Tag Archives: climate change

Why Roman concrete still stands strong while modern version decays?

 

Scientists have cracked the secret to Roman water-based structures’ strength – and findings could help today’s builders

Scientist Marie Jackson has said Swansea lagoon’s seawall should be built using Roman concrete. Photograph: Tidal Lagoon Power/PA

Their structures are still standing more than 1,500 years after the last centurion snuffed it: now the Romans’ secret of durable marine concrete has finally been cracked.

The Roman recipe – a mix of volcanic ash, lime (calcium oxide), seawater and lumps of volcanic rock – held together piers, breakwaters and harbours. Moreover, in contrast to modern materials, the ancient water-based structures became stronger over time.

Scientists say this is the result of seawater reacting with the volcanic material in the cement and creating new minerals that reinforced the concrete.

“They spent a tremendous amount of work [on developing] this – they were very, very intelligent people,” said Marie Jackson, a geologist at the University of Utah and co-author of a study into Roman structures.

As the authors note, the Romans were aware of the virtues of their concrete, with Pliny the Elder waxing lyrical in his Natural History that it is “impregnable to the waves and every day stronger”.

Now, they say, they’ve worked out why. Writing in the journal American Mineralogist, Jackson and colleagues describe how they analysed concrete cores from Roman piers, breakwaters and harbours.

Previous work had revealed lime particles within the cores that surprisingly contained the mineral aluminous tobermorite – a rare substance that is hard to make.

The mineral, said Jackson, formed early in the history of the concrete, as the lime, seawater and volcanic ash of the mortar reacted together in a way that generated heat.

But now Jackson and the team have made another discovery. “I went back to the concrete and found abundant tobermorite growing through the fabric of the concrete, often in association with phillipsite [another mineral],” she said.

She said this revealed another process that was also at play. Over time, seawater that seeped through the concrete dissolved the volcanic crystals and glasses, with aluminous tobermorite and phillipsite crystallising in their place.

These minerals, say the authors, helped to reinforce the concrete, preventing cracks from growing, with structures becoming stronger over time as the minerals grew.

By contrast, modern concrete, based on Portland cement, is not supposed to change after it hardens – meaning any reactions with the material cause damage.

Jackson said: “I think [the research] opens up a completely new perspective for how concrete can be made – that what we consider corrosion processes can actually produce extremely beneficial mineral cement and lead to continued resilience, in fact, enhanced perhaps resilience over time.”

The findings offer clues for a concrete recipe that does not rely on the high temperatures and carbon dioxide production of modern cement, but also providing a blueprint for a durable construction material for use in marine environments. Jackson has previously argued Roman concrete should be used to build the seawall for the Swansea lagoon.

“There’s many applications but further work is needed to create those mixes. We’ve started but there is a lot of fine-tuning that needs to happen,” said Jackson. “The challenge is to develop methods that use common volcanic products – and that is actually what we are doing right now.”

Source:

https://www.theguardian.com/science/2017/jul/04/why-roman-concrete-still-stands-strong-while-modern-version-decays

Scientists say Miami could cease to exist in our children’s lifetime

Scientists speaking with New York magazine say Miami will disappear underwater within the century if sea-level rise persists.Shutterstock

Miami, a city of 430,000 people, could disappear within the century if the worst climate-change predictions come true.

New York magazine’s David Wallace-Wells spoke with dozens of climatologists and researchers in related fields for an investigation on the outcomes of climate change if aggressive preventative action isn’t taken. The results were not pretty.

“Most people talk as if Miami and Bangladesh still have a chance of surviving; most of the scientists I spoke with assume we’ll lose them within the century, even if we stop burning fossil fuel in the next decade,” Wallace-Wells said.

Located at the mouth of the Miami River on the lower east coast of Florida, Miami’s elevation on average is about 6 feet above sea level, according to CityData.com and NASA. South Florida as a whole anticipates a 2-foot increase in the sea level by 2060.

Within the century, a combination of polar melting, carbon emissions, and ice-sheet collapses could cause chronic flooding to wipe out Miami — and as many as 670 coastal communities, including Cambridge, Massachusetts; Oakland, California; St. Petersburg, Florida; and four of the five boroughs of New York City, according to National Geographic.

In January, a report from the National Oceanic and Atmospheric Agencyhinted at the possibility of an “extreme” sea-level-rise scenario that would support these predictions.

