Courtesy 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?
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?
May I have your attention, please?
(…Will the real Slim Shady please stand up?)
Very funny. But seriously, I’ve got breaking news!
The Institute on the Environment’s Dialogue Earth program is bursting into the online community. With their first press release, Twitter account, Facebook page, YouTube channel, and blog, they’re drawing attention, and new supporters, every day. They've even been featured on The Line, SUNfiltered, The Daily Crowdsource, and Crowdsourcing.org.
Big things, folks. I’m telling ya: big things.
(Um, excuse me, KelsiDayle, but what is Dialogue Earth?)
Oh, gosh. I’m always getting ahead of myself. I’ll allow Dialogue Earth to explain for themselves:
“The Dialogue Earth™ team is working to increase public understanding on timely issues related to the environment by delivering engaging, trustworthy multimedia content to large, diverse audiences.”
Consider these three main ways people gather information about the environment:
Dialogue Earth is developing ways to monitor the ‘chatter’ from each information source.
For example, weather and gas price data sets allow Dialogue Earth to monitor these environmentally-relevant personal experiences.
Twitter provides the Dialogue Earth team with an intriguing sample of peoples’ conversations that have some connection to the environment. Dialogue Earth has developed a method of analyzing Tweets for sentiment through crowdsourcing.
Emerging or social medias, like blogs, are changing our understanding of what’s news, but there are still ways to understand the content, frames, sentiment, and assertions of stories. Dialogue Earth is working on developing a responsive and scalable method for so doing.
Eventually, Dialogue Earth hopes to help people process through the hot topics of the day, but for now Dialogue Earth is focusing on understanding what the big issues are and how people are communicating about them. Knowing these things first should help Dialogue Earth develop additional effective communication tools in the coming months. In fact, Dialogue Earth has already conducted their first experiment in crowdsourcing creative content via Tongal. Check out the winning science video on the topic of ocean acidification below:
Pretty great stuff, huh?
Have you ever heard of ‘ocean acidification’? If not, don’t feel alone. You are in vast majority. A new study by Dr. Anthony Leiserowitz at Yale University found that that just 25 percent of Americans have ever heard of ocean acidification – the process whereby carbon dioxide released into the atmosphere by human activities eventually dissolves into the sea producing carbonic acid which depresses the pH of the ocean. Ocean acidification threatens to dramatically alter marine life if present trends continue. A more informed citizenry is essential if steps are to be taken to address this threat to our futures.
The Science Museum of Minnesota and Fresh Energy on the evening of Thursday, November 4 are hosting the Twin Cities film premiere of the documentary, A Sea Change . The screening of this award-winning, 90-minute film will begin at 6:30 PM followed by Q&A with the film’s director, co-producer, lead NOAA ocean acidification scientist, and Fresh Energy’s science policy director and then concluding with a dessert reception. I hope that you will take advantage of this unique opportunity to see the film and then socialize afterwards. Go to the Science Museum's adult programs to order your tickets.
Courtesy Dana SpinkOn September 2, Dana Spink, grade 6 science teacher from Toledo, OR, became a star when she stepped aboard the oceanographic research vessel, the R/V Kilo Moana (Hawaiian for “oceanographer”) for a week of discovery. She was part of the STARS program (Science Teachers Aboard Research Ships) operated by C-MORE (Center for Microbial Oceanography: Research and Education) at the University of Hawai`i's School of Ocean, Earth Science & Technology.
Courtesy C-MORE Ever since 1988 scientists from UH’s HOT program (Hawai`i Ocean Time-series) have been gathering monthly baseline data from station ALOHA, a deep-water site about 60 miles north of Honolulu. This data lead to the discoveries about rising sea surface temperatures and ocean acidification. Dana and two other teachers were part of this continued ocean chemistry and physics data collection, as they worked alongside shipboard scientists at station ALOHA.
Courtesy Dana Spink
Courtesy C-MORE Dana also came face-to-face with Pacific Ocean micro-critters that were captured in a plankton net. What a variety there were! Some were phytoplankton, the microscopic floating plants of the open ocean, and others were tiny animals belonging to the zooplankton. As a whole, plankton are extremely important to the oceanic ecosystems because they form the base of most food webs. Dana used dichotomous keys from C-MORE's Plankton science kit to identify the open-ocean specimens.
Want to find out more about gadgets and shipboard procedures that the STARS used, like CTDs, fluorometers, flow cytometers and other shipboard procedures? Visit Mrs. Spink's blog!
