All five of Earth’s largest mass extinctions linked to global warming

ENVIRONMENT 22 May 2020
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Ancient marine life may have been wiped out by volcanic activity

Phil Degginger/Carnegie Museum / Alamy

The second-most severe mass extinction in Earth’s history may have been triggered by global warming. The discovery means that, for the first time, all of the largest known extinctions can be linked to a rapid rise in the planet’s temperature.

“It completes the jigsaw puzzle in many ways,” says Andrew Kerr at Cardiff University, UK. Geologists recognise five points in time when huge numbers of species were wiped out, although recent research suggests at least one of these might have been too …

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Read more: https://www.newscientist.com/article/2244353-all-five-of-earths-largest-mass-extinctions-linked-to-global-warming/#ixzz6NIo254Rk

Here’s how a wavy jet stream is screwing up weather all over the US this weekend

A National Weather Service map shows where freeze warnings (navy) are in effect for this weekend.

A National Weather Service map shows where freeze warnings (navy) are in effect for this weekend.
(Image: © NWS)

Temperatures are expected to drop to record lows for this time of year across much of the northern U.S east of the Rocky Mountains. The culprit? A low-pressure mass of Arctic air is making its way down through Ontario, Canada, according to the National Weather Service (NWS).

“Temperatures will be quite chilly for middle May, a good 20 degrees below normal,” on Saturday (May 9), the New York NWS wrote in a Friday forecast discussion. Rain is likely, and flurries are possible, though the mid-May sun makes them unlikely, according to the NWS.

A map shows snowfall predictions for the weekend.

A map shows snowfall predictions for the weekend. (Image credit: NWS)

Farther north and west, things will be colder, with freeze warnings in place across parts of the Great Plains, Appalachians and the Northeast. Several inches of snow are possible in northern Appalachia, according to the national forecast. Lake-effect snow is possible by the Great Lakes, and high winds are expected across the Northeast as the low-pressure system turns into a bona fide storm system.

The air mass making its way south is part of what’s often called the “polar vortex,” a swirl of frigid air usually confined to the Arctic by the circulating atmospheric current known as the jet stream. Sometimes, wobbles in the jet stream allow some of that Arctic air to escape south, according to the NWS.

A National Oceanic and Atmospheric Administration graphic shows how disturbances to the jet stream produce extreme weather.

A National Oceanic and Atmospheric Administration graphic shows how disturbances to the jet stream produce extreme weather. (Image credit: NOAA)

The relationship between polar vortex escapes like this and climate change isn’t yet fully understood, but many studies (summarized in this paper published in the journal Science Advances in 2018) have found climate change effects can disturb the jet stream and lead to extreme weather events.

The Weather Channel reported that this weekend should see multiple low-temperature and possibly low-pressure records fall. Meanwhile, a high-pressure block of lower-latitude air “bulging” northward to the west should bring extreme heat to the other side of the Rocky Mountains.

In other words, it will be an extreme weather weekend all over the country, not fully clearing up after Mother’s Day on Sunday (May 10).

Wildlife Collapse From Climate Change Is Predicted to Hit Suddenly and Sooner

Scientists found a “cliff edge” instead of the slippery slope they expected.

A sea turtle hatchling headed for the ocean in Aceh Province, Indonesia.
Credit…Chaideer Mahyuddin/Agence France-Presse — Getty Images

Climate change could result in a more abrupt collapse of many animal species than previously thought, starting in the next decade if greenhouse gas emissions are not reduced, according to a study published this month in Nature.

The study predicted that large swaths of ecosystems would falter in waves, creating sudden die-offs that would be catastrophic not only for wildlife, but for the humans who depend on it.

“For a long time things can seem OK and then suddenly they’re not,” said Alex L. Pigot, a scientist at University College London and one of the study’s authors. “Then, it’s too late to do anything about it because you’ve already fallen over this cliff edge.”

The latest research adds to an already bleak picture for the world’s wildlife unless urgent action is taken to preserve habitats and limit climate change. More than a million plant and animal species are at risk of extinction because of the myriad ways humans are changing the earth by farming, fishing, logging, mining, poaching and burning fossil fuels.

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The study looked at more than 30,000 species on land and in water to predict how soon climate change would affect population levels and whether those levels would change gradually or suddenly. To answer these questions, the authors determined the hottest temperature that a species is known to have withstood, and then predicted when that temperature would be surpassed around the world under different emissions scenarios.

