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Think It’s Hot Now? Wait Until We Reach Hothouse Earth #auspol #qldpol #heatwave #StopAdani #NoNewCoal #ClimateChange now #ClimateCrisis @SciNate

Think It’s Hot Now? Wait Until We Reach Hothouse Earth

Steven Salzberg7:30 am

The river bed of the Rhine is dried on August 8, 2018 in Duesseldorf, western Germany, as the heatwave goes on. (Photo credit: PATRIK STOLLARZ/AFP/Getty Images)

It’s getting hotter all over the planet.

This week the temperature in Bar Harbor, Maine, reached 91° F (32.8° C).

In my 20 years vacationing here, this is easily the hottest weather I’ve ever experienced.

Up and down the U.S. east coast, cities are sweltering, and temperatures out west are even hotter, with California seeing all-time high temperatures, including the hottest July on record in some areas, which has fed damaging fires across the state. Death Valley is always hot, but this week has been crazy, with temperatures on August 7 reaching 122° F (50° C).

At the same time, Europe is baking under a “heat dome” that has brought unprecedented high temperatures, including 45° C (113° F.) in Portugal. It’s so hot that people aren’t even going to the beach.

Global warming is here, folks.

I know we’re supposed to call it “climate change,” because it’s much more complex than simply warming, but warming is one of the most obvious consequences.

And yes, a single heat wave doesn’t prove anything, and weather is not the same as climate. I know. But a just-released study from Oxford University found that climate change made this summer’s heat wave in Europe twice as likely.

And now, a new study published last week in the Proceedings of the National Academy of Sciences, says it could get much, much hotter if we don’t do something about it.

In this paper, an international team of climate scientists led by Will Steffen and Hans Joachim Schellnhuber explain that, thanks to human activities, the planet is well on its way to a “Hothouse Earth” scenario.

In a Hothouse Earth, global average temperatures would rise 4–5° C (7–9° F) and sea levels will rise 10–60 meters (33–200 feet) above today’s levels.

This would be catastrophic for many aspects of modern civilization.

Many agricultural regions would become too hot and arid to sustain crops, making it impossible to feed large swaths of humanity.

Low-lying coastal areas would disappear or become uninhabitable without massive engineering efforts, displacing hundreds of millions of people. As Steffen et al. put it:

“The impacts of a Hothouse Earth pathway on human societies would likely be massive, sometimes abrupt, and undoubtedly disruptive.”

That’s putting it mildly.

One reason this scenario is happening, as the study explains, is that we are very close to “tipping points” beyond which certain changes cannot be stopped. (We may have already passed some of them.)

These include losing the Arctic ice cap in the summer, and losing the Greenland ice sheet permanently: because they are basically white, these massive expanses of ice serve as giant reflectors to send much of the sun’s heat back into space. Without the ice, the darker planet surface absorbs far more heat, creating a positive feedback effect. Another example is the melting of the permafrost, land that has been frozen for thousands of years and that contains a great deal of carbon in the form of methane. Once that methane is released, it will create further warming.

We are also likely to lose the Amazon rainforest, all of our coral reefs, and huge swaths of boreal forests. (See here for a global map of these tipping points.)

If this seems grim, Steffen and colleagues point out that we still have time to avoid it. They propose that societies must act collectively to create a “Stabilized Earth” at no more than 2° C above pre-industrial levels, which is possible but not easy:

“Stabilized Earth will require deep cuts in greenhouse gas emissions, protection and enhancement of biosphere carbon sinks, efforts to remove CO2 from the atmosphere, possibly solar radiation management, and adaptation to unavoidable impacts of the warming already occurring.”

None of this is beyond our abilities.

We know what we need to do, but it requires large-scale, coordinated action that many governments must agree on if it’s to have an impact.

Unfortunately, humans (and our governments) tend to do nothing until faced with an emergency, and the tipping points leading to a Hothouse Earth may not look like emergencies, not at first. For example, Arctic sea ice has been declining steadily for 25 years or more, but because few people are aware of this (and even fewer experience it first hand), it doesn’t seem urgent.

Yet it is.

So perhaps this summer’s heat wave can serve as a wake-up call that we need to pay more attention to our planet’s health. Otherwise it’s going to get a lot hotter.

Steven Salzberg is the Bloomberg Distinguished Professor of Biomedical Engineering, Computer Science, and Biostatistics at Johns Hopkins University.

I’m the Bloomberg Distinguished Professor of Biomedical Engineering, Computer Science, and Biostatistics at Johns Hopkins University. From 2005-2011 I was the Horvitz…MORE

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The hot-headed deniers of #climatechange #auspol #qldpol #StopAdani #NoNewCoal

The hot-headed deniers of climate change

By Mick O’Reilly, Foreign Correspondent,

Published: 17:09 August 9, 2018

Ramachandra Babu/©Gulf News

One thing you can say about the Underground system in London is that is it the quickest way of getting around the city of 10 million. But the quickest does not equate with the most comfortable.

As summer temperatures have soared across northern Europe — meteorologists are predicting the mercury could hit 50 degrees Celsius in parts of southern Spain and Portugal now, the hottest temperatures recorded there since weathermen started keeping track of such things.

As a result, it’s got downright stinky and hot riding the Tube.

Because London and the United Kingdom generally aren’t used to such hot summers — the last one nearly as warm and for nearly as long was back in 1976, the previous in 1961 — there is no air-conditioning as the trains on the District, Circle, Piccadilly lines and the rest trundle through the bowels of what feels like the outer circles of Hell, given the stifling temperatures.

In northern England, there hasn’t been anything like normal rainfall for months, and farmers who are hard-pressed to give their herds of livestock sufficient water have been granted special permission to take more supplies from rivers.

Canals that cross the nation used to be the mainstay of the transportation system before the advent of railways. Now, those canals are running low on water, the lock systems to raise and low narrowboats from one level to the next aren’t functioning, and those boats are scraping off the beds of the waterways anyway.

In Manchester, the water shortage has also highlighted a fact that for every litre of water in the pipes under the roads and footpaths, half of it is lost in leaks and poorly maintained infrastructure.

If there is one plus in this litany of summer woes, it is that archaeologists have taken to the skies above England and, because of the wilting fields and virtually non-existent moisture content, have been able to distinguish the outlines of long-lost Roman and Saxon settlements in those parched pastures.

In Ireland, a nation that’s normally known for its greener-than-green grass and its gloomy clouds and intermittent rain, there’s a drought. Householders in Dublin and other cities have been prohibited from watering their lawns, and the water works authority has asked people to refrain from anything that might use up dwindling water sources.

In the Irish agricultural system, the nation’s dairy farmers are expected to see their annual incomes cut by half because of the weather.

