Earth's Shifting Crust Linked to Climate Change, Scientists Propose
By Tim Radford
Movements of the earth's crust may mean that global warming driven by greenhouse gases from power stations and vehicle exhausts isn't the only threat to life the world faces.
About 700 million years ago, global temperatures fell so low that glaciers may have reached the equator. Snowball Earth may have all but extinguished life on the planet. But the only life at the time was microbial and dispersed in the oceans.
The planet survived: volcanic eruptions may have darkened the ice and pumped more carbon dioxide and steam into the atmosphere, and the world warmed again.
But, say two Texan scientists, the frozen plane in what geologists call the Neoproterozoic era may have been precipitated at the start by the first dramatic movements in the earth's crust or lithosphere, known as plate tectonics. That is, shifts in climate and shifts in the earth's crust could be linked.
"Earth is the only body in our solar system known to currently have plate tectonics, where the lithosphere is fragmented like puzzle pieces that move independently," said Robert Stern, a geoscientist at the University of Texas at Dallas.
All other rocky planets so far observed are shielded by a single "lid": one outer sphere of rock that seals any liquid or molten interior. But the earth's surface is alive, continuously interacting with the atmosphere and the oceans, and perhaps making life itself possible, as well as precarious.
Professor Stern and Nathan Miller at the University of Texas at Austin report in the journal Terra Nova that there could be at least 22 ways in which the movement of tectonic plates could have delivered a calamitous drop in planetary temperatures, and they propose that until about 700 or 800 million years ago, the planet's crust was rigid.
Only in the Neoproterozoic did the tectonic plates start moving, to grind into each other, build mountains, set the rocks quivering, ignite eruptions and set up weather systems that accelerated erosion and drew down carbon dioxide into rock carbonates, eventually to trigger a dramatic form of global cooling.
Research like this is tentative: the authors offer a hypothesis to be challenged, rather than a theory to be confirmed. But research like this is fundamental: to understand the subtleties of the present climate, now inexorably being altered by human action, it is necessary to understand change in the past as well, and to establish the principles that control the planet's overall climate history.
In the same spirit, other scientists have confirmed that greenhouse gas emissions could in theory make the planet uninhabitable, that the presence of life on Earth means the planet could perhaps never freeze entirely and that the changes already wrought by humanity make another Ice Age less likely.
The Texas study's most radical proposal is a new date for the commencement of tectonic activity, relatively late in the planet's history. The idea that Earth was all but covered with ice has been confirmed in various ways. What is new is the suggestion that the movements of the Earth's surface might have triggered a climate convulsion.
"In the present day, climate is in the news because we're changing it by putting more carbon dioxide into the atmosphere," said Stern. "But imagine a time when Earth didn't have plate tectonics, and it then evolved to have plate tectonics—that would have been a major shift in the Earth's operating system, and it would have had a huge effect on climate, too."
Climate Change Could Set Off Volcanoes https://t.co/UsDcXQFT0Q @YEARSofLIVING @ClimateReality @MichaelEMann @UCSUSA @DeSmogBlog— EcoWatch (@EcoWatch)1523554680.0
Reposted with permission from our media associate Climate News Network.
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By Jason Bruck
Human actions have taken a steep toll on whales and dolphins. Some studies estimate that small whale abundance, which includes dolphins, has fallen 87% since 1980 and thousands of whales die from rope entanglement annually. But humans also cause less obvious harm. Researchers have found changes in the stress levels, reproductive health and respiratory health of these animals, but this valuable data is extremely hard to collect.
Researchers work with trained dolphins to learn more about their sensory abilities, seen here testing a dolphin's hearing. Jason Bruck / CC BY-ND
A Lot to Learn From Hormones<p>When sampling the blow, we are looking for hormones in mucus as these can be used to gauge psychological and physiological health. We are specifically interested in <a href="https://dx.doi.org/10.1371%2Fjournal.pone.0114062" target="_blank">hormones like cortisol</a> and <a href="https://doi.org/10.1016/j.ygcen.2018.04.003" target="_blank">progesterone</a>, which indicate stress levels and reproductive ability respectively, but can also help determine overall health.</p><p>Additionally, blow samples can detect <a href="https://dx.doi.org/10.1128%2FmSystems.00119-17" target="_blank">respiratory pathogens</a> in the lungs or nasal passages - blowholes evolved from noses after all.</p><p>This health analysis is especially important in areas with oil spills as the chemicals can cause hormonal problems that harm <a href="https://www.carmmha.org/investigating-how-oil-spills-affect-dolphins-and-whales/" target="_blank">development, metabolism and reproduction</a> in dolphins.</p><p>Hormone samples can provide scientists with valuable data, but collecting them from intelligent and unpredictable animals is challenging.</p>
Cetacean Collaborators<p>To build a drone that can stealthily collect spray from moving dolphins, we needed more data on their eyesight and hearing, and this is data that couldn't be collected in the wild nor simulated in a lab.</p><p>We worked with dolphins at facilities like Dolphin Quest in Bermuda, which provides guests opportunities to learn about dolphins while allowing <a href="https://dolphinquest.com/about-us/our-story/" target="_blank">scientists access to animals for noninvasive research</a>. Here the dolphins can swim away if they choose not to work with us, so we had to design the study like a game; the way a kindergarten teacher entertains a class. If the dolphins aren't interested, we don't get to do the science.</p><p>Over the course of hundreds of sessions, we sought to answer two questions: What can dolphins hear and what can they see around their heads?</p><p>To test dolphin hearing, we set up microphones and cameras to record dolphin behavior as we played drone noise in the air. We analyzed the responses to each noise – such as how many dolphins looked at the speaker – and used these as a proxy for their ability to hear the sounds.</p>