The research group Climate Central took the projections laid out in NOAA’s report and created a plug-in for Google Earth that shows how catastrophic the damage would be if the flooding happened today. You can install it (directions here) and see anywhere in the US.

Here’s what Miami may look like in the year 2100.

In the year 2100, you might need a rowboat to pass through it.

Google Earth/Climate Central

Climate Central’s plug-in for Google Earth shows a sea-level rise of 10 to 12 feet, which would cause the Atlantic Ocean to wash over Miami and the Miami River to overflow.

Google Earth/Climate Central

Everyone who lives in Miami would need to evacuate long before.

Google Earth/Climate Central

Google Earth/Climate Central

In Miami-Dade County, 1.6 million square feet of office space and 1.8 million square feet of retail space was under construction in the second quarter of 2016, the BBC reported.

Google Earth/Climate Central

Google Earth/Climate Central

Source: BBC

Those high-rises could have a different kind of ocean view by the end of the century.

Google Earth/Climate Central

Marlins Park may have a retractable roof, but that won’t save it from sea-level rise.

Google Earth/Climate Central

The Miami Marlins will require a name change.

Google Earth/Climate Central

The University of Miami, located south of downtown Miami in Coral Gables, hosts more than 16,000 students from around the world.

Google Earth/Climate Central

What Harvey Revealed About Climate Change in the South

© Photo by: Joe Raedle/Getty Images

To some, climate change is a vague idea, a hazy future. In parts of the South, it’s become a devastating reality.

“When you drive down the street there’s piles and piles of furniture, clothing, shoes, sound systems, just about anything you find inside a home,” Hilton Kelley, an environmental activist and former actor, says of Port Arthur, Texas, in Harvey’s aftermath. “It really looks like a war zone in many of our neighborhoods.”

For the residents of Port Arthur and nearby Houston, Hurricane Harvey was just the latest battle in the region’s ongoing conflict with an increasingly volatile Mother Nature.

 

 

“Katrina, we should’ve learned from that. If we didn’t learn from that we should’ve learned from Rita. If we didn’t learn from Rita, we should’ve learned from Ike. If we didn’t learn from Ike, we should’ve learned from Gustav,” says Kelley of the area’s stormy history. “How many hurricanes do you have to go through in 15 years to realize that this is the new norm?”

Port Arthur, like the South as a whole, is both uniquely located to feel climate change’s effects and uniquely vulnerable to its dangers, experts say. From Florida and the Gulf Coast to Kentucky and Southern Appalachia, the rising temperatures and more frequent extreme weather that come with climate change threatens to disrupt local economies and endanger working class communities.

“The southern U.S. is basically ground zero for climate change,” says Dr. Robert Bullard, a professor at Texas Southern University and the so-called “father of environmental justice.”

There’s the South’s geography, for one. Surrounded on one side by rising seas and susceptible to the heat waves and droughts of the lower latitudes, it’s suffered more billion-dollar weather and climate disasters than any other U.S. region going back to 1980. Texas alone has seen 94 of such events in that time frame, nearly 25 more than any other state.

“In Texas you get everything. You get ice storms and blizzards and tornadoes and flash flooding and haboobs and of course hurricanes,” says Katharine Hayhoe, a professor at Texas Tech University who contributed to the 2014 National Climate Assessment.

But geographic hazards are only part of what makes the South particularly at risk to climate change, Hayhoe says. There’s also the sheer number of people affected, and how vulnerable they are.

Despite the hazards, states like Texas have taken few steps to reduce risk. Although Texas leads the U.S. in terms of dollars paid for flood claims, it ranks among the worst in flood-control spending and doesn’t require its communities to enroll in FEMA’s National Flood Insurance Program. Suburban sprawl has led to new houses and developments being built on flood plains, and complicated emergency response. And migration to Texas and the South generally have only increased the region’s exposure, particularly for those pushed to the low-lying and less desirable areas.

“These weather and climate extremes broaden the gaps between haves and have-nots. If you have insurance versus if you don’t, if you can evacuate or you can’t,” Hayhoe says. “There’s a socioeconomic component to individual vulnerability.”

That vulnerability is a major reason why the South is set to be America’s biggest loser in the coming battles with a changing climate. An studypublished this summer in the journal Science, which used innovative methods to estimate climate change’s economic costs by region, predicted that climate change would hit the South the hardest: desecrating crop yields, increasing mortality rates, and exacerbating income inequality in what is already the country’s poorest region.