ImageCoral bleaching on the Great Barrier Reef. Scientists say recent bleaching events suggest that major die-offs in tropical seas are already underway.
Credit…James Cook University Australia/Agence France-Presse — Getty Images

When they examined the projections, the researchers were surprised that sudden collapses appeared across almost all species — fish, reptiles, amphibians, birds and mammals — and across almost all regions.

“It’s not that it happens in some places,” said Cory Merow, an ecologist at the University of Connecticut and one of the study’s authors. “No matter how you slice the analysis, it always seems to happen.”

If greenhouse gas emissions remain on current trajectories, the research showed that abrupt collapses in tropical oceans could begin in the next decade. Coral bleaching events over the last several years suggest that these losses have already started, the scientists said. Collapse in tropical forests, home to some of the most diverse ecosystems on earth, could follow by the 2040s.

But if global warming was held to below 2 degrees Celsius, the number of species exposed to dangerous climate change would drop by 60 percent. That, in turn, would limit the number of ecosystems exposed to catastrophic collapse to about 2 percent.

“The benefits of early and rapid action are massive and prevent the extinction of thousands of species,” said Christopher H. Trisos, a scientist at the University of Cape Town and one of the study’s authors.

The study does not take into account other factors that could help or hurt a species’ survival. For example, some species may tolerate or adapt to higher temperatures; on the other hand, if their food sources could not, they would die off just the same.

Climate Fwd: What on earth is going on? Get the latest news about climate change, plus tips on how you can help.

“It provides yet another, critical wake-up call about the massive repercussions of a rapidly warming world,” said Walter Jetz, an ecologist at Yale University who did not participate in the study. He added that it was more evidence of the importance of following through on the pledges that nations around the world made in the Paris Agreement on climate change. The Trump administration is in the process of withdrawing from that commitment.

The study suggested that even keeping global warming to less than 2 degrees Celsius, in accordance with the Paris Agreement, would still leave many people and ecosystems vulnerable.

“If we take action now, we limit this abrupt disruption to 2 percent of the planet,” Dr. Trisos said. “But that two percent of the planet still has a lot of people living there in tropical regions. And they need our help.”

Catrin Einhorn reports on wildlife and extinction for the Climate desk. She has also worked on the Investigations desk, where she was part of the Times team that received the 2018 Pulitzer Prize for Public Service for its reporting on sexual harassment. @catrineinhorn

A version of this article appears in print on , Section A, Page 19 of the New York edition with the headline: Study Sees ‘Cliff Edge’ Of Die-Offs Over Climate. Order Reprints | Today’s Paper | Subscribe

Abrupt Warming – How Much And How Fast?

SATURDAY, MAY 13, 2017

https://arctic-news.blogspot.com/2017/05/abrupt-warming-how-much-and-how-fast.html

How much could temperatures rise? As the image shows, a rise of more than 10°C (18°F) could take place, resulting in mass extinction of many species, including humans.

How fast could such a temperature rise eventuate? As above image also shows, such a rise could take place within a few years. The polynomial trend is based on NASA January 2012-February 2017 anomalies from 1951-1980, adjusted by +0.59°C to cater for the rise from 1750 to 1951-1980. The trend points at a 3°C rise in the course of 2018, which would be devastating. Moreover, the rise doesn’t stop there and the trend points at a 10°C rise as early as the year 2021.

Is this polynomial trend the most appropriate one? This has been discussed for years, e.g. at the Controversy Page, and more recently at Which Trend Is best?

The bottom part of above image shows the warming elements that add up to the 10°C (18°F) temperature rise. Figures for five elements may be overestimated (as indicated by the ⇦ symbol) or underestimated (⇨ symbol), while figures in two elements could be either under- or overestimated depending on developments in other elements. Interaction between warming elements is included, i.e. where applicable, figures on the image include interaction based on initial figures and subsequently apportioned over the relevant elements.

A closer look at each of these warming elements further explains why abrupt warming could take place in a matter of years. As far as the first two elements are concerned, i.e. the rise from 1900 and the rise from 1750 to 1900, this has already eventuated. The speed at which further warming elements can strike is depicted in the image below, i.e. the rise could for a large part occur within years and in some cases within days and even immediately.