<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="5f31daf07a652b8d64a093b993ee4e96"><iframe lazy-loadable="true" src="https://www.youtube.com/embed/UjmQeH3vXHI?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Robodolphin doesn't look like a real dolphin, but it doesn't need to in order to train our drone pilots. C.J. Barton / Oklahoma State University / CC BY-ND<p>To build robodolphin, we worked with dolphins trained to "chuff" or sneeze on command to measure spray characteristics. We used high-speed photography to see the dolphins' breath as it moved through the air. Then we conducted high resolution CT scans of a dolphin head and 3D-printed a replica of a nasal passage.</p><p>Now, we have a complete robodolphin and are tweaking its sprays to be nearly identical to the real thing. This will allow us to determine how close we need to get to collect the samples, and therefore, how quiet our drone needs to be.</p>
The replica dolphin blowhole was designed from a scan of a real blowhole passage, and the spray it produces closely matches the real thing. Alvin Ngo, Mitch Ford and CJ Barton / Oklahoma State University / CC BY-ND
A Bit of Practice, Then Into the Wild<p>In the next few months, we will test flights over robodolphin with existing drones to determine the timing and strategy for collection. From there, we will fabricate a low-noise drone that can fly fast enough and with sufficient maneuverability to capture samples from wild dolphins. Like a video game, we will use the visual field data to develop approach trajectories to stay in the visual blindspots.</p><p>We plan to test our drones on a truck-mounted robodolphin moving down a runway, then using a boat to simulate realistic conditions. The next steps will involve ocean testing with dolphins trained for open ocean swimming. These tests will determine if our devices can catch and hold the hormones as the drone flies back to a researcher's boat.</p><p>Finally, we will deploy the system to collect data on wild dolphins. Our first goal is to test resident dolphins – animals that live on the coasts and deal directly with boat and oil industry noise – which will allow us to learn more about stress resulting from human impacts.</p><p>Those samples are a way off, but if all goes well we will have a specially built drone capable of flying long distances and capturing samples undetected in a few years. The samples collected will allow researchers to do better science with impact on the animals they study.</p>
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Billions worth of valuable metals such as gold, silver and copper were dumped or burned last year as electronic waste produced globally jumped to a record 53.6 million tons (Mt), or 7.3 kilogram per person, a UN report showed on Thursday.
Environmental and Health Hazard<p>Experts say e-waste, which is now the world's fastest-growing domestic waste stream, poses serious environmental and health risks.</p><p>Simply throwing away electronic items without ensuring they get properly recycled leads to the loss of key materials such as iron, copper and gold, which can otherwise be recovered and used as primary raw materials to make new equipment, thereby reducing greenhouse gas emissions from extraction and refinement of raw materials.</p><p>Refrigerants found in electronic equipment such as fridge and air conditioners also contribute to global warming. A total of 98 Mt of CO2-equivalents, or about 0.3% of global energy-related emissions, were released into the atmosphere in 2019 from discarded refrigerators and ACs that were not recycled properly, the report said.</p><p>E-waste contains several toxic additives or hazardous substances, such as mercury and brominated flame retardants (BFR), and simply burning it or throwing it away could lead to serious health issues. Several studies have linked unregulated recycling of e-waste to adverse birth outcomes like stillbirth and premature birth, damages to the human brain or nervous system and in some cases hearing loss and heart troubles.</p><p>"Informal and improper e-waste recycling is a major emerging hazard silently affecting our health and that of future generations. One in four children are dying from avoidable environmental exposures," said Maria Neira, director of the Environment, Climate Change and Health Department at the World Health Organization. "One in four children could be saved, if we take action to protect their health and ensure a safe environment."</p>
Europe Leads the Way<p>While most of the e-waste was generated in Asia (24.9 Mt) in 2019, Europe led the charts on a per person basis with 16.2 kg per capita, the report said.</p><p>But the continent also recorded the <a href="https://www.dw.com/en/the-eu-declares-war-on-e-waste/a-51108790" target="_blank">highest documented formal e-waste collection and recycling</a> rate at 42.5%, still below its target of 65%. Europe was well ahead of the others on this front. Asia ranked second with 11.7%.</p><p>The authors said while more that 70% of the world's population was covered by some form of e-waste policy or laws, not much was being done toward implementation and enforcement of the regulations to encourage the take-up of a collection and recycling infrastructure due to lack of investment and political motivation.</p><p>"You have to think about new economic systems," said Kühr.</p><p>One approach could be that consumers no longer buy the products, but only the service they offer. The device would remain the property of the maker, who would then have an interest in offering his customers the best service and the necessary equipment. The maker would also be interested in designing his products in such a way that they are easier to repair and easier to recycle, Kühr said.</p>
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