Earlier this week, temperatures in Germany got so hot that fish in the River Rhine simply stopped swimming and died. In two days alone, a quarter of the annual permissible fish catch that’s normally taken from the waterway by fishermen and anglers was simply lost because the fish simply floated to the surface and gave up in the bath-like water.

In Switzerland, cows have died of thirst and grass growth is so poor now on those Alpine slopes, Swiss authorities are permitting the importation of hay for fodder from Germany and Austria.

In Sweden, a nation known for its forestry and timber products, summer fires spawned by the high temperatures have consumed 20,000 hectares of woodland, and the summer heat has changed the official high point of that nation because the glacier tip on Mount Kebnekaise melted. Its summer berry season is a write-off, it’s simply too hot for the fruits to come to fruition.

Around the Mediterranean, it’s even hotter, with pavements on some Spanish and Portuguese roads breaking up as the asphalt surface melted.

But it’s not just Europe that’s experience hot temperatures. In Quebec, some 70 people died there in July as a direct result of summer temperatures exceeding 40 degrees Celsius.

Sure, for readers of Gulf News in the Arabian Gulf, the temperatures in Europe and the hot and prolonged summer conditions might raise an eyebrow — and certainly readers from the Indian subcontinent might be used to such extreme climatic conditions. The reality is that Europeans are not. And nor is their infrastructure, economies, agricultural production systems, road and transport networks, trains or even canals.

Yes, climate analysts have said that 2018 will be the hottest year on record, with some towns inside the Arctic Circle recording unprecedented temperatures of above 30 degrees Celsius.

Not only are temperatures higher, but weather patterns are also more erratic. Across France, there have been severe thunderstorms, with so much rain falling so quickly that drainage and retention systems are overwhelmed. Simply put, there’s too much rain falling too quickly for it to be used to end the alternative periods of drought experienced there.

The Dutch, who for centuries have fought a battle with Mother Nature to prevent the sea from inundating their lands, now find themselves with too little water in their dykes, undermining the carefully crafted and engineered system that keeps the sea out.

Sure, everyone loves a sunny summer. Now the question every European must face is when is too much sun too much?

2018 must go down as the year when the effects of climate change and global warming became a reality.

Ten years ago, the European Union first set out to try and tackle climate change, and the 28 members have broadly adopted the “Triple 20” strategy by 2020, pledging to cut greenhouse gases by 20 per cent, increasing its share of renewable energy by 20 per cent, and increasing energy efficiency by 20 per cent.

For environmentalists and climate-change advocates, who point to this summer as a need for urgent and more extensive change, the Triple 20 is too low. The reality, though, is that change happens slowly in Europe. Hopefully, the events of this simmer from the Baltic to the Balearics, the Canary Islands to Central Europe, might just be enough for more urgent action.

Now, all a climate denier has to do is simply take a Tube train from Euston to Embankment to experience first-hand what global warming feels like. And we’d better get used to it.

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A wasted decade that could have cost us the earth. #auspol #qldpol #nswpol #ClimateChange #StopAdani #drought #wildfire #heatwave

Jan Fran on The Feed

The lack of leadership from both sides of politics on climate change has caused electricity prices to soar and next to no climate action. The lost decade may have been our only chance to prevent catastrophic climate change.

Now all the headlines are screaming record drought, wildfires & heatwaves.

One tabloid in the U.K says it all.

There has been a total collapse of political leadership in many of the world’s leading democracies. We are now facing a climate crisis that many climate scientists fear we may not recover.

We have already warmed the planet by 1C and we are quickly going to find ourselves on a 4C planet a temperature that humanity may not survive.

We are now in the Anthropocene an era that may see the end of human civilisation.

Runaway #climatechange could trigger ‘Hothouse Earth’ with 200ft sea level rises! #auspol #qldpol #nswpol #StopAdani #NoNewCoal @SciNate #Drought #Heatwave #Wildfire Join the dots!

Runaway climate change could trigger ‘Hothouse Earth’ with 200ft sea level rises, warn scientists!

By Sarah Knapton

6 AUGUST 2018 • 8:00 PM

Earth may be on a runaway trajectory towards a ‘hothouse’ climate which will see huge swathes of the planet become uninhabitable and 200ft sea level rises, an international team of scientists has warned.

A new review found that even if targets to cap global warming at 2C are met, it may already be too late because of a ‘domino effect’ of other factors such as the ongoing reduction in Arctic sea ice and the deforestation of the Amazon rainforest.

Press link for more: Telegraph.co.uk

Many parts of the earth could become uninhabitable!

‘Many parts of Earth could become uninhabitable’: Study’s grim warning

Blake Foden7 August 2018 — 9:05am

Many parts of Earth could become uninhabitable for humans, with the planet at risk of entering an irreversible “hothouse” climate.

That’s the alarming warning from an international team of scientists, including Australian National University professor Will Steffen, in a study published on Tuesday.

Current targets may not stop global warming domino effect

A new study says that the global warming target set at the 2015 Paris climate agreement may be too little to stop catastrophic temperature rises.

As large parts of eastern Australia battle drought and Europe is gripped by a heatwave, Professor Steffen said current efforts to combat global warming would not be enough to meet the emission-reduction targets set by governments in the Paris Agreement, which may be insufficient to prevent the dangerous scenario anyway.

The study warns that Earth is already more than halfway towards the point of no return.

Global average temperatures are just over one degree above pre-industrial temperatures, but rising by 0.17 degrees every 10 years.

Professor Steffen said if temperatures rose to two degrees above pre-industrial levels, a level within Paris Agreement targets, it could trigger natural processes that would cause further warming of the Earth even if all human emissions ceased.

If that happened, global average temperatures may reach up to five degrees above pre-industrial levels – the hottest temperatures experienced in more than 1.2 million years.

Sea levels could also rise between 10 and 60 metres, threatening coastal areas.

“Many parts of the planet could become uninhabitable for humans,” Professor Steffen said.

“… Sitting on our hands means we are at risk of driving the Earth – and human wellbeing – beyond an irreversible point of no return.”

The study, titled Trajectories of the Earth System in the Anthropocene, says temperatures could hit the level needed to send the planet down the “Hothouse Earth” path in just a few decades.

“The impacts of a Hothouse Earth pathway on human societies would likely be massive, sometimes abrupt, and undoubtedly disruptive,” says the study, which is published in the journal Proceedings of the National Academy of Sciences of the United States of America.

Professor Steffen said scientists considered 10 natural feedback processes as part of the study, some of which were “tipping elements” that could lead to abrupt changes if a critical threshold was crossed.

Those elements included the reduction of Antarctic sea ice and polar sheets, the release of methane trapped on the ocean floor and Amazon rainforest dieback.

“The real concern is these tipping elements can act like a row of dominoes,” Professor Steffen said.

