4-10-21 A trek under Thwaites Glacier’s ice shelf reveals specific risks of warm water
Temperature, salinity and other data show the chemistry and path of warm water eroding the ice. The under-ice trek of an autonomous underwater vehicle is giving scientists their first direct evidence for how and where warm ocean waters are threatening the stability of Antarctica’s vulnerable Thwaites Glacier. These new data will ultimately help scientists more accurately project the fate of the glacier — how quickly it is melting and retreating inland, and how far it might be from complete collapse, the team reports April 9 in Science Advances. “We know there’s a sick patient out there, and it’s not able to tell us where it hurts,” says Eric Rignot, a glaciologist at the University of California, Irvine who was not involved in the new study. “So this is the first diagnosis.” Scientists have eyed the Florida-sized Thwaites Glacier with mounting concern for two decades. Satellite images reveal it has been retreating at an alarming rate of somewhere between 0.6 to 0.8 kilometers per year on average since 2001, prompting some to dub it the “doomsday glacier.” But estimates of how quickly the glacier is retreating, based on computer simulations, vary widely from place to place on the glacier, Rignot and other researchers reported in Science Advances in 2019. Such uncertainty is the biggest difficulty when it comes to future projections of sea level rise (SN: 1/7/20). The primary culprit for the rapid retreat of Thwaites and other Antarctic glaciers is known: Relatively warm ocean waters sneak beneath the floating ice shelves, the fringes of the glaciers that jut out into the ocean (SN: 9/9/20). This water eats away at the ice shelves’ underpinnings, points where the ice is anchored to the seafloor that buttress the rest of the glacier against sliding into the sea.
4-9-21 Climate change: Electric trucks 'can compete with diesel ones'
The view that battery-powered heavy goods lorries can't compete with diesel is being challenged by new research. It had been felt that the extra batteries needed for freight would make electric vehicles too expensive. But a new study says that if fast charging networks are built for trucks, then they can beat diesel in terms of cost. With fast charging, the bigger the vehicle, the greater the advantage for electric, say researchers. In the UK, and around the world, there's a strong shift among consumers towards electric-powered cars. Figures for March in the UK saw sales of battery electric and plug-in hybrid cars reach 14% of the market. When it comes to pure electric vehicles, Western Europe is the global hotspot with over 700,000 battery-powered cars sold in 2020. But it is a different story when moving heavy freight. For climate change, this is an important issue. Around 7% of global carbon emissions are generated by heavy transportation trucks. While Tesla and other manufacturers have taken small steps into this market, critics argue that they will struggle to be cost-competitive with diesel. Adding extra batteries to carry the bigger loads just doesn't add up financially is the view. But this new study from the Stockholm Environment Institute (SEI), says that we are looking at the issue the wrong way round. In their research paper, the authors say that fast charging and not bigger batteries is the key to commercial competition for large-scale electric lorries. "If you take that average value, which is our default analysis in the paper, we are really at the tipping point where this starts to make sense," said lead author Björn Nykvist from SEI. "It doesn't really matter [about] the size of the battery pack in the truck. You really just need more power from the charger." "The key here is that, basically, a heavier vehicle consumes more energy. The more energy you consume, the more saving potential there is. So, a very heavy truck uses more diesel per kilometre than a lighter one, but that's also a big savings potential if you can switch to electricity."
4-9-21 COP26: Greta Thunberg says Glasgow summit should be postponed
Greta Thunberg has told the BBC she does not plan to attend the UN climate conference due to be held in Glasgow this November. The 18-year-old Swedish climate campaigner is concerned about the impact of the coronavirus pandemic on attendance at COP26. She believes the summit should be postponed. She says the UK government, which is hosting the summit, should wait until global vaccination rates have risen. The summit will bring together world leaders with the aim of agreeing a plan to tackle climate change. Ms Thunberg's decision is likely to be a significant blow for the UK government. The activist has attended every major climate conference since her first protest outside the Swedish parliament two and a half years ago. She said: "This needs to happen in the right way. Of course, the the best thing to do would be to get everyone vaccinated as soon as possible so that everyone could take part on the same terms." The UN meeting has already been delayed once, from November 2020, and there have been rumours that it may be postponed again. The last two Conference of the Parties (COP) summits have had more than 20,000 attendees and the UK is understood to have been working on the basis that as many as 30,000 people could attend in Glasgow. At the end of last month, sources in Downing Street and Holyrood were adamant that no decision had been made on a further delay to the conference. However, the BBC was told a final decision on whether to delay or move ahead with the summit was likely to be taken shortly after Easter. COP stands for Conference of the Parties, and it is attended by countries that signed the United Nations Framework Convention on Climate Change (UNFCCC) - a treaty agreed in 1994. The 2021 meeting will be the 26th meeting, so it has been named COP26. COP25 was held in Madrid, Spain, in November 2019 and featured a headline speech from Greta Thunberg. It ended with many unresolved issues, but an agreement was made about cutting carbon dioxide - a gas that causes global warming. Each nation agreed to devise a plan to cut their carbon emissions by the next conference in Glasgow.
