Climate Flooding Risk ‘Misjudged’
Climate change may carry a higher risk of flooding than was previously thought, the journal Nature reports.
Researchers say efforts to calculate flooding risk from climate change do not take into account the effect carbon dioxide (CO2) has on vegetation.
Higher atmospheric levels of this greenhouse gas reduce the ability of plants to suck water out of the ground and “breathe” out the excess.
Plants expel excess water through tiny pores, or stomata, in their leaves.
Their reduced ability to release water back into the atmosphere will result in the ground becoming saturated.
Areas with higher predicted rainfall have a greater risk of flooding. But this effect also reduces the severity of droughts.
The findings suggest computer models of future climate change may need to be revised in order to plan for coming decades.
Soil saturation
Plants perform two functions that are of key importance in climate change.
They absorb CO2 from the atmosphere and convert it to oxygen as a by-product of their energy generation process.
Plants also absorb water through their roots, and release it back into the atmosphere through their stomata.
CO2 enters plants through the stomata; water evaporates through the same holes.
The higher the level of atmospheric CO2, the more the pores tighten up or open for short periods.
As a result, less water passes through the plant and into the air in the form of evaporation. In turn, this means that more water stays on the land, eventually running off into rivers when the soil becomes saturated.
A team led by Dr Richard Betts from the Met Office has modelled how this will affect climate change predictions.
“It’s a double-edged sword,” said Dr Betts, “it means that increases in drought due to climate change could be less severe as plants lose less water.
“On the other hand, if the land is saturated more often, you might expect that intense rainfall events are more likely to cause flooding.”
© BBC MMVII
Root rot anyone? I don’t think our crops can evolve fast enough to keep up with climate change.
I live in Oregon where the current climate provides the habitat for fir trees. They are huge, with a very shallow wide pan root system. When the soil gets waterlogged and the wind blows (not too common here), they pop out of the ground and come crashing down.
Interesting times ahead. Anyone ready to wake up? Or are people waiting for a really good reason to do so?
Everyone is waiting for someone - some government, some corporation, some law, some savior. We have all been waiting far too long. Now the living Earth itself is seriously disrupted, and we are all still looking around, waiting…
When i was 12 years old, in 1971, i read a book called “The Closing Circle” by scientist Barry Commoner, who later ran for President. His book - more than 35 years ago - laid out (among other serious environmental truths) the basic facts about how humans pumping carbon into the atmosphere would change the climate. It’s actually not complicated at all, despite the massive smoke screens that have been spewed by industry and politicians and think-tanks for the past thirty-five years - carbon dioxide retains heat better than other gases that make up air. Duh.
It seemed so obvious, i have never driven a car. i have watched the entire time as we collectively live in denial, careening toward GLOBAL CATASTROPHE. Not only watched, i have also been a writer and an activist, but it has been horrific to watch.
i have never understood how so many of us keep living in denial. Like when DCBeltway was like, “But my job depends on fossil fuels! And my job is good! You can’t tell me to stop flying!” That is living in denial.
So, anyway, for what it’s worth, here we go people, please enjoy the ride. And no one can say they did not know. The truth about global warming has been obvious for decades, as we all kept pumping more carbon into the atmosphere, and we still are, and we are still waiting for someone to change a law, or invent a device, as if it actually were so damned important to not disrupt my life over THE FATE OF CIVILIZATION.
Anyone willing to take steps to disrupt your own precious life over this? Or do you prefer to keep waiting for Al Gore to save us?
Sorry if i sound a little bitter…
Methane from cows is also a problem. Perhaps Oprah was right about all those hamburgers. Why are the Feds going after the chicken pluckers and not the ranchers? Oh, the Feds ARE ranchers. Got any Gopher wood?
I read the paper in Nature by Betts et al., and I must say that as a forest hydrologist, I am skeptical that the mechanism invoked (increased stomatal closure) will have much impact on flood frequency and magnitude. The spatial and temporal scales (global 20-yr means of precip and runoff) that Betts used do not permit conclusions about flooding. And the increase in global mean runoff due the stomatal closure effect of doubling of CO2 is only 6% relative to preindustrial conditons. The authors do speculate that “With greater increases and smaller decreases in runoff due to physiological forcing, the risks of rain and river flooding may increase…because intense precipitation events would be more likely to occur over saturated ground”. But during heavy prolonged rainfall, the antecedent soil moisture is far less important than the rainfall intensity. Think of the recent floods in SE Minnesota; one station had 15.1 inches of rain in 24 hrs, after days of rain. The effect of warming of the oceans and atmosphere on rainfall depth-duration-frequency will far outweigh the effect of a slight decrease in transpiration due to increased stomatal closure.
