"Subsiding land is a bigger immediate problem for the world's coastal cities than sea level rise."
I see that some of the formatting for the Gondolas of Wall Street post is messed up and that I forgot to add a link to the USA TODAY report, Rising sea levels torment Norfolk, Va. and coastal U.S. I'll fix the formatting when I can make the time. Here I want to clarify that the "Be Here Now" approach I favor to dealing with climate change, and which I think the ten-part 2013 USA TODAY series (Weathering the Change) I mentioned in Gondolas also favors, doesn't mean rejecting out of hand the best guesses of scientists about the drivers of climate change.
A reader who responded to the Gondolas post stated flatly that CO2 emissions aren't a driver of global warming and pointed me to where I could learn about the real drivers. (See the comment section at the post for his full comments.) It's just this kind of flat statement, found on both sides of the climate change debate, which puts my back up.
But I wonder how many would care all that much about the debate if it wasn't for the fact that scientists aren't just making pronouncements, governments are taking action based on the pronouncements.
This is bringing every mad inventor on the planet out of the woodwork.
The debate about whether global warming was caused by human activity picked up steam in the year 2000. That was when NASA put up satellites that began beaming back to Earth huge amounts of data that scientists and mathematicians have been trying to fit into a coherent picture about Earth's climate. The most objective among these people are frank in saying that interpreting the data is more art than science.
But in 2013 the USA TODAY editorial board -- USA TODAY being a middle of the road newspaper -- finally took a firm stand. The Board accepted the current majority opinion among climate scientists, which is that large amounts of man-made CO2 emissions are connected with global warming. even though the emissions might not be the only driver of the phenomenon.
Of course the majority opinion could be wrong. But the newspaper's series on climate change takes the practical stand that this is where we are now. And yet given some of the counterproductive attempts to deal with global warming that government has already backed; e.g., ethanol and carbon swaps, intelligent behavior going forward means not stampeding ourselves into the kind of situation that allowed NSA to turn our fears about terrorist attacks into a nightmare about surveillance.
We risk going down the same road with our attempts to stop global warming. One article in the USA TODAY climate series outlines various technological fixes being proposed to halt global warming. Some of the solutions sound wonderfully ingenious; some are nothing short of horrifying. Horror would be a big price to pay for trying to solve a problem that might not even be correctly identified at this time by science.
So I think the wise course, at this point, is the Be Here Now one. An example of this approach: We aren't absolutely certain about what's causing the sea level to rise. Yet it is absolutely certain that rising seas are only one half the problem for many large coastal cities. The other half is that the cities, the land on which they rest, is sinking.
How much are the cities sinking, how fast are they sinking, why are they sinking? -- we need to find that out 'yesterday,' on a case by case basis. This is because there are very sure technological solutions for the sinkage problem, the man-made aspect of the problem. But if the sinkage isn't addressed, then when you combine sinkage with even a small rise in sea level, the big U.S. coastal cities, especially on the Atlantic coast, are staring down the barrel of disaster with every major hurricane.
This isn't even talking about what the major West Coast cities could face if they're sinking, and if an earthquake eruption sends a major tsunami their way.
I add that the sinkage problem is one climate change-related topic that USA TODAY's series didn't address, perhaps because it's not a climate change issue even though it intersects with it. And the research team that prepared the series in 2013 might not have known about the issue. It wasn't until the latter part of last year that the scope of the problem got much publicity -- although I recall that some months after Superstorm Sandy wreaked havoc on the New Jersey coast, John Batchelor interviewed a reporter about the sinkage problem on the New Jersey coast. And as far back as 2007, London's sinkage problem had made the news, although not in the U.S..
To sum it up, the Be Here Now approach is to cover our bets. Do what we can now to address long-standing problems connected with coastal flooding that are a threat to lives and property, no matter what's causing a rise in sea levels.