4-8-21 A third of Antarctic ice shelves risk collapsing due to climate change
Around a third of the ice shelves holding back huge glaciers in Antarctica are at risk of collapse if the world fails to take sufficient action on climate change, new projections have found. The ice shelves circling the continent are vulnerable to meltwater on their surface causing the ice to crack and disintegrate, a process known as hydrofracturing. Computer modelling by Ella Gilbert at the University of Reading, UK, and Christoph Kittel at the University of Liege, Belgium, showed that if the world warms by 4°C since pre-industrial levels, then 34 per cent of the continent’s ice shelves will have meltwater on their surface, a sign they are at risk of collapse. However, the figure falls to 18 per cent if temperature rises are checked at 2°C. The world is currently on track for a 2.9°C rise but, if implemented, climate plans and net zero goals would cut that to 2.1°C. “Warming to 2°C means half the ice shelf area is at risk of collapsing. That is the message: the less the warming the better,” says Gilbert. She and Kittel used a much higher resolution climate model than previous research, with grid squares 35 kilometres across rather than hundreds of kilometres across. It also more accurately represents cloud physics, which is vital as estimates of the area at risk of collapse hinge on how much ice loss is replaced by snowfall. The big difference between the 2°C and 4°C rise scenarios stems from melting outweighing increased snowfall in a 4°C warmer world. The Larsen C ice shelf on the east of the Antarctic Peninsula, where a huge iceberg broke off in 2017, was found to be one of the areas most at risk. “This study shows melting at the ice shelves’ surface will spreads southwards to parts of the continent where huge reservoirs of inland ice may lose their protective barrier. If that happens, we can expect rapid increases in sea level rise along every coastline of our planet,” says Andrew Shepherd at the University of Leeds, UK, who wasn’t involved with the paper.
4-8-21 Australian bushfires warmed the stratosphere by 1°C for six months
Smoke pollution from the 2019–2020 Australian bushfires warmed the stratosphere over the southern hemisphere by at least 1°C for six months, according to a new analysis. The devastating 2019–2020 bushfire season in Australia injected huge amounts of smoke into the stratosphere and led to record aerosol pollution. Yu Pengfei at Jinan University in China and his colleagues used a climate model to simulate the atmospheric smoke movement and its environmental impacts. They found that the smoke remained in the stratosphere for all of 2020, measurably warming the stratosphere by between 1–2 °C , which persisted for approximately six months after the fires. The particles in the bushfire smoke are mainly comprised of organic carbon and black carbon. “The black carbon material in smoke can absorb sunlight and warm the surrounding air,” says Yu. The stratospheric warming would have led to changes in air circulation for the six months that the warming persisted, but the exact effects are unknown, says Yu. The stratosphere – the portion of the atmosphere roughly between 10 and 50 kilometres above the Earth’s surface — also contains the ozone layer. The researchers suggest that the smoke particles also increased the destruction of ozone molecules over the southern hemisphere, reacting in a similar manner as sulphate aerosols. The heating effect of the black carbon would also have contributed by increasing the rate of ozone destruction, adds Yu. This likely contributed to the ozone hole being larger than usual in 2020. The team’s model estimated a drop between August to December 2020 of 10 to 20 Dobson units in total column ozone, a measure of the amount of ozone extending vertically upwards from the Earth’s surface. The average amount of ozone in the atmosphere is roughly 300 Dobson units.
4-7-21 Why rescuing the climate and saving biodiversity go hand in hand
Global warming is a "threat multiplier" for habitats and species already under pressure – by understanding how the problems are linked, we can solve two crises at once. THE Great Barrier Reef is already in a critical state. Rising sea temperatures are killing corals faster than they can recover. As temperatures continue to increase, more and more of the reef will die, along with the rich variety of life and the AUS$6 billion tourism industry that depend on it. It is one headline-grabbing example among many. The continued rapid warming of the planet would wipe out many species, even if it were the only change happening. As it is, a sixth mass extinction in Earth’s history is already under way as farms replace forests and factory ships overfish the oceans. The heating of the planet will push many struggling species over the brink. Some will just have no place left to go. For biodiversity, climate change is, in military jargon, a threat multiplier. Worse still, measures to limit warming often don’t take biodiversity into account. Some, such as the push for biofuels, directly harm it. Yet there is little that is inevitable about what happens next. We might not be able to save all the species under threat, but we can save an awful lot of them. “We could cut the number of extinctions in half,” says John Wiens at the University of Arizona. “I think that’s the biggest cause for optimism.” But our chances are better if we think more smartly about the links between biodiversity loss and climate change, and tackle both of these issues together. Done right, a rescue plan for nature can be part of a plan for saving humanity from the worst of climate change – and vice versa. “Many species are already moving to stay within their comfort zone” The world has warmed around 1°C since pre-industrial times. That is already having a dramatic effect on wildlife. In the Arctic, for example, the loss of more and more sea ice each summer is affecting many animals, from walruses to polar bears.