Assessing the Danger

The danger can be looked at on three dimensions: timescale, probability and severity. On the severity dimension, a 10°C temperature rise is beyond catastrophic, i.e. we’re talking about extinction of species at massive scale, including humans. On the probability dimension, the danger appears to be progressing inevitably toward certainty if no comprehensive and effective action is taken.

In terms of timescale, a 10°C temperature rise could eventuate within a matter of years, which makes the danger imminent, adding further weight to the need to start taking comprehensive and effective action, as described in the Climate Plan.

The Threat

With little or no action taken on global warming, it appears that the Antropocene will lead to extinction of the very human beings after which the era is named, with the Anthropocene possibly running from 1950 to 2021, i.e. a mere 71 years and much too short to constitute an era. In that case a better name for the period would be the Sixth Extiction Event, as also illustrated by the image below.

[ See: Feedbacks in the Arctic and the Extinction page ]

In conclusion, it’s high time that homo sapiens starts acting as genuinely wise modern human beings and commit to comprehensive and effective action as discussed at the Climate Plan.

Further reading

Read more about the threat here. Warming elements are discussed in more detail at the Extinction Page, while specific elements are also discussed in posts, e.g. methane hydrates are discussed at Methane Erupting From Arctic Ocean, decline of the snow and ice cover and associated feedbacks is discussed at Arctic Ocean Feedbacks and less take-up by oceans of CO₂ and heat from the atmosphere is discussed at 10°C or 18°F warmer by 2021? and at the new post High Waves Set To Batter Arctic Ocean.

The situation is dire and calls for comprehensive and effective action as described in the Climate Plan.

Links

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

• Feedbacks
https://arctic-news.blogspot.com/p/feedbacks.html

• Extinction
https://arctic-news.blogspot.com/p/extinction.html

• The Threat
https://arctic-news.blogspot.com/p/threat.html

• Controversy
https://arctic-news.blogspot.com/p/controversy.html

• Which Trend Is best?
https://arctic-news.blogspot.com/2017/03/which-trend-is-best.html

• 10°C or 18°F warmer by 2021?
https://arctic-news.blogspot.com/2017/04/10c-or-18f-warmer-by-2021.html

• Arctic Ocean Feedbacks
https://arctic-news.blogspot.com/2017/01/arctic-ocean-feedbacks.html

• Methane Erupting From Arctic Ocean
https://arctic-news.blogspot.com/2017/03/methane-erupting-from-arctic-ocean-seafloor.html

• High Waves Set To Batter Arctic Ocean
https://arctic-news.blogspot.com/2017/06/high-waves-set-to-batter-arctic-ocean.html

• Warning of mass extinction of species, including humans, within one decade
https://arctic-news.blogspot.com/2017/02/warning-of-mass-extinction-of-species-including-humans-within-one-decade.html

2°C crossed

FRIDAY, MARCH 13, 2020

https://arctic-news.blogspot.com/2020/03/2c-crossed.html

It’s time to stop denying how precarious the situation is.

Remember the Paris Agreement? In 2015, politicians pledged to hold the global temperature rise to well below 2°C above pre-industrial levels and pledged they would try and limit the temperature rise to 1.5°C above pre-industrial levels. Well, an analysis by Sam Carana shows that it was already more than 1.5°C above pre-industrial when the Paris Agreement was reached.

In Sam Carana’s analysis, the year 1750 is used as the baseline for pre-industrial. The analysis shows that we meanwhile have also crossed the 2°C threshold (in February 2020) and that the temperature rise looks set to rapidly drive humans and eventually most if not all species on Earth into extinction.

Yet, our politicians refuse to act!

Accelerating temperature rise

Indeed, there are indications that the recent rise is part of a trend that points at even higher temperatures in the near future, as also discussed at this analysis page. Polynomial trends can highlight such acceleration better than linear trends. The 1970-2030 polynomial trend in the image below is calculated over the period from 1880 through to February 2020. The trend points at 3°C getting crossed in 2026.

In above image, the January 2020 and February 2020 anomalies are above the trend. This indicates that the situation might be even worse.

A polynomial trend calculated over a shorter period can highlight short-term variation such as associated with El Niño events and can highlight feedbacks that might otherwise be overlooked. The 2010-2022 trend in the image below is calculated with 2009-Feb.2020 data. The trend indicates that 2°C was crossed in February 2020, and looks set to keep rising and cross 3°C in 2021, more specifically in January next year, which is less than a year away.