“Once one is pushed over, it pushes Earth towards another.

“It may be very difficult or impossible to stop the whole row of dominoes from tumbling over.”

The impacts on arguably Australia’s most notable natural attraction, the Great Barrier Reef, would be severe.

“A Hothouse Earth trajectory would almost certainly flood deltaic environments, increase the risk of damage from coastal storms, and eliminate coral reefs … by the end of this century or earlier,” the study says.

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Climate change: ‘Hothouse Earth’ risks even if CO2 emissions slashed #auspol #qldpol #StopAdani #NoNewCoal @SciNate

By Matt McGrath BBC Environment correspondent

Getty Images

It may sound like the title of a low budget sci-fi movie, but for planetary scientists, “Hothouse Earth” is a deadly serious concept.

Researchers believe we could soon cross a threshold leading to boiling hot temperatures and towering seas in the centuries to come.

Even if countries succeed in meeting their CO2 targets, we could still lurch on to this “irreversible pathway”.

Their study shows it could happen if global temperatures rise by 2C.

An international team of climate researchers, writing in the journal, Proceedings of the National Academy of Sciences, says the warming expected in the next few decades could turn some of the Earth’s natural forces – that currently protect us – into our enemies.

Human actions boosted heatwave odds

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Young will pick up ‘climate change bill’

Each year the Earth’s forests, oceans and land soak up about 4.5 billion tonnes of carbon that would otherwise end up in our atmosphere adding to temperatures.

Getty Images

Many parts of the world would be significantly disrupted in a Hothouse Earth scenario

But as the world experiences warming, these carbon sinks could become sources of carbon and make the problems of climate change significantly worse.

So whether it is the permafrost in northern latitudes that now holds millions of tonnes of warming gases, or the Amazon rainforest, the fear is that the closer we get to 2 degrees of warming above pre-industrial levels, the greater the chances that these natural allies will spew out more carbon than they currently now take in.

Back in 2015, governments of the world committed themselves to keeping temperature rises well below 2 degrees, and to strive to keep them under 1.5. According to the authors, the current plans to cut carbon may not be enough if their analysis is correct.

“What we are saying is that when we reach 2 degrees of warming, we may be at a point where we hand over the control mechanism to Planet Earth herself,” co-author Prof Johan Rockström, from the Stockholm Resilience Centre, told BBC News.

“We are the ones in control right now, but once we go past 2 degrees, we see that the Earth system tips over from being a friend to a foe. We totally hand over our fate to an Earth system that starts rolling out of equilibrium.”

Getty Images

Melting ice in the Arctic will reduce the amount of sunlight reflected back into space

Currently, global temperatures have risen about 1 degree above pre-industrial levels and they are rising by around 0.17C per decade.

In their new study the authors looked at 10 natural systems, which they term “feedback processes”.

Right now, these help humanity to avoid the worst impacts of carbon and temperature rises, and include forests, Arctic sea-ice, and methane hydrates on the ocean floor.

The worry is that if one of these systems tips over and starts pushing large amounts of CO2 into the atmosphere, the rest could follow like a row of dominoes.

What exactly is a Hothouse Earth scenario?

In short, it’s not good.

Getty Images

Flooding and coastal erosion may be a major problem in a warmer world

According to the research paper, crossing into a Hothouse Earth period would see a higher global temperature than at any time in the past 1.2 million years.

The climate might stabilise with 4-5 degrees C of warming above the pre-industrial age. Thanks to the melting of ice sheets, the seas could be 10-60 metres higher than now.

Essentially, this would mean that some parts of the Earth would become uninhabitable.

The impacts would be “massive, sometimes abrupt and undoubtedly disruptive,” say the authors.

The only upside, if you can call it that, is that the worst impacts may not be felt for a century or two. The downside is that we wouldn’t really be able to do anything about it, once it starts.

Are the current heatwaves in the UK and Europe evidence of a Hothouse Earth?

The authors say the extreme weather events we are seeing right now around the world cannot be immediately associated with the risk of passing 2 degrees C.

However, they argue that it may be evidence that the Earth is more sensitive to warming than previously thought.

“One should learn from these extreme events and take these as a piece of evidence that we should be even more cautious,” said Prof Rockström.

“It may support the conclusion that if this can happen at one degree, then we should at least not be surprised or too dismissive of conclusions that things can happen more abruptly than we previously thought.”

Surely we’ve known about these risks before?

What these authors are saying is that up to now, we’ve underestimated the power and sensitivity of natural systems.

People have been thinking that climate change would be a global emergency for everyone if temperatures rose 3-4 degrees by the end of this century.

But this paper argues that beyond 2 degrees, there is a significant risk of turning natural systems – that presently help keep temperatures down – into massive sources of carbon that would put us on an “irreversible pathway” to a world that is 4-5 degrees warmer than before the industrial revolution.

Any good news here at all?

Surprisingly, yes!

We can avoid the hothouse scenario but it’s going to take a fundamental re-adjustment of our relationship with the planet.

“Climate and other global changes show us that we humans are impacting the Earth system at the global level. This means that we as a global community can also manage our relationship with the system to influence future planetary conditions.

“This study identifies some of the levers that can be used to do so,” says co-author Katherine Richardson from the University of Copenhagen.

So not only are we going to have to stop burning fossil fuels by the middle of this century, we are going to have to get very busy with planting trees, protecting forests, working out how to block the Sun’s rays and developing machines to suck carbon out of the air.

Carbon Engineering

Removing carbon dioxide from the atmosphere, as in this model, will be necessary, say the authors

The authors say a total re-orientation of human values, equity, behaviour and technologies is required. We must all become stewards of the Earth.

What do other scientists say?

Some say the authors of this paper are too extreme. Many others say their conclusions are sound.

“As a result of human impacts on climate, the new paper argues that we’ve gone beyond any chance of the Earth cooling ‘of its own accord’,” said Dr Phil Williamson from the University of East Anglia, UK.

“Together these effects could add an extra half a degree Celsius by the end of the century to the warming that we are directly responsible for ‒ thereby crossing thresholds and tipping points that seem likely to occur around 2 degrees C, and committing the planet to irreversible further change, as Hothouse Earth.”

Others are concerned that the authors’ faith in humanity to grasp the serious nature of the problem is misplaced.

“Given the evidence of human history, this would seem a naive hope,” said Prof Chris Rapley, from University College London.

“At a time of the widespread rise of right-wing populism, with its associated rejection of the messages of those perceived as ‘cosmopolitan elites’ and specific denial of climate change as an issue, the likelihood that the combination of factors necessary to allow humanity to navigate the planet to an acceptable ‘intermediate state’ must surely be close to zero.”