4-7-21 Britain's electricity system 'greenest ever' over Easter
Great Britain's electricity system was the greenest it had ever been at lunchtime on Easter Bank Holiday Monday, its operator has said. Sunny and windy weather, coupled with low demand for power, led to a surge in renewable sources of energy, National Grid Electricity System Operator said. It meant low-carbon energy sources made up almost 80% of Britain's power. There was no coal generation on the grid and just 10% of power was from gas plants, the operator added. The National Grid Electricity System Operator (ESO) said levels of carbon pollution for each unit of electricity consumed dropped to just 39 grams of carbon dioxide - the lowest ever recorded for the grid - at 13:00 BST on Monday. It said wind power made up 39% of the energy mix, with solar at 21% and nuclear accounting for 16%. The burning of biomass accounted for around 4%. There is debate over the environmental costs of burning biomass, like wood, and the National Grid ESO categorises it separately from low-carbon sources and fossil fuels. By comparison, on Tuesday, 24.8% of Britain's energy came from fossil fuels, most of which was gas (combined cycle), while 45.2% was renewable energy sources. Those fossil fuel figures have been dropping all year. In January, gas accounted for more than 43% of the energy mix, with coal at almost 5%, and then last month just 37% of Britain's electricity was generated from gas. The previous record for Great Britain's greenest day was set during lockdown last year, on 24 May. When Britain went into lockdown, electricity demand plummeted and the National Grid responded by taking power plants off the network and the four remaining coal-fired plants were among the first to be shut down. Last year as a whole saw many records broken for Britain's electricity mix, with an almost 68-day coal-free run between 10 April and 16 June, and solar providing more than a third of electricity supplies on several occasions during May. Christmas 2020 was also the first ever coal-free Christmas Day. Meanwhile, the highest ever amount of electricity generated by wind was on 13 February this year.
4-7-21 Most fuel-hungry SUVs in the UK are bought by people in cities
SUVs in the UK are overwhelmingly bought by people in towns and cities rather than rural areas, with the London borough of Kensington and Chelsea the country’s Range Rover capital. Despite emitting 25 per cent more carbon dioxide on average than a medium-sized car, SUVs have jumped from nearly 7 per cent of private cars sold in the UK in 2009 to more than 21 per cent in 2018. One recent global analysis found the rise of SUVs last year wiped out the environmental gains from electric cars. Now, a new report by environmental charity Possible finds they aren’t even being sold in places where the four-wheel drive and off-roading capabilities of the largest SUV models would be useful. Between 2018 and 2020, 74 per cent of SUVs were registered to buyers with urban addresses, Department for Transport figures show. For the largest class of SUV models, six of the 10 areas registering most sales were affluent London boroughs, including Kensington and Chelsea. And 1 in 10 private cars registered in that borough were Range Rovers, the highest share in the UK. “We stood up the old urban folklore about the ‘Chelsea tractor’, and found Kensington and Chelsea is the home of the SUV. Something has been done to persuade people it’s normal to have a 2-tonne truck to do the shopping,” says Andrew Simms at the New Weather Institute, a co-author of the analysis published today. He says part of the problem is advertising, with SUVs often marketed as a way to protect your family and dominate the road. “The advertising approach has got under people’s fears about living in cities,” he says. Car manufacturers have bigger profit margins on SUVs than other car classes. Simms and Possible say their findings should lead the government to ban advertising for the most polluting third of cars on sale, which would cover most SUVs. They are also calling on advertising firms to reject briefs for polluting SUVs.
4-7-21 City drivers 'should think twice' before buying SUVs
Drivers in crowded cities should think twice before buying a big SUV, says the head of a motoring organisation. Steve Gooding, from the RAC Foundation, said: "We should all choose the right vehicle for the right trip to cut the size of our carbon footprint. "It is right to question if suburban drivers need a car capable of ploughing over rivers, across fields and up steep hills just to pop to the shops." His comments come as research confirms most SUVs are bought by urban drivers. It shows that large SUVs - often known as Chelsea tractors - are indeed most prevalent in places such as Chelsea. They are typically defined by their extreme size, and off-road features such as high ground clearance and four wheel drive. They often face complaints from other road users about their bulk and their pollution - especially during the school run. The report from the think-tank New Weather Institute said: "The numbers stand up long-held suspicions that these vehicles ostensibly designed for off-road are actually marketed successfully to urban users where their big size and higher pollution levels are a worse problem." The report says areas where SUV owners dominate are also the places where road space is most scarce, and where the highest proportion of cars are parked on the street. It says many large SUVs are too big for a standard UK parking space. Andrew Simms, from the New Weather Institute, said: "It turns out that the home of the 'Chelsea tractor' really is Chelsea. One of advertising's biggest manipulations has persuaded urban families that it's perfectly 'normal' to go shopping in a two-tonne truck. "But the human health and climate damage done by SUVs is huge and needs to be undone. Just as tobacco advertising was successfully ended, it's time to stop promoting polluting SUV's." The UK Citizens' Assembly on climate change has supported restrictions on SUVs. But motoring organisations said the analysis was too simplistic.