Such a steep rise is in line with unfolding developments that are causing the aerosol masking effect to fall away, such as a decrease in industrial activity due to COVID-19 fears. The image below shows a potential rise of 18°C or 32.4°F from 1750 by the year 2026.

Above image was posted more than a year ago and illustrates that much of this potentially huge temperature rise over the next few years could eventuate as a result of a reduction in the cooling now provided by sulfates. In other words, a steep temperature rise could result from a decline in industrial activity that is caused by fears about the spread of a contagious virus, as also discussed in the video at an earlier post.

The situation is dire and calls for immediate, comprehensive and effective action, as described in the Climate Plan.

Links

• Analysis: Crossing the Paris Agreement thresholds
https://arctic-news.blogspot.com/p/crossing.html

• A rise of 18°C or 32.4°F by 2026?
https://arctic-news.blogspot.com/2019/02/a-rise-of-18c-or-324f-by-2026.html

• How much warming have humans caused?
https://arctic-news.blogspot.com/2016/05/how-much-warming-have-humans-caused.html

• Arctic Ocean January 2020
https://arctic-news.blogspot.com/2020/02/arctic-ocean-february-2020.html

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

In the video below, Guy McPherson discusses the situation.

Coronavirus: Why are planes still flying?

Plane landing at Heathrow AirportImage copyrightGETTY IMAGES

You’ve only got to look up to see there’s still a fair amount of activity in the air, despite all the airline cutbacks. Why is that?

Surprisingly, a number of global airlines are still running passenger flights, including British Airways (BA).

That’s despite aviation largely grinding to a halt as the coronavirus crisis hit passenger traffic numbers and governments banned flights.

But tens of thousands of Britons stranded abroad will be flown home under a new government agreement, while many planes carry essential cargo.

Have the number of flights been cut?

Passenger flights are believed to have been cut by up to 95%, but that still means one in 20 are taking off.

Airlines say they are keeping vital links open.

“We are working with European Union (EU) governments to try to keep some minimum flight links open for emergency reasons, even though the passenger loads on these flights will be very low,” said Ryanair.

Empty planeImage copyrightGETTY IMAGES
Image captionThe coronavirus outbreak has had a severe impact on demand for air travel

But other flights are to bring stranded people home.

BA, Virgin Atlantic, EasyJet, Jet2 and Titan are among airlines that have agreed to fly Britons back to the UK.

“We are doing everything we can to bring customers home, including critical workers,” BA told the BBC.

“Not all governments are allowing flights. We are working with the Foreign Office to open routes where we can.”

The UK government has also pledged £75m to help provide charter flights to bring UK nationals back from countries where commercial flights aren’t available.

Dominic Raab
Image captionThe UK Foreign Secretary Dominic Raab announced a deal between government and airlines to return Britons stranded by coronavirus on Monday

BA is already operating a number of repatriation flights chartered by the Foreign Office from Lima, Peru.

Are airports and planes safe for travellers?

Heathrow Airport said it is working closely with Public Health England officials “to facilitate their access to the airport so that they can implement their enhanced monitoring measures as a precaution.

“In line with the latest Public Health England advice, we are encouraging passengers and colleagues to maintain good hand hygiene.”

Meanwhile, Ryanair said all its aircraft “are disinfected daily”.

“With low loads, social distancing will be optimised on-board,” the airline said.

Banner image reading 'more about coronavirus'
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How many flights are there?

That’s difficult to find out, but you can check at any airport’s website to see how many planes are flying in and out at any given time.

When the BBC checked Heathrow Airport – heathrow.com/departures – on Monday morning, for instance, there were flights scheduled in the following hour or so to Dublin, Copenhagen, Bahrain, Manchester, Helsinki, Amsterdam, Warsaw, Madrid, Hamburg, Moscow, Barcelona, Doha, Berlin, Paris, Kuala Lumpur, Valencia, Boston and Stockholm.

You can also see at-a-glance live data of how many flights are in the air at any one time through flight tracker website flightradar24.com.

But many flights you see in the sky will be cargo planes. The amount of cargo handling via Heathrow Airport has doubled in recent days, it told the BBC.

What do cargo planes carry?

They often carry vital supplies, including food and medical equipment.