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Our climate plans are in pieces as killer summer shreds records #auspol #qldpol #nswpol #StopAdani #NoNewCoal #ClimateChange

(CNN) — Deadly fires have scorched swaths of the Northern Hemisphere this summer, from California to Arctic Sweden and down to Greece on the sunny Mediterranean. Drought in Europe has turned verdant land barren, while people in Japan and Korea are dying from record-breaking heat.

Climate change is here and is affecting the entire globe — not just the polar bears or tiny islands vulnerable to rising sea levels — scientists say. It is on the doorsteps of everyday Americans, Europeans and Asians, and the best evidence shows it will get much worse.

This summer, 119 people in Japan died in a heat wave, while 29 were killed in South Korea, officials there say. Ninety-one people in Greece died in wildfires, and ongoing fires in California have taken at least eight lives. Spain and Portugal sweltered through an exceptionally hot weekend with a heat wave that has killed three people in Spain and pushed temperatures toward record levels..

View this interactive content on CNN.com

Deadly heat waves will become more frequent and occur in more places on the planet in coming decades, according to a study published last summer in the journal Nature Climate Change. Extreme heat waves are frequently cited as one of the most direct effects of man-made climate change.

Remarkably, scientists can now work out in just a matter of days how much human-induced climate change has had to do with a particular weather event, using a combination of observation, historical data and current information from weather stations.

2018 is on pace to be the 4th-hottest year on record

“The European heat wave was at least twice as likely to happen because of human intervention. Based on findings in Ireland it was double — and we know that with very high confidence — and based on data from all other weather stations it was more than double,” said Karsten Haustein from the World Weather Attribution Project, part of Oxford University’s Environmental Change Institute.

Scientists have been able to use this kind of modeling for more than a decade, but improved technology now allows them to do it nearly in real time, letting people understand the links between what they are seeing and climate change.

Despite the deadly summer, overwhelming evidence that humans are altering the planet, and ever-improving science that links specific weather events to global warming, the international politics around the issue of climate change are in disarray. And there are alarming signs that the planet may be in worse shape than ever before.

A house is caught up in the Carr fire in Redding, California, on July 27.

Carbon levels highest in 800,000 years

A report released Wednesday by the US National Oceanic and Atmospheric Administration (NOAA) gave the Earth in 2017 a grim report card.

The major greenhouse gases — carbon dioxide, methane and nitrous oxide — all rose to record levels last year. The global average carbon dioxide concentration was the highest ever recorded, and higher than at any point in the past 800,000 years, according to ice-core data.

Grim report card for planet ranks 2017 one of hottest years in recorded history

Spending on oil and gas increased last year, pushing up the share of fossil fuels in energy supply investment for the first time since 2014, according to the International Energy Agency. Investment in renewable energy dropped 7%, while demand for coal rose, largely to keep Asia’s furnaces burning as the region rapidly develops.

And last year also saw US President Donald Trump announce his plan to pull the US from the Paris Agreement, in a striking blow to global action on climate change. The US is the world’s second-biggest emitter of carbon dioxide, and a pact without the powerhouse nation is significantly weakened.

The symptoms of climate change were also dramatic. Last year was the second or third-hottest year on record, depending on the dataset used, following three record-breaking hot years, the NOAA report showed. It was the hottest year on record without an El Niño, the natural weather event that adds to the warming of the seas and the whole planet.

A new record for global sea levels was set. Unprecedented coral bleaching occurred, and both the Arctic and the Antarctic saw record-low levels of sea ice, as warmer air and seas continued the trend of thinning out the polar ice.

Most Americans accept man-made climate change is real

The Earth has been getting steadily warmer since humans began using high levels of fossil fuels in the 18th to 19th centuries, during the Industrial Revolution. The planet has already warmed by around 1 degree Celsius since the late 19th century.

View this interactive content on CNN.com

More and more Americans are starting to accept climate change is happening, despite Trump’s pledge to pull the US from the Paris Agreement.

American acceptance of climate change returned to an all-time high of 71% in October last year after sliding significantly from around a decade ago, according to the Yale Program on Climate Change Communication, which conducts quarterly surveys on attitudes to global warming. It has dropped to 70% this year so far.

Some 58% of Americans believe that climate change is mostly man-made, a clear majority but a lower percentage than in most other developed nations.

This understanding that climate change is at least happening has a lot to do with what people are seeing and experiencing, according to the Yale program’s director, Anthony Leiserowitz.

After the US was hit with several catastrophic hurricanes, the number of people who felt global warming was affecting US weather “a lot” leaped to 33% last October from 25% in May, five months earlier. That number went back down when winter came and extreme weather events subsided.

People walk through flooded roads in Houston, Texas, on August 27, 2017 as Hurricane Harvey hit the city.

“People are increasingly connecting the dots when they see these weather events happening across the United States,” Leiserowitz said.

“It’s about the pattern — if an extreme event happens once or twice, it’s just a coincidence, but three, five, 12, 22 times, seeing record-setting events, seeing 1,000-year event after 1,000-year event happen frequently, people begin to see that larger pattern, that climate change is actually affecting the weather today. And that’s a new concept for many Americans.”

This increase in awareness appears to be happening in Redding, California. The Carr Fire has torched more than 130,000 acres of land — the equivalent of nearly 100,000 football fields — and it became so big and hot this week, it created its own weather system.

Firefighter Gabriel Lauderdale, 29, has lived all his life by the forest near Redding, and he says even that’s enough time to have noticed the pattern and behavior of wildfires change dramatically.

“There seems to be more destructive wildfires and they’re happening more frequently,” said Lauderdale.

“It used to be that a 10,000-acre fire was a large fire, and in these cases, we’re seeing many exceed 100,000 acres, and they reach that size relative quickly. They move into homes and businesses, and they move very fast from structure to structure.”

The US pulls the plug on Paris

The Paris Agreement in 2015 was widely celebrated as an achievement, but it has major flaws — it is not legally binding, it’s unenforceable and soon it is likely to lack one of the world’s biggest polluters.

The agreement’s predecessor, the Kyoto Protocol, was much stronger. It set ambitious and legally binding emissions reduction targets. But it too had its problems.

It included only developed nations, so China, the world’s biggest carbon emitter, was not obliged to make reductions.

View this interactive content on CNN.com

This was always a sticking point for the US. George W. Bush in 2001 pulled his country out of the Kyoto agreement, which Congress had never ratified.

Kyoto’s other major flaw was that although it was legally binding, no one was ever sanctioned for over-polluting.

So the success of Paris lies in the fact that it at least engaged more than just developed nations. Those who ratify it make pledges to combat climate change as their countries see fit, and they are obliged to report on them transparently, in more of a name-and-shame system than one with mutually set goals.

Another success of Paris is the recognition that the world should try to contain warming to 1.5 degrees Celsius above pre-industrial levels, or two degrees as a worst-case scenario.