4-7-21 Greenland election: Opposition win casts doubt on mine
Greenland's main opposition party has won an election which could have major consequences for international interests in the Arctic. The left-wing Inuit Ataqatigiit, which opposes a mining project in southern Greenland, secured 37% of votes. Its leader said on Wednesday that the Kvanefjeld mine, home to major deposits of rare minerals, would not go ahead. The social-democratic Siumut party came second, having been in power for all but four years since 1979. Inuit Ataqatigiit, an indigenous party with a strong environmental focus, will now seek to form a government. Greenland is a vast autonomous arctic territory that belongs to Denmark. Although it has a population of just 56,000, the result of the election has been closely followed internationally. Greenland's economy relies on fishing and subsidies from the Danish government, but as a result of melting ice, mining opportunities are increasing. The company that owns the site at Kvanefjeld, in the south of the country, says the mine has "the potential to become the most significant western world producer of rare earths", a group of 17 elements used to manufacture electronics and weapons. However, disagreement over the project led to the collapse of Greenland's government earlier this year, paving the way for Tuesday's snap election. Many locals had raised concerns about the potential for radioactive pollution and toxic waste in the farmland surrounding the proposed mine. "The people have spoken," Inuit Ataqatigiit's leader Múte Bourup Egede told Danish state broadcaster DR on Wednesday morning, adding that the project would be halted. The head of the Siumut Party, Erik Jensen, told Denmark's TV 2 he believed the controversy surrounding the Kvanefjeld mine was "one of the main reasons" for its defeat, with 29% of the vote. The party had supported the development, arguing that it would provide hundreds of jobs and generate hundreds of millions of dollars annually over several decades, which could lead to greater independence from Denmark.
4-6-21 Greta Thunberg's amazing year meeting the world's climate scientists
“I don’t want you to listen to me, I want you to listen to the science,” says Greta Thunberg in the first episode of a new three-part documentary series about her life. It is a message we have heard before from the 18-year-old. But in Greta Thunberg: A Year to Change the World, we follow the activist as she embarks on a year off school to learn more about herself, get hands-on experience of the consequences of climate change and further explore the science of global warming with the help of the world’s leading scientists. Thunberg has been the figurehead for young climate activists across the world ever since she protested in front of the Swedish parliament building in 2018, aged just 15. Since then, she has inspired thousands of people and challenged policy-makers in her fight against climate change – her impact has even been dubbed “the Greta Thunberg effect”. The first episode of the BBC documentary focuses on Thunberg and her father, Svante, in late 2019 as they travel through North America on their way to the UN COP25 climate conference in Chile. They stop at three key locations that reveal how the environment is changing as a direct result of warming temperatures. First, they visit the Canadian Rockies to investigate why the once lush pine forests there are dwindling. The trees are dying, biologist Brenda Shepherd tells Thunberg, because rising temperatures are increasing the number of mountain pine beetles. Canada is the world’s fourth largest oil producer, employing over 170,000 people. But as a result, some areas of the country are experiencing increases in temperatures twice as fast as the rest of the world. Thunberg emphasises the importance of balancing the trade-off between the strength of the global economy and the health of the planet – something she has repeatedly explained to politicians and industry players alike. To help drive this message home, the series is interspersed with impassioned scientists working across the field, as well as economists who examine what can be done to avert the worst of the climate crisis.
4-6-21 A spike in Arctic lightning strikes may be linked to climate change
Arctic lightning has gotten way more frequent over the last decade amid rising global temperatures, study finds Climate change may be sparking more lightning in the Arctic. Data from a worldwide network of lightning sensors suggest that the frequency of lightning strikes in the region has shot up over the last decade, researchers report online March 22 in Geophysical Research Letters. That may be because the Arctic, historically too cold to fuel many thunderstorms, is heating up twice as fast as the rest of the world (SN: 8/2/19). The new analysis used observations from the World Wide Lightning Location Network, which has sensors across the globe that detect radio waves emitted by lightning bolts. Researchers tallied lightning strikes in the Arctic during the stormiest months of June, July and August from 2010 to 2020. The team counted everywhere above 65° N latitude, which cuts through the middle of Alaska, as the Arctic. The number of lightning strikes that the detection network precisely located in the Arctic spiked from about 35,000 in 2010 to about 240,000 in 2020. Part of that uptick in detections may have resulted from the sensor network expanding from about 40 stations to more than 60 stations over the decade. And just looking at the 2010 and 2020 values alone may overstate the increase in lightning, because “there’s such variability, year to year,” and 2020 was a particularly stormy year, says Robert Holzworth, an atmospheric and space scientist at the University of Washington in Seattle. In estimating the increase in average annual lightning strikes, “I would argue that we have really good evidence that the number of strokes in the Arctic has increased by, say, 300 percent,” Holzworth says. That increase happened while global summertime temperatures rose from about 0.7 degrees Celsius above the 20th century average to about 0.9 degrees C above — hinting that global warming may create more favorable conditions for lightning in the Arctic.