For example, two-fifths of the UK’s pharmaceutical products such as medicines, vaccines and respirators are imported via Heathrow Airport.

The airport is the UK’s largest port by value, with 34% of the country’s cargo passing through.

Normally 95% of the cargo that comes into Heathrow Airport is carried in the belly-hold of passenger planes, but the airport is currently “repurposing its operation and scaling up its cargo offering”.

It has temporarily increased the number of dedicated cargo flights.

“These will bring in vital supplies of food and medical equipment to help Britain weather this storm,” said Heathrow boss John Holland-Kaye.

Last week it reported a 243% increase in the number air traffic movements carrying only cargo.

During normal operations, the airport usually handles 47 cargo-only planes a week, on average.

On Tuesday 31 March, it is forecast to have 48 cargo-only planes in just one day.

Recipe For Disaster

Consider this blog a chronicle of mankind’s last days. What were humans thinking when they took this incredibly beautiful, fragile, planet down—in the name of greed, selfishness, arrogance, sport or self-esteem?

Some of the articles I post might seem unrelated, off-topic or out of place when examined alone. But they are all part of the bigger picture which someday may be viewed by a higher intelligence who comes across it in their quest to know just how one species—out of so many—thought they had the right to exploit all others, carte blanc, under the narcissistic delusion that non-human lives on Earth had no rights at all.

Whether or not mankind survives the assault they’re putting the planet through is a non-issue for me. Personally, I hope they don’t. They do not deserve a second chance to rule this vibrant, watery orb any more than they deserved the first chance to steal Nature, abuse and forever change her.

But why all this on an anti-hunting blog? Because hunting, and ultimately meat-eating, is where humans first started screwing things up. For a plant-eating primate to leave the trees, take weapon in hand, turn carnivorous and claim the planet and everything that walks, crawls, swims or flies as their own was a recipe for disaster…

‘The only uncertainty is how long we’ll last’: a worst case scenario for the climate in 2050

The Future We Choose, a new book by the architects of the Paris climate accords, offers two contrasting visions for how the world might look in thirty years (read the best case scenario here)

 Christiana Figueres, author: ‘This is the decade and we are the generation’

Red clouds in a dark sky
 ‘The air can taste slightly acidic, sometimes making you feel nauseated.’ Photograph: Arctic-Images/Corbis

It is 2050. Beyond the emissions reductions registered in 2015, no further efforts were made to control emissions. We are heading for a world that will be more than 3C warmer by 2100

The first thing that hits you is the air. In many places around the world, the air is hot, heavy and, depending on the day, clogged with particulate pollution. Your eyes often water. Your cough never seems to disappear. You think about some countries in Asia, where, out of consideration, sick people used to wear white masks to protect others from airborne infection. Now you often wear a mask to protect yourself from air pollution. You can no longer simply walk out your front door and breathe fresh air: there might not be any. Instead, before opening doors or windows in the morning, you check your phone to see what the air quality will be.

Fewer people work outdoors and even indoors the air can taste slightly acidic, sometimes making you feel nauseated. The last coal furnaces closed 10 years ago, but that hasn’t made much difference in air quality around the world because you are still breathing dangerous exhaust fumes from millions of cars and buses everywhere. Our world is getting hotter. Over the next two decades, projections tell us that temperatures in some areas of the globe will rise even higher, an irreversible development now utterly beyond our control. Oceans, forests, plants, trees and soil had for many years absorbed half the carbon dioxide we spewed out. Now there are few forests left, most of them either logged or consumed by wildfire, and the permafrost is belching greenhouse gases into an already overburdened atmosphere. The increasing heat of the Earth is suffocating us and in five to 10 years, vast swaths of the planet will be increasingly inhospitable to humans. We don’t know how hospitable the arid regions of Australia, South Africa and the western United States will be by 2100. No one knows what the future holds for their children and grandchildren: tipping point after tipping point is being reached, casting doubt on the form of future civilisation. Some say that humans will be cast to the winds again, gathering in small tribes, hunkered down and living on whatever patch of land might sustain them.

