Tag Archives: predictions

World Population Set to Hit 9.1 Billion in 2050

World Population Set to Hit 9.1 Billion in 2050: Scientific American.

At current growth rates, forecasters expect to see a total of 9.1 billion humans on Earth by 2050, although small shifts in the birth rate might add or subtract one billion people. The rise could be slowed without taking any direct measures to control population. The most effective way to reduce fertility rates is to educate women: worldwide, each additional year of female education lowers the average birth rate further. Greater education correlates with more abstinence, birth control and female employment, each of which lowers birth rates.

Source: United Nations Population Division

Bleak Prospects for Avoiding Dangerous Global Warming

Bleak Prospects for Avoiding Dangerous Global Warming – ScienceNOW.

The bad news just got worse: A new study finds that reining in greenhouse gas emissions in time to avert serious changes to Earth’s climate will be at best extremely difficult. Current goals for reducing emissions fall far short of what would be needed to keep warming below dangerous levels, the study suggests. To succeed, we would most likely have to reverse the rise in emissions immediately and follow through with steep reductions through the century. Starting later would be far more expensive and require unproven technology.

Published online today in Nature Climate Change, the new study merges model estimates of how much greenhouse gas society might put into the atmosphere by the end of the century with calculations of how climate might respond to those human emissions. Climate scientist Joeri Rogelj of ETH Zurich and his colleagues combed the published literature for model simulations that keep global warming below 2°C at the lowest cost. They found 193 examples. Modelers running such optimal-cost simulations tried to include every factor that might influence the amount of greenhouse gases society will produce —including the rate of technological progress in burning fuels efficiently, the amount of fossil fuels available, and the development of renewable fuels. The researchers then fed the full range of emissions from the scenarios into a simple climate model to estimate the odds of avoiding a dangerous warming.

The results suggest challenging times ahead for decision makers hoping to curb the greenhouse. Strategies that are both plausible and likely to succeed call for emissions to peak this decade and start dropping right away. They should be well into decline by 2020 and far less than half of current emissions by 2050. Only three of the 193 scenarios examined would be very likely to keep the warming below the danger level, and all of those require heavy use of energy systems that actually remove greenhouse gases from the atmosphere. That would require, for example, both creating biofuels and storing the carbon dioxide from their combustion in the ground.

“The alarming thing is very few scenarios give the kind of future we want,” says climate scientist Neil Edwards of The Open University in Milton Keynes, U.K. Both he and Rogelj emphasize the uncertainties inherent in the modeling, especially on the social and technological side, but the message seems clear to Edwards: “What we need is at the cutting edge. We need to be as innovative as we can be in every way.” And even then, success is far from guaranteed.

Can we predict earthquakes?

BBC News – Can we predict when and where quakes will strike?.

l'Aquila earthquake Seismologists try to manage the risk of building damage and loss of life

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This week, six seismologists go on trial for the manslaughter of 309 people, who died as a result of the 2009 earthquake in l’Aquila, Italy.

The prosecution holds that the scientists should have advised the population of l’Aquila of the impending earthquake risk.

But is it possible to pinpoint the time and location of an earthquake with enough accuracy to guide an effective evacuation?

There are continuing calls for seismologists to predict where and when a large earthquake will occur, to allow complete evacuation of threatened areas.

What causes an earthquake?

An earthquake is caused when rocks in the Earth’s crust fracture suddenly, releasing energy in the form of shaking and rolling, radiating out from the epicentre.

The rocks are put under stress mostly by friction during the slow, 1-10 cm per year shuffling of tectonic plates.

The release of this friction can happen at any time, either through small frequent fractures, or rarer breaks that release a lot more energy, causing larger earthquakes.

It is these large earthquakes that have devastating consequences when they strike in heavily populated areas.

Attempts to limit the destruction of buildings and the loss of life mostly focus on preventative measures and well-communicated emergency plans.

Predicting an earthquake with this level of precision is extremely difficult, because of the variation in geology and other factors that are unique to each location.

Attempts have been made, however, to look for signals that indicate a large earthquake is about to happen, with variable success.

Historically, animals have been thought to be able to sense impending earthquakes.

Noticeably erratic behaviour of pets, and mass movement of wild animals like rats, snakes and toads have been observed prior to several large earthquakes in the past.

Following the l’Aquila quake, researchers published a study in the Journal of Zoology documenting the unusual movement of toads away from their breeding colony.

But scientists have been unable to use this anecdotal evidence to predict events.

The behaviour of animals is affected by too many factors, including hunger, territory and weather, and so their erratic movements can only be attributed to earthquakes in hindsight.

Precursor events

When a large amount of stress is built up in the Earth’s crust, it will mostly be released in a single large earthquake, but some smaller-scale cracking in the build-up to the break will result in precursor earthquakes.

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There is no scientific basis for making a prediction”

Richard Walker University of Oxford

These small quakes precede around half of all large earthquakes, and can continue for days to months before the big break.