The agreement, however, did not include the legally binding goals to reduce carbon emissions that were sought by Europe but largely opposed by the US.

Cars are blocked after a wildfire caused a road closure in Kineta in Greece on July 23.

Now the world is left with a watered-down agreement, and the country that pushed strongly for that dilution is no longer playing along.

Todd Stern, the chief US negotiator in Paris, and the Obama administration are credited with bringing the US back into the fold after pulling out of Kyoto. But, Stern said, they knew they would never get binding targets past Congress, so they went into talks seeking an agreement that wouldn’t need Congressional approval.

Stern denies, however, that the US was the only one against binding targets, saying he would be “stunned” if all countries had agreed to get on board.

He made clear his strong disapproval of Trump’s announcement the day after it happened, and he has written op-ed after op-ed warning of the dangers of doing so.

“It’s a completely mind-bogglingly, ill-informed and unwise decision for so many reasons,” Stern told CNN, adding that the US was “too big and influential” to be left out.

Trump has governed with his “America First” agenda at the forefront of his policy making and had argued that the Paris Agreement placed “draconian” financial burdens on the American people.

“I was elected by the citizens of Pittsburgh, not Paris,” he said upon making his announcement in June last year.

With the Paris Agreement being largely non-binding and with the US out of the deal, environmental groups are calling on the rest of the world to make stronger commitments.

“All other nations have to ditch incremental action for transformational change,” said Claire Norman, speaking for Friends of the Earth in the UK.

“Other nations will need to step up — especially the UK, we used to be world-leading — and use every diplomatic and economic tool to compel the US to act.”

CNN’s Brandon Miller, Judson Jones, John Sutter, Laura Smith-Spark and Mark Oliver contributed to this report.

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#ClimateChange isn’t a debate. #auspol #qldpol #nswpol #QandA @SciNate #Drought #Heatwave #StopAdani #NoNewCoal

Global heatwave: Climate change is no longer a two-way debate – Dr Peter Stott

The pattern of heatwaves causing record breaking temperatures across the northern hemisphere would not be seen without climate change, and they have firmly focused the conversation on what we can do about it rather than whether it’s happening, according to Peter Stott, professor of detection and attribution of climate change at the University of Exeter, UK.

A study of this summer’s heatwave says that it was two times more likely to happen than if human activities hadn’t changed the climate.

So, can we say that climate change has caused the heatwave?

‘If you talk about any one event, you can’t necessarily say that it is unequivocally caused by climate change because such a situation could have happened without climate change.

We know there have been extreme weather events in the past, we know there have been heatwaves in the past, but what we’ve seen very clearly from the observational information (is that) the frequency of heatwaves around the world has increased significantly.

What we can do then is talk about the odds of a particular heatwave happening in a particular locality, and then you can talk about how the odds are changing.’

Why is it so hard to know for sure?

‘The attribution problem is trying to detect the signal of human-induced climate change over the noise of natural variations of the climate.

In terms of global temperatures, the global picture is very clearly, “Yes we can.” When we come to extreme weather events, such as this heatwave, the challenge is to figure out how has global warming changed the odds for such a heatwave.

‘The way we do that is we compare the world we live in, which has factors like raised greenhouse gas concentrations, variations of solar and volcanic activity, and the El Niño fluctuations.

You can then calculate what the odds of a heatwave in that situation are and compare that with a situation when human activity is not present.

The climate still varies by itself, but you don’t have elevated levels of greenhouse gas concentrations and by comparing the two you can work out how much more likely a heatwave has become.’

What are the signs that the heatwaves are not just part of a particularly hot year?

‘Those people who were around in 1976 may remember the heatwave then.

It turns out that the weather patterns that caused that were in some ways rather similar to this year.

What is very different is the fact that in 1976 the heatwave area centred around the UK and North West Europe was fairly isolated, with patches of high temperatures.

This year we are seeing heatwaves in Japan, in Northern Scandinavia, and in parts of the USA, right now the temperatures are building in southern Europe too. It is a big hemispheric pattern of elevated temperatures in the northern hemisphere and that is something that we wouldn’t see without climate change.’

Are these heatwaves a sign that we have passed a tipping point and global heatwaves are here to stay?

‘There is a lot of doom and gloom about climate change, but a lot of that is linked to what would happen if we continue to emit greenhouse gas emissions.

That trajectory of having many more extreme weather events in Europe in 30 years’ time is only going to happen if we continue to emit greenhouse gases.

If we succeed in reaching the Paris goal that the governments have signed up to then the world would look like a very different place.

It is a world where we can minimise the risks of the extreme weather events or ice sheets collapsing, it’s a world where we can feed the world’s population.’

You coordinate a transnational project called EUPHEME, which examines the risks of extreme weather and climate events.

How do you hope this research will help fight climate change?

‘One of the crucial aspects we need is to learn from what has been happening, from the impacts.

We’ve seen it in the fires in Greece, the extreme heatwave in Japan where quite a number of people died, we can see the impact on agriculture directly. What we are doing with EUPHEME is linking that back to climate change.

That is allowing us to understand where there are risks.

If you think about food security, for example, EUPHEME is helping us understand where the risk of food security and climate change lie.

‘It is also about refining the (climate) models and refining our understanding of those models so we can be increasingly confident about our results and that they are trustworthy for a variety of users.

Different users will have different uses for that information. A key aspect is how we communicate these results in ways that are best served to different stakeholders, whether that is policymaking, journalists or members of the public or people in the insurance industry.’

‘That trajectory of having many more extreme weather events in Europe in 30 years’ time is only going to happen if we continue to emit greenhouse gases.’

Peter Stott, University of Exeter, UK

Are you only looking at heatwaves?

Heatwaves are not straightforward (to attribute to climate change), but they are easier to do because they are large scale and over a long period of time, while a wind storm or flash flood are very localised and occur (over) just a few hours.

At the moment, when certain extreme weather events happen you might hear from the attribution community saying we can’t really say that about that situation because the climate models aren’t capable of simulating it well or we don’t have all the information.

We want to try to develop the capability to look at those events as well, because we recognise that people are asking the exactly same questions about wind storms and flash floods then they are about the large-scale heatwave.’

Do you think these heatwaves will prove to be a wake-up call for the world to take more climate action?

‘A few years ago, the UK tabloids (newspapers) would put up a climate sceptic against a scientist and have a two-way debate, there has been almost none of that this time.

It is much more about what is this link between this heatwave and climate change and what this means for the future.

‘Now some of the UK tabloids have been leading on climate change, which has changed from a few years ago – they are not attacking climate scientists or the idea of climate change anymore.

They are reporting on scientists saying that there is a link to climate change here.

