Acidification of the Arctic Ocean is occurring faster than projected according to new findings published in the journal PLoS One. The increase in rate is being blamed on rapidly melting sea ice, a process that may have important consequences for health of the Arctic ecosystem.
Ocean acidification is the process by which pH levels of seawater decrease due to greater amounts of carbon dioxide being absorbed by the oceans from the atmosphere. Currently oceans absorb about one-fourth of the greenhouse gas. Lower pH levels make water more acidic and lab studies have shown that more acidic water decrease calcification rates in many calcifying organisms, reducing their ability to build shells or skeletons. These changes, in species ranging from corals to shrimp, have the potential to impact species up and down the food web.
The team of federal and university researchers found that the decline of sea ice in the Arctic summer has important consequences for the surface layer of the Arctic Ocean. As sea ice cover recedes to record lows, as it did late in the summer of 2012, the seawater beneath is exposed to carbon dioxide, which is the main driver of ocean acidification.
In addition, the freshwater melted from sea ice dilutes the seawater, lowering pH levels and reducing the concentrations of calcium and carbonate, which are the constituents, or building blocks, of the mineral aragonite. Aragonite and other carbonate minerals make up the hard part of many marine micro-organisms’ skeletons and shells. The lowering of calcium and carbonate concentrations may impact the growth of organisms that many species rely on for food.
The new research shows that acidification in surface waters of the Arctic Ocean is rapidly expanding into areas that were previously isolated from contact with the atmosphere due to the former widespread ice cover.
“A remarkable 20 percent of the Canadian Basin has become more corrosive to carbonate minerals in an unprecedented short period of time. Nowhere on Earth have we documented such large scale, rapid ocean acidification” according to lead researcher and ocean acidification project chief, U.S. Geological Survey oceanographer Lisa Robbins.
Globally, Earth’s ocean surface is becoming acidified due to absorption of man-made carbon dioxide. Ocean acidification models show that with increasing atmospheric carbon dioxide, the Arctic Ocean will have crucially low concentrations of dissolved carbonate minerals, such as aragonite, in the next decade.
In the Arctic, where multi-year sea ice has been receding, we see that the dilution of seawater with melted sea ice adds fuel to the fire of ocean acidification” according to co-author, and co-project chief, Jonathan Wynn, a geologist from the University of the South Florida. “Not only is the ice cover removed leaving the surface water exposed to man-made carbon dioxide, the surface layer of frigid waters is now fresher, and this means less calcium and carbonate ions are available for organisms.
Researchers were able to investigate seawater chemistry at high spatial resolution during three years of research cruises in the Arctic, alongside joint U.S.-Canada research efforts aimed at mapping the seafloor as part of the U.S. Extended Continental Shelf program. In addition to the NOAA supported ECS ship time, the ocean acidification researchers were funded by the USGS, National Science Foundation, and National Oceanic and Atmospheric Administration.
Compared to other oceans, the Arctic Ocean has been rather lightly sampled. “It’s a beautiful but challenging place to work,” said Robert Byrne, a USF marine chemist. Using new automated instruments, the scientists were able to make 34,000 water-chemistry measurements from the U.S. Coast Guard icebreaker. “This unusually large data set, in combination with earlier studies, not only documents remarkable changes in Arctic seawater chemistry but also provides a much-needed baseline against which future measurements can be compared.” Byrne credits scientists and engineers at the USF College of Marine Science with developing much of the new technology.
Environmental activist group Generation Alpha has released a video of their confrontation with Aurizon CEO Lance Hockridge. The group’s Over Our Dead Bodies campaign has started targeting Aurizon over their crucial financial and infrastructure role in mining the Galilee Basin in Australia.
The coal mining complex planned for the Galilee Basin is the biggest in the world, and will challenge the Tar Sands as the most damaging resource project on the planet. Mining the Galilee would produce 330 million tonnes of coal, enough to fill a train wrapped around the world one and half times.
The activists visited the CEO at his $4.5 million mansion to place giant carbon footprints coming from his front gate, to demonstrate his personal responsibility for what is seen by the environment movement as an impending environmental catastrophe. He saw the action and approached the activists, accusing them of trespass, even though they were clearly outside his property.