Some scientists have even gone so far as to try to predict the location of the large earthquake by mapping the small tremors.

The “Mogi Doughnut Hypothesis” suggests that a circular pattern of small precursor quakes will precede a large earthquake emanating from the centre of that circle.

While half of the large earthquakes have precursor tremors, only around 5% of small earthquakes are associated with a large quake.

So even if small tremors are felt, this cannot be a reliable prediction that a large, devastating earthquake will follow.

“There is no scientific basis for making a prediction”, said Dr Richard Walker of the University of Oxford.

In several cases, increased levels of radon gas have been observed in association with rock cracking that causes earthquakes.

Leaning building Small ground movements sometimes precede a large quake

Radon is a natural and relatively harmless gas in the Earth’s crust that is released to dissolve into groundwater when the rock breaks.

Similarly, when rock cracks, it can create new spaces in the crust, into which groundwater can flow.

Measurements of groundwater levels around earthquake-prone areas see sudden changes in the level of the water table as a result of this invisible cracking.

Unfortunately for earthquake prediction, both the radon emissions and water level changes can occur before, during, or after an earthquake, or not at all, depending on the particular stresses a rock is put under.

Advance warning systems

The minute changes in the movement, tilt, and the water, gas and chemical content of the ground associated with earthquake activity can be monitored on a long term scale.

Measuring devices have been integrated into early warning systems that can trigger an alarm when a certain amount of activity is recorded.

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Prediction will only become possible with a detailed knowledge of the earthquake process. Even then, it may still be impossible”

Dr Dan Faulkner University of Liverpool

Such early warning systems have been installed in Japan, Mexico and Taiwan, where the population density and high earthquake risk pose a huge threat to people’s lives.

But because of the nature of all of these precursor reactions, the systems may only be able to provide up to 30 seconds’ advance warning.

“In the history of earthquake study, only one prediction has been successful”, explains Dr Walker.

The magnitude 7.3 earthquake in 1975 in Haicheng, North China was predicted one day before it struck, allowing authorities to order evacuation of the city, saving many lives.

But the pattern of seismic activity that this prediction was based on has not resulted in a large earthquake since, and just a year later in 1976 a completely unanticipated magnitude 7.8 earthquake struck nearby Tangshan causing the death of over a quarter of a million people.

The “prediction” of the Haicheng quake was therefore just a lucky unrepeatable coincidence.

A major problem in the prediction of earthquake events that will require evacuation is the threat of issuing false alarms.

Scientists could warn of a large earthquake every time a potential precursor event is observed, however this would result in huge numbers of false alarms which put a strain on public resources and might ultimately reduce the public’s trust in scientists.

“Earthquakes are complex natural processes with thousands of interacting factors, which makes accurate prediction of them virtually impossible,” said Dr Walker.

Seismologists agree that the best way to limit the damage and loss of life resulting from a large earthquake is to predict and manage the longer-term risks in an earthquake-prone area. These include the likelihood of building collapsing and implementing emergency plans.

“Detailed scientific research has told us that each earthquake displays almost unique characteristics, preceded by foreshocks or small tremors, whereas others occur without warning. There simply are no rules to utilise in order to predict earthquakes,” said Dr Dan Faulkner, senior lecturer in rock mechanics at the University of Liverpool.

“Earthquake prediction will only become possible with a detailed knowledge of the earthquake process. Even then, it may still be impossible.”

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Weather Service pleads to be spared from cuts

Weather Service urges to be spared from spending cuts | Reuters.

MIAMI | Thu Aug 4, 2011 5:53pm EDT

(Reuters) – Nature has not stinted in unleashing deadly weather on the United States this year and leaders should recognize the need for good forecasting services when they wield the cost-cutting knife, the director of the National Weather Service said on Thursday.

Jack Hayes used the opportunity of the National Oceanic and Atmospheric Administration’s updated 2011 Atlantic hurricane forecast to stress “what taxpayers are getting in return for their investment in the National Weather Service,” which is part of NOAA.

A hard-fought deficit-cutting deal passed by Congress and signed into law by President Barack Obama this week foresees $2.1 trillion in overall budget savings over 10 years, with painful cuts expected across the government.

“Here in Washington, D.C., our nation’s leaders are making extremely tough decisions about federal spending, including what government services to fund and which to trim in efforts to reduce the nation’s deficit,” Hayes said on a conference call before the hurricane forecast update.

Calling this situation a “pressing issue,” Hayes said 2011 has been a record year so far for extreme weather.

“Many recent events have shattered long standing records for tornadoes, floods, blizzards, wildfires and now we’re experiencing, throughout much of the nation, heat waves,” he said.

Tornadoes raking across the United States this year killed more than 540 people, and these and other extreme weather events have caused $32 billion in economic losses so far, making it a costly year, Hayes said.

“And we’re only halfway through the year with the bulk of the hurricane season still ahead,” he added.