Harbingers of those dire predictions can already be seen in this year’s hurricane season.

Port Arthur, a low-lying, low-income, predominantly African-American community on the coast, proved more vulnerable than either Houston or south Florida.

“Other communities are thinking about rebuilding and reconstruction and shoring up infrastructure and making sure plans are being put in place to build a more resilient community,” Bullard says.

“Folks in Port Arthur, they’re just trying to get away from the pollution and the mold and the bad housing conditions to get to somewhere that’s high and dry.”

Communities such as Port Arthur stand to lose the most as extreme weather and rising seas threaten, Bullard says.

“Disasters actually create and amplify those health inequalities and other inequalities,” Bullard says.

“Those vulnerable, marginalized, low-income, people of color communities are the ones that will feel the negative impacts worst, first, and longest.”

The South’s politics, past and present, only add to the problem, Bullard says.

“Because of the way that the southern region developed and the way that the racial and ethnic segregation footprint was translated into policy, you’ll find a disproportionate share of poor people and people of color in the most vulnerable hotspots,” he says.

“The South has a legacy of slavery, Jim Crow segregation, and resistance to civil rights, and an disproportionate share of climate deniers who are in power in terms of governors and decision-makers.”

A few places are bucking the regional trend by preparing for what tomorrow’s climate may bring.

Two Southern coastal cities in Hurricane Irma’s path, Miami and Charleston, South Carolina, have taken steps to address rising sea levels. Miami is raising its streets and installing water pumps, and Charleston has spent or set aside at least $238 million on drainage projects aimed at reducing flooding.

In Charleston, sea levels have risen about a foot over the last century, due in part to sinking ground, says Doug Marcy, a coastal hazards specialist at the National Oceanic and Atmospheric Administration. The city also experiences frequent tidal floods.

“Just tides alone are starting to get into the stormwater system and fill them up, then when we get rain events they can’t drain,” Marcy says. “So you’ll have a sunny day but water will be in the streets and they have to close the streets and put up barricades.”

Both the floods and sea level rise will get worse: by 2040, the sea level could rise another 1.5 feet, and the tidal floods, which happened around twice a year as recently as the 1970s, could occur 180 days a year, according to projections.

To combat the rising waters, the city is building 10- and 12-foot-wide tunnels beneath the city as well as new pumping stations and other drainage improvement projects in the coming years. Though Charleston’s mayor John Tecklenburg has voiced his support for the Paris climate change agreement, South Carolina Gov. Henry McMaster and many of its lawmakers oppose it, and some city officials don’t directly frame their efforts in terms of climate change.

“To me it doesn’t matter what the cause is. What matters is the tide is rising and that’s having an impact on our people,” says Mark Wilbert, Charleston’s director of emergency management and resilience.

“Citywide there are people who know that this is happening because they see it happening to themselves and their neighbors and they understand what needs to be done.”

Farther south, the choices are more stark, the future more foreboding.

“We must look at a new way of building for those people who choose to stay here,” says Kelley, the activist and Port Arthur native. “If we want Port Arthur to survive, if we want Beamont to survive, we must look at a new way of existing on the gulf.”

Copyright 2017 U.S. News & World Report

Source: https://www.msn.com/en-us/weather/topstories/what-harvey-revealed-about-climate-change-in-the-south/ar-AAsmmuM?li=BBnb7Kz

Ex-climate change skeptic: Humans cause global warming

People Seem to forget how important this is, that is why I want to remind them, this is a article from 07/29/2012.

When the best scientists, including some of the few skeptics among them, study the data–and study it carefully and thoroughly–they too recognize the truth. And that was certainly true in the case of Cal-Berkeley physics Professor Richard Muller when asked to chair the Berkeley Earth Surface Temperature (BEST) project, set up for global warming skeptics. Now he too is among the unqualified believers. The evidence is strong and persuasive. And neither wishing it were not true, nor political spin, nor self-interested business denials, can change the truth of it at all. It’s what the data and analysis tell us. nbcnews.com reports:

Global warming not only is real, but “humans are almost entirely the cause,” a self-described former climate change skeptic has declared. “Call me a converted skeptic,” Richard A. Muller, University of California, Berkeley physics professor said in an opinion piece posted online Saturday in The New York Times.
Muller in October released results from the Berkeley Earth Surface Temperature (BEST) project, set up for global warming skeptics, that showed that since the mid-1950s, global average temperatures over land have risen by 0.9 degrees Celsius (1.6 degrees Fahrenheit).
In his new statement, Muller said, “Last year, following an intensive research effort involving a dozen scientists, I concluded that global warming was real and that the prior estimates of the rate of warming were correct. I’m now going a step further: Humans are almost entirely the cause.”