In the confrontation between Lance Hockridge and campaign coordinator Ben Pennings, Hockridge firstly denies the importance of Aurizon. However, when Pennings asks how the mining companies will transport the coal without a rail line the CEO simply says, “That’s a matter for them isn’t it”. Afterwards, Pennings said:
Mining the Galilee Basin is like setting off a bomb. 700 million tons of extra carbon pollution each year is a deadly catastrophe, an environmental crime. CEOs shouldn’t be able to hide behind a corporate entity for their life threatening decisions. We will continue to target Lance Hockridge, to tell the truth about this crime to his neighbours, his community, the world. We will do this and much more till he considers what’s best for the future, not just his wallet.
As if ocean acidification and climate change weren’t troubling enough (both of which are caused by still-rising carbon emissions), new research published in Nature finds that ocean acidification will eventually exacerbate global warming, further raising the Earth’s temperature.
Scientists have long known that tiny marine organisms—phytoplankton—are central to cooling the world by emitting an organic compound known as dimethylsulphide (DMS). DMS, which contains sulfur, enters the atmosphere and helps seed clouds, leading to a global cooling effect. In fact, in the past scientists have believed that climate change may actually increase DMS emissions, and offset some global warming, but they did not take into account the impact of acidification.
Researchers, headed by Katharina Six with the Max Planck Institute for Meteorology, tested how acidification affects phytoplankton in the laboratory by lowering the pH (i.e. acidifying) in plankton-filled water tanks and measuring DMS emissions. When they set the ocean acidification levels for what is expected by 2100 (under a moderate greenhouse gas scenario) they found that cooling DMS emissions fell.
Plugging the results into global modeling system, Six says, “we get an extra warming of 0.23 to 0.48 degree Celsius from the proposed impact [by 2100],” adding that “less sulphur results in a warming of the Earth surface.” This creates a positive feedback loop that will likely have impacts that are anything but positive, according to scientists.
To date, the world has warmed approximately 0.8 degrees Celsius in the last century with a variety of impacts including worsening severe weather, rising sea levels, melting glaciers and sea ice, and imperiled species.
Six also notes that a warmer world does not necessarily mean a more productive world for phytoplankton as has been argued by researchers in the past.
“In former times it was assumed that phytoplankton potentially growth better in a warmer ocean,” she explained to mongabay.com. “However, the basis for plant growth is the supply with nutrients. As the oceans will stabilize in the warmer climate, fewer nutrients will be transported into the sunlight zone. Earth system models, like the MPI-ESM that was used for our study, project a decrease in primary production of 17 percent at the end of this century for a moderate climate scenario. The impact from climate change alone led to a decrease in DMS emission of 7 percent.”
The results are still preliminary as researchers have yet to test how DMS emissions will by impacted in tropical and subtropical waters, focusing to date on polar and temperate waters. In addition, further modeling should be done in order to understand possible uncertainties according to Six.
Still, the evidence is strong enough that the researchers write in the paper that “this potential climate impact mechanism of ocean acidification should be considered in projections of future climate change.” Essentially raising current estimates for a moderate climate scenario by around 10 percent.
Ocean acidification, which has been dubbed “climate change’s equally evil twin” by U.S. National Oceanic and Atmospheric Administration (NOAA)’s Jane Lubchenco, is expected to have largely negative impacts on many marine species, including dissolving the shells of crustaceans and molluscs, hampering coral reefs, and even changing how far fish can hear.
So, how do we stop this from happening?
“There is only one answer,” Katharina Six told mongabay.com, “the abatement of fossil fuel emissions.”
Seven environmental activists today stole a ‘Carbon Bomb’ from the offices of transport company Aurizon (link www.aurizon.com.au) in Brisbane, Australia. The action signified the launch of their shop front hunger strike, pressuring Aurizon to withdraw planned capital from the largest coal complex in the world, planned for the Galilee Basin in their state of Queensland. Burning the coal from this complex is forecast to release over 700 million tons of carbon pollution each year, more than the total emissions Australia, the UK or Canada.