Predicting the Atlantic-Caribbean region was heading for a busier-than-average 2011 hurricane season, NOAA experts raised their activity outlook, forecasting 14 to 19 tropical storms, with seven to 10 of those growing into hurricanes.

The National Weather Service chief said the service’s outlooks and forecasts provided key weather and climate information to industries from aviation to farming, tourism and fishing, to states and local municipalities, power companies and emergency managers.

“Accurate and timely weather services are important in people’s daily lives but, even more important, they are a critical part of rebuilding the nation’s economic security and reducing tragic loss of precious lives,” Hayes said.

(Editing by Vicki Allen)

Are we entering an age of major earthquakes?

Are we entering an age of major earthquakes? – CSMonitor.com.

A study of more than a century of global seismic records has prompted some scientists to say that major earthquakes have tended to occur in clusters. Others disagree.

Japan Ground Self-Defense Force members search in the rain for victims’ belongings in a devastated area in Minami Soma, northeastern Japan, Tuesday.

Hiro Komae/AP

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By Charles Q. Choi, OurAmazingPlanet Contributor / April 20, 2011

A number of devastating quakes have struck across the globe in recent years — from Japan to Chile to Haiti — sparking fears that our planet is due to experience even more catastrophic temblors in the near future.

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Three research teams have now combed through 110 years’ worth of global seismic records to see if we might be caught in a global trend of giant earthquakes.

Some say we are; others disagree.

Megaquake clusters

One pair of researchers found clusters of what they called “megaquakes,” earthquakes of magnitude 9.0 or greater.

One cluster involved three such quakes between 1952 and 1964, including the magnitude 9.5 Chile quake of 1960, the largest earthquake ever recorded on Earth. Another, larger, cluster of magnitude 8.6 and higher temblors happened between 1950 to 1965, said Charles Bufe and David Perkins, seismologists with the U.S. Geological Survey in Golden, Colo. They speculate that the magnitude 8.4 Peru quake in 2001 could mark the beginning of a new global sequence of major quakes that we are currently experiencing.

“This isn’t doomsday — I don’t think large earthquakes will occur over a long period of time — but we’re saying there seems to be a cluster right now with a higher than normal probability for large quakes,” Bufe told OurAmazingPlanet. “I don’t know how long this cluster might last — if we don’t get another large earthquake in maybe the next 10 or 12 years, I would say we’re probably out of the cluster.”

Bufe suggested that by sending seismic waves traveling around and around the planet’s surface, very large earthquakes might weaken fault zones that are already very close to failure. “I think there’s a more than 50 percent chance we’ll see another magnitude 9 quake sometime in the next decade or so,” he said.

Just chance?

On the other hand, this apparent recent spike in large quakes could just reflect random fluctuations in global patterns of seismic activity. A statistical study from U.S. Geological Survey researcher Andrew Michael at Menlo Park, Calif., suggests this seeming cluster pattern disappeared once local aftershocks of the large earthquakes are taken into account.

“The most important lesson is that random doesn’t mean uniformly distributed in time — instead, random processes create apparent clustering and it is important to carefully consider whether apparent clusters, or times of less activity, go beyond what is expected from a simple random process,” Michael told OurAmazingPlanet. “So far, my results show that the apparent clustering is consistent with a random process.”

If the apparent clustering of these quakes is a matter of chance, then seismologists can’t say whether or not another huge temblor is likely to erupt anytime soon.

“The recent spate of great earthquakes can be explained as a random fluctuation without predictive power for the future,” Michael said. He added that global predictions of earthquakes and the damage they inflict should use the longest possible historical record for an area “rather than focusing on the recent past.”

Long-term record

Seismologist Richard Aster at the New Mexico Institute of Mining and Technology and his colleagues looked at historical catalogs of earthquakes along with more recent findings to create a long-term record of the cumulative size of earthquakes around the world.

They suggest there were relatively low rates of big earthquakes during the periods 1907 to 1950 and 1967 to 2004. However, they found the rate of large earthquakes increased substantially during the period 1950 to 1967 and appears to be on the rise again since 2004, since the devastating magnitude 9.1 to 9.3 earthquake that struck Indonesia and generated a massive tsunami late that year.

Still, this finding “is not statistically differentiable from randomness,” Aster told OurAmazingPlanet.

Progress into understanding whether there are ages of major quakes or not may be slow “because we just don’t get that many great earthquakes to produce a better sampling of this natural process,” Aster said.

“We only get a few magnitude 9-plus earthquakes per century, for example — fortunately for earthquake risks around the world, these events are rare,” Aster said. “There are only 14 earthquakes in the past 111 years greater than magnitude 8.5.”

Michael agreed. “The main limitation is that we don’t have enough data,” he said. “We can’t say that clustering doesn’t exist. We can only say that the data doesn’t let us reject the hypothesis that the data is random. If there was more data, then the results could change — but that will take decades to occur.”

The scientists detailed their findings on April 14 at the Seismological Society of America meeting in Memphis, Tenn.