Stories tagged global warming
Hotter and hotter: This daily temperature map from space shows hotter areas in red, cooler areas in blue. The past century has seen a growing amount of red across the globe.Courtesy NASA/JPLHere's another log to throw on the figurative global climate change fire: a new study shows that recent temperatures are significantly higher than most years since the last ice age some 11,000 years ago. And the trends show that by the end of this century, we'll likely set an all-time high.
Like me, you're probably wondering how researchers can know how cold or warm things were in that time span. Thermometer-measured temperature records only date back to the late 1800s. But temperature information can be gleaned from other datable sources, such as tree rings and isotope ratios in cave formations. Long-chain organic molecules in shells of sea-based microorganisms that settled at the bottom of oceans have also provided temperature clues.
Hockey stick graph: If you were to graph the global temperature data from the last 11,000 year, it would look much like a prone hockey stick, with temperatures of the last 100 years spiking up sharply.Courtesy OhkamiThe new study aggregated data taken from 73 different studies from across the globe to try to get a better handle on overall temperature trends. And that trend shows that in the past century, which started with some of the lowest global temperatures since the last ice age, we've spiked up in recent years to see some of the highest temperatures recorded in that 11,000-year span. Charting that data on a graph over all those years shows a long horizontal line of slight variations ending with a sharp incline over the last century, hence the hockey stick analogy.
Tags : A new angle on climate change education: reaching people through the arts
Twin Cities weather guru Paul Douglas will be leading a panel discussion tomorrow night at the Walker Art Center on new approaches to raising public awareness on climate change. The event is tied to the opening of a new climate change-themed show called This Clement World. The free session starts at 7 p.m. at the Walker and among the panelists is Science Buzz blogger and SMM Director of Global Change Initiatives Patrick Hamilton. City Pages has an interview with Douglas about this new approach to climate change education.
Check out this amazing footage from the documentary, CHASING ICE", and watch a slab of ice the size of lower Manhattan drop off the edge of Ilulissat Glacier in Western Greenland. It's the largest calving event ever filmed. Check out the movie, too, if you haven't yet.
A plankton bloom: Not the new bloom off of Canada, but this is what it looks like. The green stuff in the water is sucking up carbon dioxide and doing ... we don't know exactly what else yet.Courtesy NASAHave you ever wanted to change the world? Of course you have. Who hasn’t? Even JGordon, world renowned for being more or less satisfied with his immediate surroundings, keeps a list of Things I Will Change When I Am King.
Some sample items from the list:
31: No more cake pops. What a joke.
54: Round up the jerks, make them live on Jerk Island.
55: Make sure Jerk Island isn’t actually an awesome place to live.
70: Transform Lake Michigan into biggest ball pit. Cover dead fish with plastic balls.
115: More eyepatches.
262: Regulate burps.
I think you get the idea. As Tears for Fears almost said, everybody wants to change the world.
And we do change it. We change it in a huge way. Cumulatively, the tremendous force of the human race has drastically altered the face of the planet, from oceans to atmosphere. But a lot of that change is sort of accidental; we don’t mean to affect the acidity of the oceans or warm the atmosphere, but we like driving around, making things, using electricity, and all that, and the byproducts of these activities have global effects that we can’t always control.
The notion that we could control these effects is called geoengineering. So we’re accidentally causing global warming … what if we could engineer a global solution to actively cool the planet. We’re causing ocean acidification … what if we could chemically alter the oceans on purpose to balance it out? The trick would be to balance out the positive effects of geoengineering with the potential side effects … if we could even figure out what those side effects are.
Geoengineering is necessarily a really large-scale thing, so for the most part it’s been limited to theoretical projects. But it’s been pointed out that some geoengineering projects would be within the capabilities of not just international bodies or individual countries, but corporations or even wealthy individuals. The Science Museum of Minnesota even has an exhibit on just this possibility: What would you do if you had the wealth to literally change the world?