There is a sense that it has become mainstream that climate change is happening and has affected this particular heatwave.

Not to everybody of course, but there is a wider acceptance because people are starting to say they can see it with their own eyes which is a crucial part of dealing with climate change.’

Press link for more

Horizon

Scientists Have Uncovered a Disturbing #ClimateChange Precedent #auspol #qldpol #nswpol #StopAdani @SciNate #Drought #Heatwave

During the rise of mammals, Earth’s temperatures spiked in a scary way that the planet may experience again soon.

Peter Brannen

Mike Hutchings / Reuters

They were strange days at the beginning of the age of mammals.

The planet was still hungover from the astonishing disappearance of its marquee superstars, the dinosaurs.

Earth’s newest crater was still a smoldering system of hydrothermal vents, roiling under the Gulf of Mexico.

In the wake of Armageddon our shell-shocked ancestors meekly negotiated new roles on a planet they inherited quite by accident. Before long, life settled into new rhythms: Earth hosted 50-foot-long boas sliding through steam-bath jungles, birds grew gigantic in imitation of their dearly departed cousins, and mildly modern mammals we might squint to recognize appeared.

Within a few million years, loosed from under the iron heel of the vanished giants, they began to experiment.

Early whales pranced across a Pakistani archipelago on all fours, testing out life in the water. The first lemur-like primates leapt from the treetops, and hoofed things of all varieties dashed through the forest.

But the most striking feature of this early age of mammals is that it was almost unbelievably hot, so hot that around 50 million years ago there were crocodiles, palm trees, and sand tiger sharks in the Arctic Circle.

On the other side of the blue-green orb, in waters that today would surround Antarctica, sea-surface temperatures might have topped an unthinkable 86 degrees Fahrenheit, with near-tropical forests on Antarctica itself.

There were perhaps even sprawling, febrile dead zones spanning the tropics, too hot even for animal or plant life of any sort.

This is what you get in an ancient atmosphere with around 1,000 parts per million (ppm) of carbon dioxide.

If this number sounds familiar, 1,000 ppm of CO2 is around what humanity is on pace to reach by the end of this century.

That should be mildly concerning.

“You put more CO2 in the atmosphere and you get more warming, that’s just super-simple physics that we figured out in the 19th century,” says David Naafs, an organic geochemist at the University of Bristol. “But exactly how much it will warm by the end of the century, we don’t know.

Based on our research of these ancient climates, though, it’s probably more than we thought.”

Last week, Naafs and colleagues released a study in Nature Geoscience that reconstructs temperatures on land during this ancient high-CO2 hothouse of the late Paleocene and early Eocene epochs—the sweltering launch to the age of mammals. And the temperatures they unearthed are unsurprisingly scorching.

To study Earth’s past, scientists need good rocks to study, and fortunately for geologists and fossil-fuel companies alike, the jungles and swamps of this early age of mammals left behind lots of coal.

The Powder River Basin in the United States, for instance, is filled with fossil Paleocene swamplands that, when burned today, contribute about 10 percent of U.S. carbon emissions.

Naafs’ team studied examples of lower-quality coals called lignites, or fossilized peat. They had been collected around the world (everywhere from open-pit coal mines in Germany to outcrops in New Zealand), and spanned the late-Paleocene and early-Eocene epochs, from around 56 to 48 million years ago.

They were able to reverse engineer the ancient climate by analyzing temperature-sensitive structures of lipids produced by fossil bacteria and archaea living in these bygone wetlands, and preserved for all time in the coal.

The team found that, under this past regime of high CO2, in the ancient U.K., Germany, and New Zealand, life endured mean annual temperatures of 23–29 degrees Celsius (73–84 degrees Fahrenheit) or 10–15 degrees Celsius (18–27 degrees Fahrenheit) warmer than modern times.

“These wetlands looked exactly how only tropical wetlands look at present, like the Everglades or the Amazon,” Naafs says. “So Europe would look like the Everglades and a heat wave like we’re currently experiencing in Europe would be completely normal.

That is, it would be the everyday climate.”

That modern European heat wave has, in recent weeks, sent sunbathing Scandinavians and reindeer to the beach in temperatures topping 90 degrees Fahrenheit in the Arctic Circle.

It has also ignited devastating wildfires across Greece and triggered an excruciating weekend for Spain and Portugal. But over 50 million years ago this would have been the baseline from about 45 to 60 degrees latitude.

Under this broiling regime, with unprecedented heat as the norm, actual heat waves might have begun to take on an unearthly quality.

“Perhaps a heat wave in Europe would be something like 40 degrees Celsius (104 degrees Fahrenheit) for three weeks.

We don’t know.” So that was life in the late Paleocene and early Eocene in the high mid-latitudes. But closer to the equator in this global sweat lodge, the heat might have been even more outrageous, shattering the limits of complex life.

To see exactly how hot, Naafs’ team also analyzed ancient lignite samples from India, which would have been in the tropics at the time—that subcontinent still drifting across the Indian Ocean toward its eventual mountain-raising rendezvous with Asia. But unfortunately, the temperatures from these samples were maxed out.

That is, they were too hot for his team to measure by the new methods they had developed.

So it remains an open question just how infernal the tropics became in these early days of our ancestors, but some computers tasked with recreating this planet spit out the stuff of science fiction.

“Some climate models suggest that the tropics just became a dead zone with temperatures over 50 degrees Celsius (122 degrees Fahrenheit) like in Africa and South America,” says Naafs. “But we have no data so we don’t know.”

Naafs’ work fits into a larger developing picture of Earth as an almost unrecognizable greenhouse planet of the distant past.

University of Colorado paleontologist Jaelyn Eberle recently returned to her office in Boulder from Ellesmere Island, in the Canadian High Arctic, where she’s been doing research since the 1990s.

Ellesmere is as far north as you can get before you fall off North America and run into Père Noël drifting over pack ice. Here, featureless highlands overlook ice-choked fjords and a lone Peary’s caribou might mingle with a dozen musk oxen under a vast Nunavut sky. There are also polar bears, but Eberle luckily hasn’t had any run-ins so far—though perspective can play tricks on you at the top of the world, and a snow-white artic hare on its hind legs at the appropriate distance can appear threatening enough.

“You pick up your gun and get all nervous and worried and then look through your binoculars … It’s just a rabbit,” says Eberle.

But Eberle isn’t venturing this far north just for the occasional hair-raising encounter with polar wildlife. Her target is warmer-weather fauna. Though there are no trees here at the top of the world, there are tree stumps. And they are around 50 million years old.

“The fossil forests on Ellesmere are spectacular,” Eberle says about the ecosystem entombed in the arctic soils. “You start really looking into them and you go, ‘Wow. We are dealing with a rainforest.’”