The hunger strike is part of the Over Our Dead Bodies (link www.OverOurDeadBodies.net) campaign, run by 40,000-strong Generation Alpha (link www.facebook.com/GenerationAlpha). Campaign coordinator Ben Pennings told the gathering media:
We’re here because Aurizon plan to bail out debt-ridden Indian company GVK, allowing them to dig up the first 3 coal mines in the Galilee Basin. Mining the Galilee is like setting off a bomb. This amount of carbon pollution is a deadly catastrophe, an environmental crime. So we’ve taken this carbon bomb from Aurizon to symbolize our intentions to stop them.
The campaign is designed to provide unique financial pressure on Aurizon, a rail freight company that specializes in coal. Activists in Australia but also internationally are committing to actions on the campaign website (link www.OverOurDeadBodies.net) that will cost Aurizon significant time and money. These include direct action and civil disobedience aimed at delaying infrastructure, hampering day-to-day operations and even targeting the company’s CEO and board members. Mr. Pennings said:
Aurizon have been ignoring the legitimate concerns of the environment movement for too long. So activists around the country are getting ready for direct action, to make the precarious finances of this complex even more so. Governments aren’t protecting our future, so we will.
The activists included former Australian Senator Andrew Bartlett (link http://en.wikipedia.org/wiki/Andrew_Bartlett). Andrew expressed his frustration with the lack of political engagement on climate change, saying:
We will be on a public hunger strike from today, engaging community members to understand that we can’t have the biggest coal complex on the planet, we can’t ignite this carbon bomb, and still avoid catastrophic climate change. We don’t want short-term mining projects that destroy communities and the environment. We want renewable power and long-term sustainable industries integrated into our communities.
A major survey of the coral reefs of the Caribbean is expected to reveal the extent to which one of the world’s biggest and most important reserves of coral has been degraded by climate change, pollution, overfishing and degradation.
The Catlin scientific survey will undertake the most comprehensive survey yet of the state of the region’s reefs, starting in Belize and moving on to Mexico, Anguilla, Barbuda, St Lucia, Turks & Caicos, Florida and Bermuda.
The Catlin scientists said the state of the regions’ reefs would act as an early warning of problems besetting all of the world’s coral. As much as 80% of Caribbean coral is reckoned to have been lost in recent years, but the survey should give a more accurate picture of where the losses have had most effect and on the causes.
Loss of reefs is also a serious economic problem in the Caribbean, where large populations depend on fishing and tourism. Coral reefs provide a vital home for marine creatures, acting as a nursery for fish and a food resource for higher food chain predators such as sharks and whales.
Stephen Catlin, chief executive of the Catlin Group, said: “It is not only important that scientists have access to this valuable data, but companies such as ours must understand the impact that significant changes to our environment will have on local economies.”
Globally, coral reefs are under threat. The future of the Great Barrier Reef in Australia is in doubt as mining and energy companies want to forge a shipping lane through it to form a more direct link with their export markets.
Warming seas owing to climate change can lead to coral being “bleached” – a state where the tiny polyps that build the reefs die off. The US government’s National Oceanic and Atmospheric Administration predicts increasing frequency and severity of mass bleaching events as global warming takes effect.
Richard Vevers, director of the project, told the Guardian that one important role of the new survey would be to describe a new “baseline” to establish how far such problems have taken their toll to date, which will enable future scientists to judge how degradation – or conservation – progresses.
He said the team of scientists would also probe the underlying reasons for such degradation, with a view to informing conservation efforts.
The team will use satellite data as well as direct observations to assess the reefs. As part of the survey, they will develop software that marine scientists can apply to other reefs around the world. A new camera has been constructed to assist their efforts.
Vevers said: “The Caribbean was chosen to launch the global mission because it is at the frontline of risk. Over the last 50 years 80% of the corals have been lost due mainly coastal development and pollution. They now are also threatened by invasive species, global warming and the early effects of ocean acidification — it’s the perfect storm.”
The planet is undergoing one of the largest changes in climate since the dinosaurs went extinct. But what might be even more troubling for humans, plants and animals is the speed of the change. Stanford climate scientists warn that the likely rate of change over the next century will be at least 10 times quicker than any climate shift in the past 65 million years.
If the trend continues at its current rapid pace, it will place significant stress on terrestrial ecosystems around the world, and many species will need to make behavioral, evolutionary or geographic adaptations to survive.
Although some of the changes the planet will experience in the next few decades are already “baked into the system,” how different the climate looks at the end of the 21st century will depend largely on how humans respond.