However, take no comfort. The more scientific publications you read about climate change, the more alarmed you will become. A good rule of thumb is: the situation is worse than you think.
Question for you bloggers:
Which one of the Presidental candidates is the most “GREEN”? Which one “gets it”
I want to know, so I can get out the vote for him/her.
I live in Iowa, so my vote can make a difference whether a candidate gets heard or not.
I don’t want any crap about why Iowa should be the first to vote. I think it should be a rotating deal between the states, but, at least this year, Iowa is right there at the front.
There are a lot of very important issues, but global warming is the most important.
MRFOAD, try Kucinich. He gets it and has the courage to do the right thing. The rest of them are talking about incremental change which won’t make a dent in the problem. He is the only candidate who has no ties to the corporate welfare state. Edwards is a distant second, but his plans are too little, too late. Sweden has the best solution, carbon tax. And has taken dramatic strides reducing their carbon footprint. Good luck.
MRFOAD, here is the link to Dennis’ website on a sustainable future.
http://www.dennis4president.com/go/issues/a-sustainable-future/
Bob Coats: thanks for the hard data. I too doubt the significance of the effect cited by the author. The headline is the hook for this piece and there is reason to believe we aren’t prepared for the EFFECTS of flooding that may be the result of global climate change. If a pattern is emerging of more frequent heavy rainfalls - saturating storms of lasting duration - many areas of (historically)stable soil will find their communities washing away. That happened here in the upper Ohio River valley during Ivan and we haven’t recovered yet. Many roads are still closed - unrepaired - because all our money is in war don’t you know.
webwalk…
join us at http://www.freepublictransit.org
this is doable, when it reaches critical mass, people will love car-free living so much they will overpower the oil/auto/coal oligarchy.
CommonDreams didn’t like the syntax of the hyperlink I inserted, so here’s the full text:
The Depauperate World of 2049
And what an equitable, just and ecologically sustainable society will look like
The Earth, human society and those species with who we share creation are on a crash course with global ecological collapse characterized by horrific death and destruction. Human populations have exploded and in sum have become a disease consuming the ecological systems which provide for their habitat and being. Environmentalism such as it is remains mostly bureaucratic greenwashing, seeking to defend practices such as ancient forest logging and excessive personal air travel, which are the very activities that have led to our fatal situation in the first place and continue to threaten the Earth. This meander attempts to pull together seemingly discordant themes of recent essays into a coherent vision for your and the Earth’s future.
“Depauperate” — meaning lacking in numbers of variety of species, impoverished — is a particularly apt biological term which captures Gaia’s and humanity’s future prospects rather well given current trends. This reduction in biodiversity through excessive population and consumption is the core of the Earth crisis. The challenge of environmental communication and campaigning is to truthfully highlight the absolutely atrocious, dire, depauperate future with which we are faced; while simultaneously spawning personal actions and societal policies that are of sufficient magnitude to solve global ecological problems. This must be done without entirely bogging down in feelings of desperate helplessness; but not at the expense of not telling the truth, advocating insufficient responses, or justifying continued personal excessive consumption.
There is no road to a sustained, desirable human future that does not include enlightened self-sacrifice and voluntary simplicity as we learn to live well and sustainably in a post-modern age. The obstacles include vile talking heads such as Rush Limbaugh and Sean Hannity; that as evil incarnate stupidly and in an ill-informed manner defend a system careening towards planetary self-immolation. And in my opinion only slightly less damaging to long-term planetary prospects are Madonna, Al Gore and Leonardo DiCaprio — knowing there is an urgent crisis, using their formidable skills to communicate it to others, but showing unwillingness to lead by example and check their own opulent conspicuous consumption.
We have seen the future, we know the problem, and it is us. A messenger, carrying a message of crisis caused by their own doings, that is unwilling to make necessary changes in lifestyle, deserves metaphorically to be “shot”. The global ecological emergency cannot be solved by anything less dramatic than immediate efforts to first stabilize and then reduce human population, development of a consumption ethic informed by ecological constraints, and leadership by example — showing rather than telling others what must be done simply to survive.
Given current trends what can be expected
Much of the world lives in grinding poverty, with billions barely meeting basic needs on one or two dollars a day. This will increasingly become the norm of human existence. The over-developed world stands as a fortified compound within a sea of poverty and destroyed ecosystems of their own making. The next forty years will witness a siege and continued diminishment in areas living opulently, until the world descends into barbarity and eventual loss of complex life. Along the way, if we stay our present course, we will witness every variety of environmental, political and social calamity.