—“Ex-climate change skeptic: Humans cause global warming,” NBC News(7.29.2012)

For a useful review of the scientific opinion on global warming and the role of humans in it–including all the major scientific bodies that have affirmed it–see this article on Wikipedia, and others cited by it: “Scientific opinion on climate change.”

The Earth Is Warming Faster Now Than It Has in 11,000 Years

I am not sure if I should be mad or glad that some scientists decided to proof other skeptics that we are not simply living in a climate cycle and everything is repeating itself, as in the “ice age”. But I do know that further ignoring the truth will not get us anywhere, and as I have vision with http://www.plasmacor.com , so should others.

global warming projected

The global temperature anomaly projected into the future shows we’re in for trouble, a lot more than we have now.

2013: By Phil Plait

Global warming is real.

Let’s get that out of the way right at the start. Climatologist Michael Mann’s bombshell study from years back created the “hockey stick” graph, showing that in the past century, the Earth’s overall temperature spiked, like a case of planetary flu. This study was immediately attacked by climate change deniers, who continue to flail away at it today. It has withstood these attacks, and is no longer seriously doubted by scientists who actually study the climate.

And now, a new study shows that this spike in temperatures is unprecedented going back over one hundred centuries. They looked at global temperature anomalies—deviations from an average or standard temperature—for 73 sites distributed across the planet, using fossils in sediments as a proxy for temperature. The chemical and isotopic composition of the fossils yields a fairly accurate measure of the environment temperature at the time the animal or plant making up the fossil lived.

What they found is simply stunning: The rate at which the globe is warming right now is far, far faster than it ever has going back as far as they could measure, up to 11,300 years ago. In fact, over the past 5000 years, the Earth actually cooled by about 1.3°F…until the last 100 years, when our temperature spiked upwards by about the same amount.

Mind you, this is the rate of warming, how quickly the global temperature is increasing. But they also showed the actual temperature of the planet is warmer now than it has been for 70-80 percent of the past over that time period. There have been times when the Earth was warmer, but the important point isn’t the actual temperature, but what it’s doing.

And what it’s doing now is skyrocketing.

Global warming for 11,000 years

The reconstructed global temperature anomaly for the past 11,000 years. The Earth was warm (and warming) in the past, then started to cool…until the last century.

Unfortunately, there’s worse news: Pretty much every prediction by climate scientists shows that this rate will not slow, and in fact may have been underestimated. At Think Progress, Joe Romm took these predictions from climatological literature and projected them into the near future:

The predicted ~8° F rise is not a joke, nor is it some sort of exaggeration for effect. It’s the result of several studies showing just how much human activity is affecting our planet. We’re pumping 30 billion tons of CO2 into the atmosphere every year—100 times as much as all volcanoes combined—and all that carbon dioxide is upsetting the heat balance in our atmosphere. We retain more of the heat from sunlight, and that warms us up. It’s really that simple, despite the frothing from the deny-o-sphere.

And of course, the usual suspects are already trying to decry this new study, but as they always do they have to resort to twisting reality into a Möbius strip. But this is nothing new when it comes to denier claims. Their methods are always the same: cherry-picking data that supports their argument but ignores huge amounts of evidence refuting them, displaying misleading graphs, and out-and-out witch hunts and attacks. If you can’t attack the science, don’t worry, just keep attacking anyway.

The bottom line here is the same as it has been for a long, long time: The planet is warming up. The rate at which the temperature is rising took a huge leap starting a century ago, and it’s due to human activity. We’re seeing the effects now, from the ice caps melting to changes in vegetation growth rates. There is no scientific controversy here, just a manufactured political and ideological one.

And if we don’t accept that and start working toward a solution, now, there won’t be much need to argue any more.

Source: Global warming is real. Let’s get that out of the way right at the start. Climatologist Michael Mann’s bombshell study from years back created the “hockey stick” graph, showing that in the past century, the Earth’s overall temperature spiked, like a case of planetary flu. This study was immediately attacked…