Water issues are complex and interrelated, so it can be difficult to solve them. But because water is essential to our way of life, we gotta get to work!
Here's an example of how convoluted things can get:
A study at the University of California in Irvine found that freshwater runoff (from precipitation and ice sheet melting) into the oceans has increased significantly--18% more water flowed into the oceans in 2006 compared to 1994. The main problem with this is that the freshwater then becomes saltwater, and we have to wait for it to evaporate and rain onto the ground for it to become drinkable/cookable/agriculturable again. But with global warming, precipitation patterns have changed so that the areas that need water aren't getting as much as they used to.
Speaking of global warming, CO2 in the atmosphere does more than heat things up--it dissolves into the ocean, which makes the water more acidic. This change in pH, though subtle, could become sufficient to kill delicate creatures such as krill in the Southern Ocean within 100 years. Considering that many of the fish we like to eat dine on krill, this could pose a big problem in the future.
But it gets more complicated. The runoff from agricultural fields contains nitogren-based fertilizers, and rivers release tons of it into the ocean each year. The nitrogen fuels an overgrowth of algae, which die when the nitrogen is gone and fall to the seafloor. There, they are consumed by bacteria that thrive and gobble up all the oxygen, creating a "dead zone" where plants and animals cannot live. While human activities add double the natural amount of nitrogen into soils, about 60% of that fertilizer is never used by the plant and ends up in the ocean. Some of it also ends up in the atmosphere, where it becomes N2O--a more powerful greenhouse gas than CO2. This adds to global warming, bringing us back to increased freshwater runoff.
In short, more water is running into the ocean and that water is full of ick that kills stuff and makes more water run into the ocean. Ick.
Much attention and debate is focused on the role of human releases of carbon dioxide (CO2) in global warming and climate change but there is another facet of CO2 that deserves much more attention. Increasing concentrations of CO2 in the atmosphere lead to more and more CO2 dissolving into the oceans where it turns into carbonic acid. A story in the June 18 issue of Science reports that there is no doubt whatsoever that human releases of CO2 are acidifying the oceans at a scale unprecedented in the geologic record.
The closest analogue to present day appears to be the Paleocene-Eocene Thermal Maximum (PETM) of 55.8 million years ago. Over the course of several thousand years, huge amounts of methane and CO2 entered the atmosphere (where the methane was quickly converted to CO2). Much of this CO2 dissolved into the oceans, causing a drop in ocean pH. The difference between the present and the PETM is that human releases of CO2 are occurring at a rate at least ten times faster. At takes about 1,000 years for CO2 dissolved in surface waters to reach the deep sea where sediments eventually neutralize the acid. Human releases of CO2 currently far exceed the rate at which the oceans are able to remove it and so the result is a rapid drop in the pH of surface waters.
Many ocean organisms make their shells from carbonate. Acidification changes carbonate into bicarbonate and hydrogen ions, making the mineral much less available to tropical corals, echinoderms, mollusks, and foraminifera. The danger if ocean acidification continues unabated is potentially dramatic and unpredictable changes in marine life everywhere.
Some policymakers and scientists increasingly are raising the idea of perhaps mitigating the effects of climate change through large-scale geoengineering projects intended to reduce the amount of solar energy reaching the Earth’s surface as a last ditch effort to counteract the effects of greenhouse gas warming. Such projects would do nothing to mitigate the growing problem of our acidifying oceans. The only way to reduce ocean acidification is to reduce globally the quantities of CO2 that humans release into the atmosphere.
Throughout the ongoing debate about exactly how, to what extent, and the ethical implications, the indisputable fact remains that humankind has altered the planet. Back when the human population was only a few thousand strong and agriculture and cooked food were the latest inventions, it was easy for the Joneses to pick up and move camp when the water ran dry, the soil stopped producing tasty wheat, or the garbage piled too high in the backyard. The same can’t be said for the populations of world cities today.
Advances in public health, industry, and agriculture have blown the human population out of the brush. There will soon be 9 billion people on the face of planet Earth! Coupled with rising affluence, our ballooning population’s resource consumption and waste outputs are wrecking havoc on natural systems. New research (see several links below for more info) suggests that within a fixed amount of space, humankind is in danger of causing our own extinction and the only way out is to discard traditional ideas of industrialization and embrace sustainability.