Same approach can be applied to drought. The silvopasturing method of cattle raising, which I featured in an earlier post, conserves tremendous amounts of water. That method can be implemented even more cheaply than was discussed in the article I featured, if cultivating valuable timber isn't part of the pasturing.
Can this method, long in use in the American Southeast, be transferred to the Southwest? I think the idea is worth consideration, and there are plenty other ways to conserve water.
One Pundita reader commented that farmers in New Mexico could relocate to places in the USA such as Ohio, where water is cheap and plentiful. That might be an attractive solution for some. However, many of the farmers have roots in the New Mexico-Arizona region that go back many centuries.
Yet if they want to stay, it will take more than tenacity. They will have to forego tradition and learn to take advantage of every method now known for conserving water. The megadrought they're living through might have no connection with human activity; it could be cyclic and if it's part of a classic megadrought cycle, it could last for decades more.
If you read the article by Ari LeVaux that I featured, you were hit with the stunning news that as of 2012, at least, farmers in drought-stricken regions of New Mexico were still using the flood method of irrigating their crops. This water-wasting method includes a canal system inherited from the Spaniards, who got it from the Moors. Try to imagine how many gallons of water evaporate off those canals in the blazing heat and bone-dry air!
Ari mentioned that one of the farmers had decided it was time to convert to the drip tape method of irrigation. Ya think?
In short, there's plenty of low-hanging fruit without restoring to solutions that include "blasting sulfate aerosols into the stratosphere to reflect sunlight away from Earth." I am NOT making that up; see the USA TODAY article on technological fixes I linked to above.
I will leave you with the BBC's 29 April 2014 article on sinkage, or 'subsidence.' See the Beeb's website for source links in the report and an eye-popping graphic:
Megacities contend with sinking land
By Jonathan Amos, Science Correspondent
BBC News, Vienna
Subsiding land is a bigger immediate problem for the world's coastal cities than sea level rise, say scientists.
In some parts of the globe, the ground is going down 10 times faster than the water is rising, with the causes very often being driven by human activity.
Decades of ground water extraction saw Tokyo descend two metres before the practice was stopped.
Speaking at the European Geosciences Union General Assembly, researchers said other cities must follow suit.
Gilles Erkens from the Deltares Research Institute, in Utrecht, in the Netherlands, said parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other coastal urban settlements would sink below sea level unless action was taken.
His group's assessment of those cities found them to be in various stages of dealing with their problems, but also identified best practice that could be shared.
"Land subsidence and sea level rise are both happening, and they are both contributing to the same problem - larger and longer floods, and bigger inundation depth of floods," Dr Erkens told BBC News.
"The most rigorous solution and the best one is to stop pumping groundwater for drinking water, but then of course you need a new source of drinking water for these cities. But Tokyo did that and subsidence more or less stopped, and in Venice, too, they have done that."
The famous City of Water in north-east Italy experienced major subsidence in the last century due to the constant extraction of water from below ground.
When that was halted, subsequent studies in the 2000s suggested the major decline had been arrested.
Pietro Teatini's research indicates that significant instances of descent were now restricted to particular locations, and practices: "When some people restore their buildings, for example, they load them, and they can go down significantly by up to 5mm in a year." How far they descended would depend on the type and compaction of soils underneath those buildings, the University of Padova researcher added.
Like all cities, Venice has to deal with natural subsidence as well.
Large-scale geological processes are pushing the ground on which the city sits down and under Italy's Apennine Mountains. This of itself probably accounts for a subsidence of about 1mm each year. But on the whole, human-driven change has a greater magnitude than natural subsidence.
Scientists now have a very powerful tool to assess these issues. It is called Interferometric Synthetic Aperture Radar. By overlaying repeat satellite images of a specific location, it is possible to discern millimetric deformation of the ground.
Archives of this imagery extend back into the 1990s, allowing long time-series of change to be assessed.
The European Space Agency has just launched the Sentinel-1a radar satellite, which is expected to be a boon to this type of study.
[END REPORT}
********
No comments:
Post a Comment