4-6-21 Greenland election: Melting ice and mining project on the agenda
Greenland heads to the polls on Tuesday in snap elections which could have major consequences for international interests in the Arctic. The vast territory, which belongs to Denmark but is autonomous, lies between North America and Europe and has a population of just 56,000. Greenland's economy relies on fishing and Danish subsidies, but melting ice and a planned mine could change the course of the vote - and the territory's future. Here's what you need to know. Disagreement over a controversial mining project in the south of Greenland has split the government and paved the way for this week's election. The company that owns the site at Kvanefjeld says the mine has "the potential to become the most significant western world producer of rare earths", a group of 17 elements used to manufacture electronics and weapons. The Siumut (Forward) Party supports the development, arguing that it would provide hundreds of jobs and generate hundreds of millions of dollars annually over several decades, which could lead to greater independence from Denmark. But the opposition Inuit Ataqatigiit (Community of the People) party has rejected the proposal, amid concerns about the potential for radioactive pollution and toxic waste. The future of the Kvanefjeld mine is significant for a number of countries - the site is owned by an Australian company, Greenland Minerals, which is in turn backed by a Chinese company. Greenland has hit the headlines several times in recent years, with then-President Donald Trump suggesting in 2019 that the US could buy the territory. Denmark quickly dismissed the idea as "absurd", but international interest in the territory's future has continued. China already has mining deals with Greenland, while the US - which has a key Cold War-era air base at Thule - has offered millions in aid.
4-6-21 Light pollution: How lockdown has darkened our skies
One of the positive impacts of lockdown is that there has been a big reduction in light pollution. A nationwide star count found a 10% drop in the amount of people who could only see 10 or fewer stars, an indicator of severe light pollution. Light pollution can impact human health and wildlife by disturbing biological cycles and behaviours. The BBC's Justin Rowlatt visited the Kielder Observatory in Northumberland, an area that benefits from some of the darkest skies in England, to explore the impact of less light.
4-5-21 Piney Point: Emergency crews try to plug Florida toxic wastewater leak
Emergency crews in Florida have been working to prevent a "catastrophic" flood after a leak was found in a large reservoir of toxic wastewater. More than 300 homes near Tampa Bay have been evacuated, and a highway near the Piney Point reservoir has been closed. Florida Governor Ron DeSantis declared a state of emergency on Saturday. On Sunday, he said the water was "primarily saltwater" from a dredging project mixed with "legacy process water and storm water runoff". He added that the water was not radioactive, as had been feared, and that the priority was to prevent a "real catastrophic flood situation". Officials said the 77-acre (31-hectare) reservoir holds millions of gallons of water containing phosphorus and nitrogen from an old phosphate plant. The pond where the leak was found is in a stack of phosphogypsum, a radioactive waste product from the manufacture of fertiliser. Attempts to repair the leak late on Friday, by plugging the hole with rocks and other materials, were unsuccessful. Declaring a state of emergency allowed funds to be released to send more pumps and cranes to the area. On Sunday, Mr DeSantis said emergency workers - assisted by the Florida National Guard - were pumping water out of the pond at a rate of 33 million gallons a day. Other workers have been charting the path to control the flow of the water. Manatee County Administrator Scott Hopes told a press conference on Saturday that there were concerns the water could flood the area, which is mostly agricultural. "We are talking about the potential of about 600 million gallons (2.3 billion litres) within a matter of seconds and minutes, leaving that retention pool and going around the surrounding area," he said. By Sunday, however, he was more optimistic - telling reporters that the situation should be in a "much better position" by Tuesday.