But there are rules against that sort of thing, and it’s potentially really, really dangerous. So no one would actually do it in the real world ever, right?
Wrong!
Apparently someone did do it. Back in July.
A guy named Russ George, in partnership with a First Nations village, is thought to have dumped about 100,000 kilograms of iron sulfate into the ocean off the Western Coast of Canada. Why iron sulfate? Because iron sulfate is an effective fertilizer for plankton, the microscopic plant-like things in the ocean. The idea is that if you could cause massive growth in plankton, the plankton would suck up a bunch of carbon dioxide from the atmosphere before dying and falling the ocean floor, taking the CO2 with it.
The first part of the plan seems to have worked: satellites have detected an artificial plankton bloom about 6,200 square miles large off the west coast of Canada (which is how the operation was discovered).
George was hoping to make money selling carbon credits gained from the CO2 captured by the plankton, and he convinced the First Nations group involved to put about a million dollars into the project, telling them that it was meant to help bolster the area’s salmon population.
The thing is, it’s really hard to say what dumping almost half a million pounds of iron sulfate into the ocean will do, besides capture some CO2. And, what’s more, it looks like it was illegal: conducted as it was, the operation violates the UN’s Convention on Biological Diversity and the London convention on dumping wastes at sea. Whoops.
So does this spell the end for individually funded geoengineering projects? Or has George’s scheme just opened the door for similar operations?
And, more importantly, is this a good thing or a bad thing? Are people like George taking big steps toward addressing human-caused global change? Or are they creating what I like to call “Pandora’s Frankenstein*”?
Weigh in in the comments, and let us know what you think!
(*My friend Pandora has a pet chinchilla named Frankenstein, and he is horrible. I can’t wait until that chinchilla dies.)
Prehistoric Antarctica shoreline: artist's conception of flora living during the Middle Miocene epoch.Courtesy NASA / JPL-Caltech / Dr. Philip Bart, LSURecent investigations into microfossils show that Antarctica hasn’t been quite the icebox scientists have imagined it to be over the past 34 million years. Pollen and leaf wax samples from Miocene-aged sediments indicate the continent has experienced some periods of warming since the beginning of the most recent glacial period. The core samples studied came from ocean sediments collected near Antarctica, and particulates found in the samples indicate more rain fell on the ice-covered continent during the Middle Miocene epoch (15.5 – 20 million years ago) than previously thought, enough rain to spur the growth of forests of small, stunted trees.
Paleoclimatologist and organic geochemist Sarah Feakins of the University of Southern California and her colleagues analyzed core samples taken from between 144 and 1,100 meters beneath the ocean floor – levels dating back to the Middle Miocene. Spikes of concentrated amounts of pollens and leaf wax appeared in two periods – one about 16.4 million years ago, and another about 15.7 million years ago. The warm periods were relatively short, each lasting less than 30,000 years.
In a previous study, palynologist Sophie Warny of Louisiana State University had first described the pollen and leaf wax spikes found in the core samples, and she and Feakins eventually teamed up for the recent study. The team determined the particle spikes didn’t arise from the leaf wax and pollen blowing in from elsewhere but rather came from two species of trees that once lined the shores of Antarctica. The two species, podocarp conifer and southern beech wouldn’t have grown very tall – maybe knee-high – and neither spreads their pollen over wide areas. Had the pollens blown in from elsewhere - say South America or New Zealand - there were would have been more species in the mix.
Using a mass spectrometer, Feakins and NASA researchers analyzed the ratio of hydrogen to deuterium atoms in the wax molecules which indicated the temperature at the Antarctica location during the two warm periods was about 7 degrees Celsius during the summer. Today, summer temperatures in the same region are about –4 °C. The average global temperature at the time was about 3 °C higher than it is today. As the overall global temperature changes a relatively greater change in polar temperature isn't unexpected due to a process called polar amplification.