Eberle is a vertebrate paleontologist and though there’s the aforementioned odd musk ox passing by her camp to consider, in the rocks below she has her pick of animals to study.

“You’ve got alligators, giant tortoises, primates, things like that.

We have these big hippo-like animals called Coryphodon.

You have tapirs—so you’ve got tapirs living pretty close to the North Pole in the early Eocene, which today—clearly tapirs are not at the North Pole,” she says, laughing.

The presence of these animals suggests a very warm world indeed. And yet, there is a seeming disconnect, between traditional projections for future warming—like those made by the International Panel on Climate Change (IPCC), which predicts around 4 degrees Celsius (7 degrees Fahrenheit) of warming by the end of the century under a business-as-usual emissions scenario (still frightening) and sea-level rise measured in mere inches (still frightening)—and the scarcely recognizable Earths buried in the rocks and created under similar CO2 regimes, like those that Eberle unearths.

One obvious way to reconcile this disparity is by noticing that the changes to the ancient earth took place over hundreds-of-thousands to millions of years and (IPCC graphs notwithstanding) that time won’t stop at the end of the 21st century.

The changes that we’ve already set in motion, unless we act rapidly to countervail them, will similarly take millennia to fully unfold.

The last time CO2 was at 400 ppm (as it is today) was 3 million years ago during the Pliocene epoch, when sea levels were perhaps 80 feet higher than today.

Clearly the climate is not yet at equilibrium for a 400-ppm world.

And it won’t be for quite some time.

And anyway, we’re clearly not content to stop at just 400 ppm.

If we do, in fact, push CO2 up to around 1,000 ppm by the end of the century, the warming will persist and the earth will continue to change for what, to humans, is a practical eternity. And when the earth system finally does arrive at its equilibrium, it will most likely be in a climate state with no analog in the short evolutionary history of Homo sapiens.

Most worryingly, the climate models that we depend on as a species to predict our future have largely failed to predict our sultry ancient past. And though the gulf is narrowing, and models are catching up, even those that come close to reproducing the hothouse of the early Eocene require injecting 16 times the modern level of CO2 into the air to achieve it—far beyond the rather meager doubling or tripling of CO2 indicated by the rock record.

Clearly we are missing something, and Naafs thinks that one of the missing ingredients in the models is methane, a powerful greenhouse gas which might help close the divide between model worlds and fossil worlds.

“We know nothing about the methane cycle during these greenhouse periods,” he says. “We know the hotter it gets the more methane comes out of these wetlands, but we know nothing about the methane cycle beyond the reach of ice cores which only goes back 800,000 years … We know tropical wetlands pump much more methane into the atmosphere compared to [cooler] wetlands. And we know methane can actually amplify high-latitude warming, so maybe that’s some of the missing feedback.”

In many ways these ancient worlds are not analogs to our own. We have to be careful when making comparisons between the two. The early age of mammals was a different world. The continents were in slightly different positions, leading to a vastly different ocean circulation and boundary conditions quite unlike our own world, 50 million years on—with all the tectonic, oceanographic, and biological changes that come with such a yawning expanse of time. But artificially jam enough greenhouse gases into the atmosphere and Naafs thinks that many of the wildest features of the early age of mammals could be recreated.

“If we were to burn all the fossil fuels and wait a few centuries we might return to this,” he says. “Basically every type of paleoclimate research that’s being done shows that high CO2 means that it’s very warm. And when it gets very warm, it can be really, really, really warm.”

Press Link for more: The Atlantic

Scientists Have Uncovered a Disturbing #ClimateChange Precedent #auspol #qldpol #nswpol #StopAdani @SciNate #Drought #Heatwave

During the rise of mammals, Earth’s temperatures spiked in a scary way that the planet may experience again soon.

Peter Brannen

Mike Hutchings / Reuters

They were strange days at the beginning of the age of mammals.

The planet was still hungover from the astonishing disappearance of its marquee superstars, the dinosaurs.

Earth’s newest crater was still a smoldering system of hydrothermal vents, roiling under the Gulf of Mexico.

In the wake of Armageddon our shell-shocked ancestors meekly negotiated new roles on a planet they inherited quite by accident. Before long, life settled into new rhythms: Earth hosted 50-foot-long boas sliding through steam-bath jungles, birds grew gigantic in imitation of their dearly departed cousins, and mildly modern mammals we might squint to recognize appeared.

Within a few million years, loosed from under the iron heel of the vanished giants, they began to experiment.

Early whales pranced across a Pakistani archipelago on all fours, testing out life in the water. The first lemur-like primates leapt from the treetops, and hoofed things of all varieties dashed through the forest.

But the most striking feature of this early age of mammals is that it was almost unbelievably hot, so hot that around 50 million years ago there were crocodiles, palm trees, and sand tiger sharks in the Arctic Circle.

On the other side of the blue-green orb, in waters that today would surround Antarctica, sea-surface temperatures might have topped an unthinkable 86 degrees Fahrenheit, with near-tropical forests on Antarctica itself.

There were perhaps even sprawling, febrile dead zones spanning the tropics, too hot even for animal or plant life of any sort.

This is what you get in an ancient atmosphere with around 1,000 parts per million (ppm) of carbon dioxide.

If this number sounds familiar, 1,000 ppm of CO2 is around what humanity is on pace to reach by the end of this century.

That should be mildly concerning.

“You put more CO2 in the atmosphere and you get more warming, that’s just super-simple physics that we figured out in the 19th century,” says David Naafs, an organic geochemist at the University of Bristol. “But exactly how much it will warm by the end of the century, we don’t know.

Based on our research of these ancient climates, though, it’s probably more than we thought.”

Last week, Naafs and colleagues released a study in Nature Geoscience that reconstructs temperatures on land during this ancient high-CO2 hothouse of the late Paleocene and early Eocene epochs—the sweltering launch to the age of mammals. And the temperatures they unearthed are unsurprisingly scorching.

To study Earth’s past, scientists need good rocks to study, and fortunately for geologists and fossil-fuel companies alike, the jungles and swamps of this early age of mammals left behind lots of coal.

The Powder River Basin in the United States, for instance, is filled with fossil Paleocene swamplands that, when burned today, contribute about 10 percent of U.S. carbon emissions.

Naafs’ team studied examples of lower-quality coals called lignites, or fossilized peat. They had been collected around the world (everywhere from open-pit coal mines in Germany to outcrops in New Zealand), and spanned the late-Paleocene and early-Eocene epochs, from around 56 to 48 million years ago.

They were able to reverse engineer the ancient climate by analyzing temperature-sensitive structures of lipids produced by fossil bacteria and archaea living in these bygone wetlands, and preserved for all time in the coal.