Resource scarcity and over-population will lead to an end to economic growth. This is good news in that nothing can grow exponentially forever, and the industrial growth machine is the engine of planetary destruction. However, resulting economic decay and widespread dramatic reductions in living standards in the excessive West will lead to calls for further resource over-exploitation and ecosystem destruction. The fate of the Earth will be sealed by desperate, ill-informed efforts to fuel unsustainable consumption patterns by those accustomed to the throw-away, consumptive lifestyle as the meaning of life.
The future will include fierce competition and military conflict as too many people seek to maintain long-standing unsustainable resource use. I believe we will first see broad-based societal collapse in China, which unthinkingly took upon itself the ill-conceived Western economic model based upon liquidation of natural capital. China has pursued capitalism so extravagantly that within a decade we should expect ecological collapse and militarism in pursuit of continued resource over-use. All weapons that exist including nuclear will be used. I believe we shall see political, economic and ecological collapse in China first, then the U.S. and finally Europe.
This collapse is due to a thousand causes. Climate change will lead to worsening extreme weather conditions. This will become evident particularly in the availability of water and reduced agricultural production. Seasonality will be lost, land made unproductive, water critically short of supply, and a comfort demanding public forced to fend for themselves. Starving thirsty mobs will loot, rape and pillage — ensuring that recovery in any real sense over large areas of even a simplified civilized lifestyle will be impossible. One would expect hundreds of million to die from emergent diseases exacerbated by ecosystem and global change. But this entirely predictable corrective course by Gaia will be too little too late to allow for the maintenance of complex life and civilization such as it is.
A small cadre of individuals aware of the global ecological emergency and cognizant of the need to reduce population and consumption will be undermined by stars and politicians telling us we can eat our Earth and have it too. The chimerical message that we can all live like rock and movie stars will undermine rigorous efforts to do what must be done to save the Earth. And thus the emerging global police state will have justification to destroy the radical environmental movement which was the Earth’s only last great hope.
Given free will and an enlightened sense of self interest things will be different
It need not be so. Humanity and the Earth have everything necessary to build an equitable, just and ecologically sustainable future for all forever. Greed and lack of humanity will be overcome as we each learn and commit to living ethically as one amongst billions of Earth consumers. Flawed; yet knowledgeable, real and truthful human leaders will emerge spreading a deep ecological message, and that are actually willing to demonstrate a lifestyle that is simple, rich, truthful and fulfilling; that could be universalized to meet basic human needs for all; still allow hard-workers to relatively thrive, and even provide for luxury in moderation. An adequate vision of the transformative personal and cultural journey necessary to get there will be embraced. Efficiency and elegance of design will become commonplace. Every musician will have a fine instrument, carpenters their tools; yet the days of multiple large cars, private aviation, and McMansions will be over.
There are many modern activities which as drivers of climate change and global ecological change in general are simply irredeemable. Global ecological sustainability will be achieved by ending continued deforestation and industrial diminishment of the Earth’s great ecosystem engines found in the last large, intact and contiguous forest wildlands. Coal and oil burning will cease at any scale. Industrial development of natural terrestrial and oceanic ecosystems will be halted, and these biological materials used as the blueprint and seed stocks for restoration of over half of the Earth’s surface as global ecological reserves. Strictly enforced population controls — one or at most two children per couple — will be fairly implemented.
There are other activities associated with the comforts of modern life (by some) that could continue, but must be done in moderation to not exceed the carrying capacity of an already frayed Earth that is in recovery. These include aviation, eating meat, and consumption of luxury consumer goods. Frugal flying to be with relatives, conduct business that cannot occur otherwise, infrequent excursions to experience and be part of another bioregion’s restoration all will be justified. Hopping on a plane, much less a private one, to fly off on a whim cannot. Thus a post-modern ecological life will mean less mobility, and living more richly where you find yourself.
Human populations will be called upon to live within the means of the resources provided by their local bioregion. There will be a broad-based return to the land, not living subsistence lifestyles necessarily, but all people will begin growing and raising more of their own food even as they earn their livelihoods by restoring ecosystems through permaculture and ecological restoration. Trade that does occur must be of a surplus that does not eat into the natural capital principal of the region.