Courtesy Go Gratitude
The first step to bailing out humankind is to investigate how close to failure the world actually is. This was the point of a recent international collaboration: to calculate safe limits for pivotal environmental processes. The key idea here is that of “tipping points,” which can be thought of as thresholds or breaking points. Think about being pestered by your brother or sister: aren’t you able to put up with the annoyance for even a little while before you get so upset you retaliate? That’s your tipping point – the last straw that put you over the edge.
Led by Stockholm Resilience Center’s Johan Rockstrom, a group of European, Australian, and American scientists – including the University of Minnesota’s Institute on the Environment’s director, Jonathan Foley – identified nine processes reaching their tipping points. Three (climate change, nutrient cycles, and biodiversity loss) have already been pushed past their tipping points, four (ocean acidification, ozone depletion, freshwater use, and land use) are approaching their tipping points, and two (aerosol loading and chemical pollution) do not yet have identified tipping points because they require more research. The Institute on the Environment recently released a YouTube video addressing the conclusion of this new research:
Blissfully, there are things we can do to stop hurting the planet and begin patching its wounds. According to Foley’s article, we can’t let ourselves get any closer to the tipping points and piecemeal solutions won’t cut it because of the interconnectedness of the issues. Instead, we should focus on switching to low- or no-carbon fuel sources, stopping deforestation, and rethinking our approaches to agriculture.
The conclusions of this research have been well-accepted, but there has been some criticisms for 1) attempting to establish tipping points at all, and 2) for the appropriateness of the establish tipping points. If you would like more information, including commentaries, please check out the following sources:
Article in Nature: A safe operating space for humanity
Article in Scientific American: Boundaries for a Health Planet
Article in Ecology and Society: Planetary Boundaries: Exploring the Safe Operating Space for Humanity
Two questions to consider as you watch the YouTube video and take a look through the links and articles referenced above are:
1) What are the consequences of being past our tipping points?
2) How do the solutions discussed prevent us from reaching tipping points?
You are encouraged to post your thoughtful answers below!
Courtesy Mark RyanTwo recent stories in the news highlight environmental issues with Earth’s oceans. The first deals with how the oceans’ pH levels are changing at a much faster rate than normally due to increased levels of carbon dioxide (CO2) in the atmosphere. The second concerns the rise of sea levels due to climate change.
With the first story, Prince Albert II of Monaco and over 150 marine scientists are urging world policymakers to confront the problem of ocean acidification. They stated their concerns in the Monaco Declaration, a document that arose from the 2nd International Symposium on the Ocean in a High-CO2 World held in Monaco last October.
According to the Monaco Declaration, the rapid change in seawater chemistry is already measurable and could by mid-century cause oceans to become inhospitable to coral reefs, inhibit calcification in mussels, plankton, and other calcifying organisms, and subsequently harm the fish population to the extent of causing massive deficits in the food source for millions of people.
The world’s oceans have long acted as buffers against CO2 - absorbing up to a third of it - but are now straining to keep up with rising levels of the greenhouse gas. When CO2 dissolves in seawater it causes pH levels to drop, resulting in a more acidic chemistry. Oceans are 30 percent more acidic than before the Industrial Revolution, and in recent years, researchers at Scripps Oceanography have recorded a drop in the pH from 8.16 to 8.05
The declaration warns that only a serious and immediate reduction in CO2 levels will reverse ocean acidification.
You can find more info at the following links:
In the second story, the rise of sea levels due to climate change may actually be a greater threat than previously thought. The potential for rising water from melting ice sheets is not news. Earlier studies have predicted rising ocean levels from the melting of the West Antarctic ice sheet and other ice could, by the end of the century, inundate coastal cities and low-lying areas with up to 3 feet of water.
But previously unrecognized factors are ratcheting up the severity of that number. Authors of a new study say related events triggered by the initial ice melt could cause the sea-levels to rise as much as 21 feet. But it’s really more of a “could happen” rather than a “will happen” situation.
Geophysicist Jerry X. Mitrovica (University of Toronto) and geoscientist Peter Clark (Oregon State) predict not only would the melted ice add more water to the oceans, but also the reduced gravitational pull from the melted (and missing) ice sheet could cause the Antarctic water levels to decrease while northern water levels increased. Also, once the weight of the heavy ice sheet was gone the Antarctic land mass would rebound, pushing more water outward. Finally, the redistribution of water could cause a shift in the Earth’s rotation and potentially push more water northward toward highly populated coastal regions.
University of Toronto physics grad student Natalya Gomez also contributed to the study that appears in the journal Science.