4-4-21 Companies back moratorium on deep sea mining
A long-running dispute over plans to start mining the ocean floor has suddenly flared up. For years it was only environmental groups that objected to the idea of digging up metals from the deep sea. But now BMW, Volvo, Google and Samsung are lending their weight to calls for a moratorium on the proposals. The move has been criticised by companies behind the deep sea mining plans, who say the practice is more sustainable in the ocean than on land. The concept, first envisaged in the 1960s, is to extract billions of potato-sized rocks called nodules from the abyssal plains of the oceans several miles deep. Rich in valuable minerals, these nodules have long been prized as the source of a new kind of gold rush that could supply the global economy for centuries. Interest in them has intensified because many contain cobalt and other metals needed for the countless batteries that will power the electric vehicles of a zero-carbon economy. Dozens of ventures, most of them government-backed, have been exploring vast areas of the Pacific and Indian Oceans to assess their viability for mining. And several companies have developed prototypes of "nodule collectors", giant robotic machines that would drive over the seabed, gathering the rocks and piping them up to ships at the surface. We witnessed one of these devices - called Apollo II - being tested in the waters off southern Spain in 2019. Claudia Becker, a senior BMW expert in sustainable supply chains, tells me what led the car giant to decide against using deep sea metals. "It's the fear that everything we do down there could have irreversible consequences," she said. "Those nodules grew over millions of years and if we take them out now, we don't understand how many species depend on them - what does this mean for the beginning of our food chain? "There's way too little evidence, the research is just starting, it's too big a risk."
4-3-21 World’s largest ocean monitoring system BRUVS launched
Professor Jessica Meeuwig, the Director of the Centre for Marine Futures at the University of Western Australia, has told the BBC about her hopes for a new ocean monitoring system. The UK government funded project, known as BRUVS, will focus on monitoring marine life in ten British Overseas Territories including Pitcairn and Ascension Island.
4-2-21 Then and now: Rising temperatures threaten corals
n our monthly feature, Then and Now, we reveal some of the ways that planet Earth has been changing against the backdrop of a warming world. Here, we look at coral bleaching, and how warming waters are threatening the survival of a true wonder of the seas. Coral reefs are hives of activity in the ocean, where many different species can be found. Scientists refer to such zones as biodiversity hotspots. Although reefs take up less than 1% of the area covered by ocean, they are estimated to be home to more than a third of life under the waves. Yet they too face an uncertain future as a result of a warming world. Scientists list climate change as the main cause of damage to the world's reefs. Corals can't tolerate very high temperatures, so as ocean water warms, they effectively become "sick". Thermal stress of this kind can lead to the coral becoming bleached, meaning they lose their striking colours and turn white or very pale. Coral can survive bleaching events, but in this state they are also more likely to die. The before and after photos show an episode of bleaching and coral mortality in American Samoa, a territory in the Pacific Ocean, back in 2015. A US team of scientists observed at the time: "Severe bleaching and mortality occurred on shallow inshore and [lagoon] reefs along southern Tutuila [American Samoa's main island]. "These shallow habitats have limited water circulation, which worsens the effects of high temperature stress." Despite this worrying event, the state of the reefs in this area are currently deemed to be "good". Coral is an umbrella term for several species of marine invertebrates (animals without backbones). They have a hard outer layer (exoskeleton) made from calcium carbonate - the same stuff shells are made out of. They are found all over the globe, from tropical waters to the freezing polar regions. However, corals only form reefs in the warm, shallow seas of the tropics. The most famous of these is the 2,300km-long Great Barrier Reef, located off the north-eastern shores of Australia. Healthy coral forms a symbiotic relationship with microscopic algae, known as zooxanthellae. In return for being allowed to live in the corals' hard, calcium carbonate exoskeleton, the algae help produce food for their hosts. Zooxanthellae also provide the vibrant colours we associate with healthy coral reefs.
4-2-21 Then and now: Rising temperatures threaten corals
In our monthly feature, Then and Now, we reveal some of the ways that planet Earth has been changing against the backdrop of a warming world. Here, we look at coral bleaching, and how warming waters are threatening the survival of a true wonder of the seas. Coral reefs are hives of activity in the ocean, where many different species can be found. Scientists refer to such zones as biodiversity hotspots. Although reefs take up less than 1% of the area covered by ocean, they are estimated to be home to more than a third of life under the waves. Yet they too face an uncertain future as a result of a warming world. Scientists list climate change as the main cause of damage to the world's reefs. Corals can't tolerate very high temperatures, so as ocean water warms, they effectively become "sick". Thermal stress of this kind can lead to the coral becoming bleached, meaning they lose their striking colours and turn white or very pale. Coral can survive bleaching events, but in this state they are also more likely to die. An episode of bleaching and high coral mortality hit reefs in American Samoa, an island nation in the Pacific Ocean, back in 2015. A US team of scientists observed at the time: "Severe bleaching and mortality occurred on shallow inshore and [lagoon] reefs along southern Tutuila [American Samoa's main island]. "These shallow habitats have limited water circulation, which worsens the effects of high temperature stress." Despite this worrying event, the state of the reefs in this area are currently deemed to be "good". Coral is an umbrella term for several species of marine invertebrates (animals without backbones). They have a hard outer layer (exoskeleton) made from calcium carbonate - the same stuff shells are made out of. They are found all over the globe, from tropical waters to the freezing polar regions. However, corals only form reefs in the warm, shallow seas of the tropics. The most famous of these is the 2,300km-long Great Barrier Reef, located off the north-eastern shores of Australia. Healthy coral forms a symbiotic relationship with microscopic algae, known as zoosthellae. In return for being allowed to live in the corals' hard, calcium carbonate exoskeleton, the algae help produce food for their hosts. Zoosthellae also provide the vibrant colours we associate with healthy coral reefs.
