGW Cult.
I know its difficult for you but, it is IS smarter to put the effort in to understanding the Science. There are community colleges & likely open lectures where physicists can answer questions thereafter sometimes in private so you won't feel embarrassed in front of others...

The Science of:-
- CO2 as a GHG & re-radiation properties is settled.
- Earth's thermal balance is known & GHG shift that equilibrium
- Water properties ie. Massive capacity if melting ice to reduce temperatures MORE than ice.
etc
ie. Can't be a cult, be smarter antigoracle & get up to speed on the Science foundations.

antigoracle admitted he cant tell climate from weather
Shortest, coolest summer this year. I expect a lot of people will be wishing for global warming this winter
Education is so important !
Mike_Massen
3.7 / 5 (6) Sep 16, 2014
Noumenon offered this reply
Yes, extent, thank you for that correction. What does the following mean to you (?)..According to http://www.abc.ne...5742668, on [antartic] sea ice volume—a much better measure of whether sea ice is increasing or decreasing."
Increased extent will hopefully increase reflection. I'm in the Southern Hemisphere & noticed number of humid/hot days in Perth Australia going up. Perhaps the increase in ice extent along with ice mass melting will reduce temperatures in my area in summer only a few months away.

It is no fun having days of 45 deg C with minimal respite in between (sigh) of 'only' 35 deg C !

I notice many focus on ice but don't delineate volume vs extent vs mass, especially MR166 who, having been informed of this disparity STILL refuses to include the dichotomy in his short posts, just like ryggesogn2 as if they are related. Why are both similar in their approach, they spout politics often !
MR166
2.3 / 5 (3) Sep 20, 2014
Mike you and I both know that satellite measurements of sea ice extent began in 1979. This also happens to be a time when the earth was exiting one of it's many cold decades. Thus, sea ice extent and of course volume was at a high point. At this point in time governments and climate science were predicting a new ice age. Then it got a little warmer and predictions changed to ice free poles. Now the ice extent seems to be returning but it is meaningless to you because the volume is not there. Well you know what, it was thick enough to last through and Arctic summer and still have a significant extent remaining.
MR166
1 / 5 (1) Sep 20, 2014
BTW that should read "an Arctic summer". I am one person who needs a 1/2 hour edit period instead of 3 min..
MR166
1 / 5 (1) Sep 20, 2014
Here is a little interesting quote from the NYT.

"Worse, trees emit reactive volatile gases that contribute to air pollution and are hazardous to human health. These emissions are crucial to trees — to protect themselves from environmental stresses like sweltering heat and bug infestations. In summer, the eastern United States is the world's major hot spot for volatile organic compounds (V.O.C.s) from trees.
As these compounds mix with fossil-fuel pollution from cars and industry, an even more harmful cocktail of airborne toxic chemicals is created............"

http://www.nytime...tml?_r=1

Yup I live in a world gone crazy.

Vietvet
5 / 5 (3) Sep 20, 2014
BTW that should read "an Arctic summer". I am one person who needs a 1/2 hour edit period instead of 3 min..


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