The data from Feakins and Warny’s study, which appeared in Nature Geoscience, adds to growing concerns over the sensitivity of Earth’s climatic and hydrological systems. At the moment, no trees line the shores of Antarctica, but current levels of carbon dioxide (393 parts per million) are not far off those thought to have existed during the Middle Miocene’s warm periods (400-600 parts per million) when forests did exist on the margins of the icy continent. This could indicate that even small changes in carbon dioxide levels can are capable of creating big changes in climate.
SOURCES
Earth magazine
Science on NBCnews.com
43 percent melt: This NASA satellite image from July 8 shows 43 percent of the Greenland ice sheet was melting.Courtesy NASAJohnny Carson used to have a standard round of jokes for the summertime on his Tonight Show.
"How hot is it outside today? It's so hot (insert punchline)," was the standard humorous convention he would use.
NASA researchers have a new take on how hot it is this summer, and it's not that funny. Satellite photos taken this month over Greenland show that the massive ice sheet that covers almost all of the Arctic region island was now melting at some degree earlier this month. Like the tried-and-true diet ads in the back of magazines, NASA has before and after satellite images that show the extent of melting that happened.
The top image, complied from three satellite photos taken on July 8, show about 40 percent of the ice sheet's surface was melting. Areas that are pink show where melting is occurring. Areas that are white show non-melting ice and areas that are grey have no ice cover.
97 percent melt: This satellite image from July 12 shows the melt rate surging up to 97 percent.Courtesy NASAThe bottom image, taken on July 12, shows a rapid acceleration of melting on the island, with 97 percent of the ice sheet melting. It's a surge in melting rates that scientists figure happens about once every 150 years. This month's data is the highest melting rate that NASA has seen in Greenland since satellite data has been collected for about 30 years.
A rare warm front stalling over Greenland is the cause of the high amount of melting and by the middle of the month, that front had moved on and things were getting back to normal. You can read the NASA press release about this weather event here.
While the brief massive melting is unusual, it's not a huge immediate threat to Greenland's ice sheet, which is some spots is more than two miles thick.
In other recent Greenland ice sheet news, a huge chunk of coastal ice broke off and is now adrift in the Atlantic Ocean earlier this month. Measuring 59 square miles, the ice sheet is twice the size of Manhattan. You can read more about that story here. Two years ago, an iceberg twice as big as this year's broke off from the same location. Experts say it's extremely rare to have two huge icebergs break loose in such a short amount of time.
It's been a hot one!: an obvious downside of the United States having the warmest spring on record this year. Why is that guy still standing in line?Courtesy Debbi Long via FlickrIt took 102 years but the United States recorded the warmest spring on record, breaking the old record set in 1910. Here are some details from the EarthSky.org website:
Meteorological spring in the northern hemisphere is considered to be during the months of March, April, and May. During these three months, the average temperature across the United States was 57.1 degrees Fahrenheit, which was 5.2 degrees above the long term average. According to the latest information released by NOAA and the National Climatic Data Center (NCDC), spring 2012 is officially the warmest spring ever recorded since records began in 1895. 2012 beat out the year 1910 by a remarkable 2.0 degrees in Fahrenheit in the United States. The period from January through May in the United States saw an average temperature of 49.2°, or 5 degrees above the average. Overall, the United States experienced the second warmest summer, fourth warmest winter, and the warmest spring on record.
Brontosaurs-a-chomping: The constant eating by herds of sauropods like these no doubt produced a constant flow of methane into the atmosphere.Courtesy Public domainImagine you’ve been transported back in time to the Late Jurassic and you’re sitting on a gently sloping hillside watching a large herd of the gigantic sauropod dinosaurs chowing down on tons of vegetation in the valley below. What’s the one thing you might need to worry about? The herd of sauropods suddenly stampeding the hillside? A truck-sized carnivore eyeing you from the shadows? Tiny burrowing mammals gnawing at your ankles? While all these scenarios would have been possible, the most likely worry would probably be (if you’re downwind anyway) getting inundated by a warm blast of dinosaur farts.
