Stories tagged global warming

Mar
12
2013

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.
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/JPL
Here'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.
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 Ohkami
The 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.

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.

Oct
16
2012

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.
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 NASA
Have 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.)

Jul
25
2012

43 percent melt: This NASA satellite image from July 8 shows 43 percent of the Greenland ice sheet was melting.
43 percent melt: This NASA satellite image from July 8 shows 43 percent of the Greenland ice sheet was melting.Courtesy NASA
Johnny 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.
97 percent melt: This satellite image from July 12 shows the melt rate surging up to 97 percent.Courtesy NASA
The 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.

May
02
2012

Cumulative impact by humans on the ocean
Cumulative impact by humans on the oceanCourtesy National Center for Ecological Analysis and Synthesis
One 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?

Apr
10
2012

Atmospheric carbon dioxide concentration during the past 417,000 years
Atmospheric carbon dioxide concentration during the past 417,000 yearsCourtesy Wikipedia Commons
Skeptics 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.

Apr
06
2012

A composed satellite photograph of North America in orthographic projection.
A composed satellite photograph of North America in orthographic projection.Courtesy NASA
The March 30 issue Science summarized an article in a recent issue of Geophysical Research Letters with significant implications for human welfare.

Many climatologists have expected that extreme weather events will increase in frequency and intensity as human activities continue to increase the concentration of heat-trapping gases in the atmosphere. But how in particular could global warming exacerbate extreme weather?

A couple of processes have been identified that are impacting North America. First, the increasing melting of Arctic sea ice in summer means that a tremendous amount of solar energy that in the past was reflected back into space instead is absorbed by the ocean, which in turn warms the overlying atmosphere. Second, snow cover is melting earlier across much of North America and so more solar energy goes into drying out soils. These two processes – Arctic sea ice loss and the heating up and drying out of the interior of the continent – interact to slow the passage of weather systems from west to east across the continent, thereby strengthening their impacts.

Scientists are beginning to figure out how global warming can end up impacting our daily weather.

Apr
08
2011

In the public media, the impacts of global warming have been less important than questioning its causes. And at any rate, reports on the impacts have alternately a catastrophic immediacy or an ambiguous, amorphous quality--the latter likely born out of caution due to the former's inaccuracy and tendency to undermine action. But there's room for a third approach--one of reasonability and inquiry.

And in fact, scientists' explorations go beyond the intangible models of earth covered in gradations of 5 colors, which represent average temperature change over the last century. Their work tests changes in the real world with real organisms. This field work generates data that can be used to test and improve the accuracy of the earth systems models we use to predict future change.
Wheat: I do what I want.
Wheat: I do what I want.Courtesy 3268zauber

One such project is literally heating up wheat fields and spraying CO2 over them. The researchers want to find out how global warming and increasing concentrations of CO2 will impact crops. It turns out that plants will react to these changes differently in different latitudes and climes.

For example, plants in warmer climates might grow better earlier in the year only to take a dive once summer temperatures pass a certain range. Plants in cooler climates might thrive with warmer temperatures and increased CO2, whereas tropical plants might suffer from too much heat.

"There is a narrow latitudinal band that could make rising heat beneficial to growers, Kimball concluded. But farther south, especially in Mexico, the implications of the warming mean serious reductions in crop yields."

Climate model: I get better when you validate me.
Climate model: I get better when you validate me.Courtesy Robert A. Rohde

The information gleaned in these plant studies is helping validate and improve existing models of vegetation so that the tools we need to make decisions about climate change are more accurate. One of the researchers in the article implies that we need a lot more of this validation than we do predictions right now. Even so, changes in reporting on climate change's impacts are often due less to increased uncertainty and more to increased information.

So it seems that rather than the impacts of climate change being universally good or bad, they're a little of both in different parts of the world. What can we do to improve communication in the media on this front?

And to take this a step further, given the varying environmental responses to global warming, it is ethical for one country to make decisions about climate change without consulting other countries?

Mar
29
2011

By the way, when you read about the gigatons of carbon emissions that human activities emit each year, it's helpful to have some perspective:

Let's talk gigatons--one billion tons. Every year, human activity emits about 35 gigatons of [carbon dioxide] (the most important greenhouse gas). Of that, 85% comes from fossil fuel burning. To a lot of people, that doesn't mean much -- who goes to the store and buys a gigaton of carrots? For a sense of perspective, a gigaton is about twice the mass of all people on earth, so 35 gigatons is about 70 times the weight of humanity. Every year, humans put that in the atmosphere, and 85% of that is power. Large actions, across whole nations and whole economies, are required to move the needle.

By comparison, our atmosphere is small--99.99997% of our its mass sits below the Karman line, which is often used to define the border between Earth’s atmosphere and outer space. At 62 miles above Earth's surface, it’s about as high as the distance between St. Paul, MN, and Menomonie, WI.

The oceans also absorb some of that carbon dioxide, but not without consequence.

Of course, the great part about being responsible is having capability--if our inventions bring about such transformations in the air and oceans, then couldn't we be inventive enough to reduce their negative impacts?

Mar
07
2011

You probably know that plants "inhale" carbon dioxide and "exhale" oxygen, but did you know that plants also release water into the air when they exhale? This process is called transpiration, and it plays an important part in our planet's water cycle. I mean, just think of all the billions of plants out there, all of them transpiring 24/7--that really adds up.

Unfortunately, increasing carbon dioxide in the atmosphere has yet another impact on our ecosystems--it reduces transpiration. You see, plants have these tiny pores on the undersides of their leaves called stomata. The stomata open and close depending on the amount of carbon dioxide available in the air and how much they need of it.

It's kind of like your eye's iris--your eye needs an ideal amount of light to see, so when it's bright outside, the iris closes in. This shrinks the pupil so that it only takes in a small amount of light. In lower light, the iris opens, making the pupil larger so that it takes in more light. Like your iris, the stomata open and close to let in the right amount of carbon dioxide.

Stomata: These stomata are from an Arabidopsis plant. The top one is open, and the lower one is closed.
Stomata: These stomata are from an Arabidopsis plant. The top one is open, and the lower one is closed.Courtesy KuriPop

Unfortunately, a recent study showed that with carbon dioxide concentrations increasing quickly, plant stomata are closed longer than they were 150 years ago. There are also simply fewer stomata in leaves. While this controls the amount of carbon dioxide they're absorbing, it has the added outcome of limiting the amount of water released into the air from plants. Over time, this could add up to some significant change--but it's a little early to tell for sure what the impacts will be.

It's kind of amazing to see how changes in carbon dioxide emissions have such far-reaching impacts beyond the one we hear about every day--global warming. Luckily, we have plenty of ways to work on global warming and curtail carbon dioxide emissions, such as cement that absorbs carbon dioxide as it hardens, castles that scrub CO2 from the air, and solar power concentrators that generate 1500 times as much energy as regular solar cells, reducing our dependence on fossil fuels.

What's your favorite way to ditch carbon dioxide?