The findings come from a review of climate research by Noah Diffenbaugh, an associate professor of environmental Earth system science, and Chris Field, a professor of biology and of environmental Earth system science and the director of the Department of Global Ecology at the Carnegie Institution. The work is part of a special report on climate change in the current issue of Science.
Diffenbaugh and Field, both senior fellows at the Stanford Woods Institute for the Environment, conducted the targeted but broad review of scientific literature on aspects of climate change that can affect ecosystems, and investigated how recent observations and projections for the next century compare to past events in Earth’s history.
For instance, the planet experienced a 5 degree Celsius hike in temperature 20,000 years ago, as Earth emerged from the last ice age. This is a change comparable to the high-end of the projections for warming over the 20th and 21st centuries.
The geologic record shows that, 20,000 years ago, as the ice sheet that covered much of North America receded northward, plants and animals recolonized areas that had been under ice. As the climate continued to warm, those plants and animals moved northward, to cooler climes.
“We know from past changes that ecosystems have responded to a few degrees of global temperature change over thousands of years,” said Diffenbaugh. “But the unprecedented trajectory that we’re on now is forcing that change to occur over decades. That’s orders of magnitude faster, and we’re already seeing that some species are challenged by that rate of change.”
Some of the strongest evidence for how the global climate system responds to high levels of carbon dioxide comes from paleoclimate studies. Fifty-five million years ago, carbon dioxide in the atmosphere was elevated to a level comparable to today. The Arctic Ocean did not have ice in the summer, and nearby land was warm enough to support alligators and palm trees.
“There are two key differences for ecosystems in the coming decades compared with the geologic past,” Diffenbaugh said. “One is the rapid pace of modern climate change. The other is that today there are multiple human stressors that were not present 55 million years ago, such as urbanization and air and water pollution.”
Record-setting heat
Diffenbaugh and Field also reviewed results from two-dozen climate models to describe possible climate outcomes from present day to the end of the century. In general, extreme weather events, such as heat waves and heavy rainfall, are expected to become more severe and more frequent.
For example, the researchers note that, with continued emissions of greenhouse gases at the high end of the scenarios, annual temperatures over North America, Europe and East Asia will increase 2-4 degrees C by 2046-2065. With that amount of warming, the hottest summer of the last 20 years is expected to occur every other year, or even more frequently.
By the end of the century, should the current emissions of greenhouse gases remain unchecked, temperatures over the northern hemisphere will tip 5-6 degrees C warmer than today’s averages. In this case, the hottest summer of the last 20 years becomes the new annual norm.
“It’s not easy to intuit the exact impact from annual temperatures warming by 6 C,” Diffenbaugh said. “But this would present a novel climate for most land areas. Given the impacts those kinds of seasons currently have on terrestrial forests, agriculture and human health, we’ll likely see substantial stress from severely hot conditions.”
The scientists also projected the velocity of climate change, defined as the distance per year that species of plants and animals would need to migrate to live in annual temperatures similar to current conditions. Around the world, including much of the United States, species face needing to move toward the poles or higher in the mountains by at least one kilometer per year. Many parts of the world face much larger changes.
The human element
Some climate changes will be unavoidable, because humans have already emitted greenhouse gases into the atmosphere, and the atmosphere and oceans have already been heated.
“There is already some inertia in place,” Diffenbaugh said. “If every new power plant or factory in the world produced zero emissions, we’d still see impact from the existing infrastructure, and from gases already released.”
The more dramatic changes that could occur by the end of the century, however, are not written in stone. There are many human variables at play that could slow the pace and magnitude of change – or accelerate it.
Consider the 2.5 billion people who lack access to modern energy resources. This energy poverty means they lack fundamental benefits for illumination, cooking and transportation, and they’re more susceptible to extreme weather disasters. Increased energy access will improve their quality of life – and in some cases their chances of survival – but will increase global energy consumption and possibly hasten warming.
Diffenbaugh said that the range of climate projections offered in the report can inform decision-makers about the risks that different levels of climate change pose for ecosystems.
“There’s no question that a climate in which every summer is hotter than the hottest of the last 20 years poses real risks for ecosystems across the globe,” Diffenbaugh said. “However, there are opportunities to decrease those risks, while also ensuring access to the benefits of energy consumption.”