That’s right, dinosaur flatulence - tons of it - wafting over you like a huge, stinky old blanket. Ewww.
Researchers from Liverpool John Moore's University, the University of London, and the University of Glasgow have calculated that herds of sauropods, those tiny-headed ,long-necked, long-tailed herbivorous dinosaurs that populated the Jurassic landscape about 150 million years ago, would have been eating a lot of vegetation during their lifetimes and in the process releasing a tremendous amount of methane gas from their guts and into the Earth’s atmosphere. That's a lot of cheese-cutting.
In fact, writing in the journal Current Biology, Dr. David Wilkinson and his colleagues claimed that the amount of emission of methane just from the herbivorous dinosaur gassers would have been about the same amount being emitted from all sources today - 500-520 million tons each year. Methane is a greenhouse gas that can absorb the sun’s infrared energy, and heat up the atmosphere. The producers of methane today range from ruminant species such as cows, goats, and sheep, and from human activities such as natural gas drilling, but the effects on the environment could be similar – a warming of the atmosphere. Back in the Mesozoic, average temperatures were about 18 °F higher than today. Wilkinson and his colleagues suggest the dinosaur backfires could have been a big factor in the warming of the prehistoric environment, but admit it wouldn't have been the only source of the gas back then.
"There were other sources of methane in the Mesozoic so total methane level would probably have been much higher than now," Wilkinson said.
Wilkinson’s research interest lays not so much in the sauropods themselves but in the microscopic bacteria that once lined their guts. It was these microbes that converted the vegetable matter into energy and waste, including methane. Could that vast SBD Mesozoic methane source, as the researchers suggest, have been a big contributor to the warmer temperatures back then? Possibly. Or maybe it's just a lot of hot air.
SOURCE
BBC Nature News
Cumulative impact by humans on the oceanCourtesy National Center for Ecological Analysis and SynthesisOne of the great extinctions in Earth history occurred 252 million years ago when about 95 percent of all marine species went extinct. The cause or causes of the Great Dying have long been a subject of much scientific interest.
Now careful analyses of fossils by scientists at Stanford and the University of California, Santa Crux offer evidence that marine animals throughout the ocean died from a combination of factors – a lack of dissolved oxygen, increased ocean acidity and higher water temperatures. What happened to so dramatically stress marine life everywhere?
Geochemical and fossil evidence points to a dramatic rise in the concentration of carbon dioxide in the atmosphere, which in caused a rapid warming of the planet and resulted in large amounts of carbon dioxide dissolving into the ocean and reacting with water to produce carbonic acid, increasing ocean acidity. The top candidate for all this carbon dioxide? – huge volcanic eruptions over thousands of years in what is now northern Russia.
Why should the Great Dying be of more than just academic interest? Humans currently release far more carbon dioxide into the atmosphere than volcanoes and we are releasing carbon dioxide into the atmosphere at a rate that greatly exceeds that believed to have occurred 252 million years ago. The future of Earth’s oceans will be determined by human decision making, either by default or by design. What do we want our future ocean to be?
Atmospheric carbon dioxide concentration during the past 417,000 yearsCourtesy Wikipedia CommonsSkeptics of human-induced climate change have long pointed to a lag between an increase in temperature and a rise in atmospheric carbon dioxide at the end of the last Ice Age as suggesting that carbon dioxide is an effect of rising temperatures, not a cause. This lag, however, was based on evidence from only one place on Earth - ice core records from Antarctica.
A much more extensive study of paleo-temperature records from 80 sites around the world just published in Nature reveals that global temperature increases followed rises in the carbon dioxide concentration in the atmosphere. Carbon dioxide is a heat-trapping gas that can drive climate change. This study greatly substantiates climate scientists who point out that the enormous quantities of carbon dioxide that human activities are putting into the atmosphere will result in dramatic changes in global climate if they are not curtailed.