More moisture in the air and higher sea surface temperatures have caused a surge in extreme hurricanes and tropical storms. Recently, coastal cities in Bangladesh, Mexico, the United States and elsewhere have suffered brutal infrastructure destruction and extreme flooding, killing many thousands and displacing millions. This happens with increasing frequency now. Every day, because of rising water levels, some part of the world must evacuate to higher ground. Every day, the news shows images of mothers with babies strapped to their backs, wading through floodwaters and homes ripped apart by vicious currents that resemble mountain rivers. News stories tell of people living in houses with water up to their ankles because they have nowhere else to go, their children coughing and wheezing because of the mould growing in their beds, insurance companies declaring bankruptcy, leaving survivors without resources to rebuild their lives. Contaminated water supplies, sea salt intrusions and agricultural runoff are the order of the day. Because multiple disasters are often happening simultaneously, it can take weeks or even months for basic food and water relief to reach areas pummelled by extreme floods. Diseases such as malaria, dengue, cholera, respiratory illnesses and malnutrition are rampant.

The aftermath of a wildfire in northern California, November 2018.
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 The aftermath of a wildfire in northern California, November 2018. Photograph: Noah Berger/AP

You try not to think about the 2 billion people who live in the hottest parts of the world, where, for upwards of 45 days per year, temperatures skyrocket to 60C (140F), a point at which the human body cannot be outside for longer than about six hours because it loses the ability to cool itself down. Places such as central India are becoming increasingly challenging to inhabit. Mass migrations to less hot rural areas are beset by a host of refugee problems, civil unrest and bloodshed over diminished water availability.

Food production swings wildly from month to month, season to season, depending on where you live. More people are starving than ever before. Climate zones have shifted, so some new areas have become available for agriculture (Alaska, the Arctic), while others have dried up (Mexico, California). Still others are unstable because of the extreme heat, never mind flooding, wildfire and tornadoes. This makes the food supply in general highly unpredictable. Global trade has slowed as countries seek to hold on to their own resources.

Countries with enough food are resolute about holding on to it. As a result, food riots, coups and civil wars are throwing the world’s most vulnerable from the frying pan into the fire. As developed countries seek to seal their borders from mass migration, they too feel the consequences. Most countries’ armies are now just highly militarised border patrols. Some countries are letting people in, but only under conditions approaching indentured servitude.

A young boy picks material from a rubbish dump in Taez, Yemen.
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 A young boy picks material from a rubbish dump in Taez, Yemen. Photograph: Ahmad Al-Basha/AFP via Getty Images

Those living within stable countries may be physically safe, yes, but the psychological toll is mounting. With each new tipping point passed, they feel hope slipping away. There is no chance of stopping the runaway warming of our planet and no doubt we are slowly but surely heading towards some kind of collapse. And not just because it’s too hot. Melting permafrost is also releasing ancient microbes that today’s humans have never been exposed to and, as a result, have no resistance to. Diseases spread by mosquitoes and ticks are rampant as these species flourish in the changed climate, spreading to previously safe parts of the planet, increasingly overwhelming us. Worse still, the public health crisis of antibiotic resistance has only intensified as the population has grown denser in inhabitable areas and temperatures continue to rise.

The demise of the human species is being discussed more and more. For many, the only uncertainty is how long we’ll last, how many more generations will see the light of day. Suicides are the most obvious manifestation of the prevailing despair, but there are other indications: a sense of bottomless loss, unbearable guilt and fierce resentment at previous generations who didn’t do what was necessary to ward off this unstoppable calamity.

 This is an edited extract from The Future We Choose: Surviving the Climate Crisis by Christiana Figueres and Tom Rivett-Carnac, published by Manilla Press (£12.99). To order a copy go to guardianbookshop.com. Free UK p&p over £15

 Christiana Figueres and Tom Rivett-Carnac will be in conversation at a Guardian Live event at the Royal Geographical Society, London SW7, on Tuesday 3 March, 7pm

Scientists show solar system processes control the carbon cycle throughout Earth’s history

Scientists show solar system processes control the carbon cycle throughout Earth's history
Geologists studying the Lower Jurassic (Pliensbachian) Belemnite Marl Member mudstone succession in Dorset, UK, showing orbitally paced variations of the sediment composition similar to the studied core in Wales. Credit: Dr Micha Ruhl

https://phys.org/news/2020-02-scientists-solar-carbon-earth-history.html

The world is waking up to the fact that human-driven carbon emissions are responsible for warming our climate, driving unprecedented changes to ecosystems, and placing us on course for the sixth mass extinction event in Earth’s history.