4-2-21 Sydney’s inland suburbs are 10°C warmer than the coast in heat waves
Large-scale weather patterns and urban overheating are interacting to make Sydney’s inland suburbs up to 10°C warmer than coastal areas during extreme heat events. Urban overheating occurs when temperatures in certain parts of an urban environment are comparatively higher than those in surrounding urban areas. The phenomenon occurs as a result of a combination of factors, including heat fluxes linked to human activity and air pollution. What’s more, artificial materials used to build roads, roofs and other urban architecture absorb solar radiation and release it slowly, further heating the air, in a way that trees and other vegetation don’t. Hassan Khan at the University of New South Wales in Sydney and his colleagues have analysed how large weather patterns interact with urban overheating in Sydney. They looked at temperatures in the Sydney central business district (CBD), which is close to the ocean, and compared them with locations in inner Sydney – between 8 and 12 kilometres from the nearest coast – and in western Sydney, between 25 and 50 kilometres inland. The team found that during extreme heat events, the mean daily maximum temperature was between 8 and 10.5°C hotter in western Sydney than in the CBD – despite the fact that the CBD is far more built-up than western Sydney. In inner Sydney suburbs, the mean maximum was 5 to 6.5°C hotter than in the CBD. Sydney, Australia’s most populous city, is located on the east coast of Australia and is also relatively close to desert landforms to the west.As a result, the city experiences “humid–warm” air masses that come from the Pacific Ocean to the east, which are prevalent particularly during the summer months, says Khan. There are also coastal winds that help cool the CBD – but these aren’t able to penetrate inland to reach inner and western Sydney.
4-1-21 Biden is still not taking climate change seriously
His infrastructure plan is ambitious by U.S. standards. That doesn't mean it's enough. President Biden has released the details of his infrastructure plan. It's a big bill — priced at roughly $2.8 trillion over a decade, with tons of money for repairs, maintenance, trains, green investment, and more (as well as a lot of other stuff). It would be paid for with hikes in income and corporate tax rates. A main objective of the plan is supposed to be tackling climate change. Judging by the standards of American politics, it is quite aggressive. But judged by the standards of Biden's campaign platform, and more importantly, by the standards of what is needed to combat climate change, the proposal falls far short of the mark. America will need bolder action than this to do its part in the global fight to preserve a livable climate. First, the good. Biden would invest $85 billion in public transit agencies, $80 billion in Amtrak, and $174 billion in electric vehicles. That's a doubling of federal funding for transit and a quadrupling for intercity rail. He would invest $35 billion in green research directly, and another $155 billion in general research, including advanced energy technology. Most importantly, there are $400 billion in clean energy tax credits for things like wind farms, rooftop solar, home insulation upgrades, and so forth, which will have a climate impact in the trillions. (These credits were mysteriously not included in the administration's headline price tag.) All that is a great stuff. But in terms of climate, this proposal is a substantial downgrade from Biden's campaign pledge — the overall size is about the same, but the priorities are different. The $180 billion in research is welcome, but he previously promised $400 billion focused entirely on climate. There is also $400 billion in elder care, which is welcome of course but has little to do with climate or even infrastructure. The $115 billion for road maintenance, and money to replace every lead water pipe in the country, is similarly vital but largely unrelated to climate. The electric vehicle spending will help, but it lamentably ignores the far greater promise of electric bicycles (though the focus on electric buses and Post Office vehicles is good). At bottom, it isn't really a climate bill — it's a grab bag of some infrastructure stuff, some climate stuff, and some elder care stuff. Despite the large headline price, it isn't that big either — just one percent of GDP. Neither does Biden address the biggest missing element of his campaign's climate plan — international cooperation. Climate change is a global problem, and the U.S. is not even close to the biggest greenhouse gas emitter in the world now. China emits fully twice as much as the U.S., and India emits nearly as much as the entire European Union. The key tasks for global climate policy will be to help or coax China into slashing its emissions, and to prevent the rest of the developing world from following China's coal-powered model. It's a striking absence given that Biden also proposes to revolutionize international corporate taxation. He would institute a 21 percent minimum tax on American corporate taxes, and close many loopholes that allow U.S. companies to book their profits in low-tax foreign countries. More importantly, he proposes to set up a global minimum corporate tax through international agreements. As economist Gabriel Zucman points out, if Biden could get this done (and the U.S. has many ways to pressure other nations to agree, especially given that it would be in their interest anyway), it would end the scourge of beggar-thy-neighbor tax havens which have driven a race to the bottom in corporate tax rates. That's an excellent idea — but it doesn't have anything directly to do with climate.