Vegetarianism is by far the preferred diet for an over-populated planet under stress, yet eating meat is not unnatural. There exists a big difference between eating the natural flesh of animals raised using centuries old sustainable and humane animal husbandry practices; and recent factory farming methods. Just as with all non-essential consumption, meat consumption will be dramatically reduced and eliminated when possible.
Critical to global ecological sustainability will be personally learning to sustain ourselves. Personal hang-ups will be gotten over, the past faced up to, amends made and we will move forward together. The pervasive ills of modern society — including childhood sexual abuse, drug dependence, and alienation from our fellow humanity — are intimately entwined with, and are the logical consequences, of over-population, atomization of society, and the widening gap between those that have it all and those dying from want. Healing yourself is a vital, irreplaceable first step to joining with others to heal the Earth. Few humans are irredeemable, and all can benefit from being one with Gaia. Let the journey to full self-actualization and global ecological sustainability begin.
RE: misanthrope August 31st, 2007 12:05 am
Interesting Gaia pipe dream and even more interesting the future date, 2049, a year before the age of Aquarius traditionally begins (give or take). I’m not sure that with the effects of global climate change, depleted uranium usage, mercury, arsenic, aspartame, avian flu & other biological agents, poor quality & scarce water, and other undiscovered agents we have been poisoning ourselves with, whether anyone will still be around by then, or if the norm will be three headed children. I’ll be 101 so I guess it won’t matter much, but since I plan to live until 109 at least I’ll have a few years of heaven on Earth. Now…how do we cause an ecological paridigm shift that will get us there is the ‘elephant in the room’ question?
RE: whatfools August 30th, 2007 2:28 pm
When I was a geology major back in the late ’60’s & early ’70’s one of my geology professors asked a trick question. He queried, “What is the largest methane generation source in the world?” Of course, although he made us acutely aware of such items as peak oil, the future greenhouse effect due to increased CO2 generation, etc, he never considered or spoke of the enormous release of methane we will see from the uncovering of Arctic tundra (which could be the correct answer…now).
Although many in the class guessed cows we were incorrect. No, his claim was, are you ready for this? Termites!
It seems for every man, woman, and child on this planet there are about 1,800 POUNDS of termites, whose primary foodstuff is cellulosic materials (wooden stuff), and the byproduct of their digestive process is methane. I used to joke about the image of some lab tech running around with a glass container trying to capture & measure the volume of a termite fart, but now it is not really a laughing matter anymore, is it? HELL YES IT IS!!! We have to be serious about dealing with these environmental issues, but if we completely lose our sense of humor what is the point of living? Anyway, I just thought I’d pass that little bit of trivia along.
RE: kathyodat August 30th, 2007 12:48 pm
I know what you mean about the soggy ground and trees with shallow root systems coming down.A few years ago (3-4) Hurricane Isabel hit the east coast near where I live. Although I’m approximately 100 miles inland (Richmond VA) the preceding several days were very rainy. There are a lot of pines around, and of course they got devastated, but even huge oaks & others, that had been around for several hundred yeard, came crashing down. In all it was estimated that over a million trees in VA alone bit the dust, or mushy ground, or whatever. I’m not really looking forward to another such episode, but the realist in me imagines the next time will be even worse.
Yes, I agree Dennis K. is the best environmental option, and I wouldn’t even mind seeing he & Al Gore in some combination on the ticket. Even if they don’t make it cabinet positions heading the EPA & Interior Depts would be entirely appropriate.
webwalk and bill,
Thanks for the link. When I first moved to a the walking-and transit-friendly (and very affordable) neighborhood of Bloomfield of Pittsburgh, I found it positively liberatory.
Totally aside it’s untenable environmental impacts, it became clear that the car long ago ceased to be a convienience and more akin to a ball-and-chain - with enormous negative social impacts as well.
But, it is tough job - most people, particularly in the suburbs positively can’t imagine a community orgainzed any other way but around the car. And, in Pittsburgh’s latest thrust to “modernize” (i.e. neoliberalize) itself, it is making deep cuts in it’s public transit. We could be a Portland, OR, but it apears our insular city council’s preferrred model to emulate is Charlotte, NC or sone other god-awful “sunbelt” city.
“Only 6% relative to pre-industrial conditions” might be a significant amount of water. The world had a lot more unpaved-over surface to absorb water with in those times. When an inch of rain falls over a forest, the result is a lot different than when an inch of rain falls over the buildings, shopping centers, freeways, roads, and other hard scape that make up a city.
Modern levee systems protect one place by preventing what used to be a natural overflow of river channels, and just push all that water onto places downstream until something gives. And “give” it eventually will.