Using chemical data from ancient mudstone deposits in Wales, an international team involving scientists from Trinity College Dublin discovered that periodic changes in the shape of Earth’s orbit around the Sun were partly responsible for changes in the carbon-cycle and global climate during and in between the Triassic-Jurassic Mass Extinction (around 201 million years ago, when around 80% of the species on Earth disappeared forever) and the Toarcian Oceanic Anoxic Event (around 183 million years ago).

In addition, volcanic activity released large amounts of greenhouse gases into the oceans and atmosphere at that point in time, which resulted in major global carbon cycle perturbations as well as  and environmental change.

Dr. Micha Ruhl, Assistant Professor in Sedimentology at Trinity, said:

“Our work shows that for the 18 million years or so in between the Triassic-Jurassic mass extinction and the Toarcian Oceanic Anoxic Event, Earth’s global carbon-cycle was in a constant state of change.”

Scientists show solar system processes control the carbon cycle throughout Earth's history
Eccentricity of the Earth’s orbit around the Sun. The fluctuation between a nearly circular and elliptical orbit drives cyclic changes in the Earth’s environment, including the global carbon cycle. Credit: Marisa Storm

“Periodic changes in the shape of Earth’s orbit around the sun impacted on the amount of energy received by Earth from the sun, which in turn impacted climatic and environmental processes, as well as the carbon-cycle, on local, regional and global scales.”

“Although this phenomenon is well known for having caused the glacial cycles in more recent times, the present study shows that these external forcing mechanisms on Earth’s systems were also operating, and controlling Earth’s carbon cycle in the distant past, even during non-glacial times when Earth was marked by hot-house climate conditions.”

Present-day orbital configurations and solar system processes should have resulted in a future return to glacial conditions. However, anthropogenic carbon release will likely have disrupted this natural process, causing rapid global warming, rather than a steady return to cooler climates.

The study of past global change events, such as the end-Triassic mass extinction and the Toarcian Oceanic Anoxic Event, as well as the time in between, allows scientists to disentangle the different processes that control global  cycle change and constrain tipping points in Earth’s climate system.

A major international research team, made up of scientists from across Europe, North and South America and China, and including Dr. Micha Ruhl and other researchers from Trinity, will soon commence drilling a 1 km deep borehole to retrieve rock samples.

These samples will comprise detailed climatic and environmental information and allow for further improved understanding of the processes that led to past major global change events and mass extinctions. Drilling of this borehole will occur as part of the International Continental Drilling Program.

Bumblebees’ decline points to mass extinction – study

Populations disappearing in areas where temperatures are getting hotter, scientists say

Bumblebee
 The study used data on 66 bumblebee species across North America and Europe. Photograph: Natalia Fedosenko/Tass

Bumblebees are in drastic decline across Europe and North America owing to hotter and more frequent extremes in temperatures, scientists say.

A study suggests the likelihood of a bumblebee population surviving in any given place has declined by 30% in the course of a single human generation. The researchers say the rates of decline appear to be “consistent with a mass extinction”.

Peter Soroye, a PhD student at the University of Ottawa and the study’s lead author, said: “We found that populations were disappearing in areas where the temperatures had gotten hotter. If declines continue at this pace, many of these species could vanish forever within a few decades.”

The team used data collected over a 115-year period on 66 bumblebee species across North America and Europe to develop a model simulating “climate chaos” scenarios. They were able to see how bumblebee populations had changed over the years by comparing where the insects were now to where they used to be.

Dr Tim Newbold, of University College London’s Centre for Biodiversity & Environment Research, said: “We were surprised by how much climate change has already caused bumblebee declines. Our findings suggest that much larger declines are likely if climate change accelerates in the coming years, showing that we need substantial efforts to reduce climate change if we are to preserve bumblebee diversity.”

Bumblebees play a key role in pollinating crops such as tomatoes, squash and berries. The researchers say their methods could be used to predict extinction risk and identify areas where conservation actions are needed.

Prof Jeremy Kerr, of the University of Ottawa and the study’s senior author, said: “This work also holds out hope by implying ways that we might take the sting out of climate change for these and other organisms by maintaining habitats that offer shelter, like trees, shrubs or slopes, that could let bumblebees get out of the heat.

“Ultimately, we must address climate change itself and every action we take to reduce emissions will help.”

The research is published in the journal Science.