4-1-21 Climate change: Net zero targets are 'pie in the sky'
Sharp divisions between the major global emitters have emerged at a series of meetings designed to make progress on climate change. India lambasted the richer world's carbon cutting plans, calling long term net zero targets, "pie in the sky." Their energy minister said poor nations want to continue using fossil fuels and the rich countries "can't stop it". China meanwhile declined to attend a different climate event organised by the UK. Trying to lead 197 countries forward on the critical global issue of climate change is not a job for the faint hearted, as the UK is currently finding out. As president of COP26, this year's crucial climate meeting due to take place in Glasgow in November, Britain is charged with ensuring a successful summit of world leaders and their negotiators. To that end, the UK team have embarked on a series of meetings to find the building blocks of agreement, so that the world keeps the temperature targets agreed in Paris in 2015 within reach. To have a decent chance of keeping the increase in global temperature under 1.5C - which is now considered as the gateway to dangerous warming - carbon emissions need to reach net zero by 2050. Net zero refers to balancing out any greenhouse gas emissions produced by industry, transport or other sources by removing an equivalent amount from the atmosphere. A range of major carbon-producing countries, including the US, the UK, Japan and the EU, have signed up to the idea. Last September, China said it would get there by 2060. India, the world's fourth largest emitter, doesn't seem keen to join the club. "2060 sounds good, but it is just that, it sounds good," Raj Kumar Singh, India's minister for power, told a meeting organised by the International Energy Agency (IEA). "I would call it, and I'm sorry to say this, but it is just a pie in the sky." To the discomfort of his fellow panellists, Mr Singh singled out developed countries where per capita emissions are much higher than in India.
4-1-21 These are the 5 costliest invasive species, causing billions in damages
The impact from all invasive species cost the global economy at least $1 trillion since 1970. Invasive species can wreak havoc on local ecosystems. Cleaning up that biological wreckage comes at a big price. These invaders, often thrust into new environments unintentionally (or intentionally, to combat pests) by humans, can transmit new diseases, devastate crops and eat away at crucial infrastructure. From 1970 to 2017, such invasions cost the global economy at least $1.28 trillion in damages and in efforts to control them, researchers report March 31 in Nature. As the globe becomes increasingly interconnected and invasive species take over new habitats, that cost grows. “For decades, researchers have been evaluating the significant impacts of invasive species, but the problem isn’t well known by the public and policy makers,” says Boris Leroy, a biogeographer at the French National Museum of Natural History in Paris. “By estimating the global cost, we hoped to raise awareness of the issue and identify the most costly species.” Leroy and his colleagues screened over 19,000 published papers, ultimately analyzing nearly 1,900 that detailed the costs of various invasions at particular times. The team then constructed a statistical model that estimated yearly costs, adjusting for factors like inflation, different currencies and timescales. Between 1970 and 2017, annual costs roughly doubled every six years, reaching a yearly bill of $162.7 billion in 2017. Intensified global trade over that period gave invaders more opportunities to hitch rides on cargo ships or airplanes, the researchers say. And deforestation and agricultural expansion probably sped their spread by allowing easier access to pristine areas. On the whole, cleaning up the damage caused by invasive species cost $892 billion, about 13 times higher than the $66 billion spent managing invasions, the researchers found.
4-1-21 Flamboyant fishes evolved an explosion of color as seas rose and fell
The feisty fairy wrasses became a neon kaleidoscope thanks to a coral reef "species pump". Fairy wrasses are swimming jewels, flitting and flouncing about coral reefs. The finger-length fishes’ brash, vibrant courtship displays are meant for mates and rivals, and a new study suggests that the slow waxing and waning of ice sheets and glaciers may be partly responsible for such a variety of performances. A new genetic analysis of more than three dozen fairy wrasse species details the roughly 12 million years of evolution that produced their vast assortment of shapes, colors and behaviors. And the timing of these transformations implies that the more than 60 species of fairy wrasses may owe their great diversity to cyclic sea level changes over the last few millions of years, scientists report February 23 in Systematic Biology. can’t help but stand out. They are the most species-rich genus in the second most species-rich fish family in the ocean, says Yi-Kai Tea, an ichthyologist at the University of Sydney. “That is quite a bit of biodiversity,” says Tea, who notes that new fairy wrasse species are identified every year. Despite this taxonomic footprint, Tea says, scientists knew “next to nothing” about the fairy wrasses’ evolutionary history or why there were so many species. To fill this knowledge gap, Tea and his colleagues turned to the fishes’ genetics, extracting DNA from 39 different fairy wrasse species. Many earlier genetic studies on ocean animals in the region focused on a handful of genes in single species, but Tea and his team used a method that isolated nearly 1,000 genes from many species at once. Comparing DNA across species, the researchers reconstructed an evolutionary tree, showing how the dozens of fairy wrasse species are interrelated. The team also estimated how long ago these species split from one another.