The team found that, under this past regime of high CO2, in the ancient U.K., Germany, and New Zealand, life endured mean annual temperatures of 23–29 degrees Celsius (73–84 degrees Fahrenheit) or 10–15 degrees Celsius (18–27 degrees Fahrenheit) warmer than modern times.

“These wetlands looked exactly how only tropical wetlands look at present, like the Everglades or the Amazon,” Naafs says. “So Europe would look like the Everglades and a heat wave like we’re currently experiencing in Europe would be completely normal.

That is, it would be the everyday climate.”

That modern European heat wave has, in recent weeks, sent sunbathing Scandinavians and reindeer to the beach in temperatures topping 90 degrees Fahrenheit in the Arctic Circle.

It has also ignited devastating wildfires across Greece and triggered an excruciating weekend for Spain and Portugal. But over 50 million years ago this would have been the baseline from about 45 to 60 degrees latitude.

Under this broiling regime, with unprecedented heat as the norm, actual heat waves might have begun to take on an unearthly quality.

“Perhaps a heat wave in Europe would be something like 40 degrees Celsius (104 degrees Fahrenheit) for three weeks.

We don’t know.” So that was life in the late Paleocene and early Eocene in the high mid-latitudes. But closer to the equator in this global sweat lodge, the heat might have been even more outrageous, shattering the limits of complex life.

To see exactly how hot, Naafs’ team also analyzed ancient lignite samples from India, which would have been in the tropics at the time—that subcontinent still drifting across the Indian Ocean toward its eventual mountain-raising rendezvous with Asia. But unfortunately, the temperatures from these samples were maxed out.

That is, they were too hot for his team to measure by the new methods they had developed.

So it remains an open question just how infernal the tropics became in these early days of our ancestors, but some computers tasked with recreating this planet spit out the stuff of science fiction.

“Some climate models suggest that the tropics just became a dead zone with temperatures over 50 degrees Celsius (122 degrees Fahrenheit) like in Africa and South America,” says Naafs. “But we have no data so we don’t know.”

Naafs’ work fits into a larger developing picture of Earth as an almost unrecognizable greenhouse planet of the distant past.

University of Colorado paleontologist Jaelyn Eberle recently returned to her office in Boulder from Ellesmere Island, in the Canadian High Arctic, where she’s been doing research since the 1990s.

Ellesmere is as far north as you can get before you fall off North America and run into Père Noël drifting over pack ice. Here, featureless highlands overlook ice-choked fjords and a lone Peary’s caribou might mingle with a dozen musk oxen under a vast Nunavut sky. There are also polar bears, but Eberle luckily hasn’t had any run-ins so far—though perspective can play tricks on you at the top of the world, and a snow-white artic hare on its hind legs at the appropriate distance can appear threatening enough.

“You pick up your gun and get all nervous and worried and then look through your binoculars … It’s just a rabbit,” says Eberle.

But Eberle isn’t venturing this far north just for the occasional hair-raising encounter with polar wildlife. Her target is warmer-weather fauna. Though there are no trees here at the top of the world, there are tree stumps. And they are around 50 million years old.

“The fossil forests on Ellesmere are spectacular,” Eberle says about the ecosystem entombed in the arctic soils. “You start really looking into them and you go, ‘Wow. We are dealing with a rainforest.’”

Eberle is a vertebrate paleontologist and though there’s the aforementioned odd musk ox passing by her camp to consider, in the rocks below she has her pick of animals to study.

“You’ve got alligators, giant tortoises, primates, things like that.

We have these big hippo-like animals called Coryphodon.

You have tapirs—so you’ve got tapirs living pretty close to the North Pole in the early Eocene, which today—clearly tapirs are not at the North Pole,” she says, laughing.

The presence of these animals suggests a very warm world indeed. And yet, there is a seeming disconnect, between traditional projections for future warming—like those made by the International Panel on Climate Change (IPCC), which predicts around 4 degrees Celsius (7 degrees Fahrenheit) of warming by the end of the century under a business-as-usual emissions scenario (still frightening) and sea-level rise measured in mere inches (still frightening)—and the scarcely recognizable Earths buried in the rocks and created under similar CO2 regimes, like those that Eberle unearths.

One obvious way to reconcile this disparity is by noticing that the changes to the ancient earth took place over hundreds-of-thousands to millions of years and (IPCC graphs notwithstanding) that time won’t stop at the end of the 21st century.

The changes that we’ve already set in motion, unless we act rapidly to countervail them, will similarly take millennia to fully unfold.

The last time CO2 was at 400 ppm (as it is today) was 3 million years ago during the Pliocene epoch, when sea levels were perhaps 80 feet higher than today.

Clearly the climate is not yet at equilibrium for a 400-ppm world.

And it won’t be for quite some time.

And anyway, we’re clearly not content to stop at just 400 ppm.

If we do, in fact, push CO2 up to around 1,000 ppm by the end of the century, the warming will persist and the earth will continue to change for what, to humans, is a practical eternity. And when the earth system finally does arrive at its equilibrium, it will most likely be in a climate state with no analog in the short evolutionary history of Homo sapiens.

Most worryingly, the climate models that we depend on as a species to predict our future have largely failed to predict our sultry ancient past. And though the gulf is narrowing, and models are catching up, even those that come close to reproducing the hothouse of the early Eocene require injecting 16 times the modern level of CO2 into the air to achieve it—far beyond the rather meager doubling or tripling of CO2 indicated by the rock record.

Clearly we are missing something, and Naafs thinks that one of the missing ingredients in the models is methane, a powerful greenhouse gas which might help close the divide between model worlds and fossil worlds.

“We know nothing about the methane cycle during these greenhouse periods,” he says. “We know the hotter it gets the more methane comes out of these wetlands, but we know nothing about the methane cycle beyond the reach of ice cores which only goes back 800,000 years … We know tropical wetlands pump much more methane into the atmosphere compared to [cooler] wetlands. And we know methane can actually amplify high-latitude warming, so maybe that’s some of the missing feedback.”

In many ways these ancient worlds are not analogs to our own. We have to be careful when making comparisons between the two. The early age of mammals was a different world. The continents were in slightly different positions, leading to a vastly different ocean circulation and boundary conditions quite unlike our own world, 50 million years on—with all the tectonic, oceanographic, and biological changes that come with such a yawning expanse of time. But artificially jam enough greenhouse gases into the atmosphere and Naafs thinks that many of the wildest features of the early age of mammals could be recreated.

“If we were to burn all the fossil fuels and wait a few centuries we might return to this,” he says. “Basically every type of paleoclimate research that’s being done shows that high CO2 means that it’s very warm. And when it gets very warm, it can be really, really, really warm.”

Press Link for more: The Atlantic

Earth at risk of ‘hothouse climate’ where efforts to reduce emissions will have no impact! #StopAdani #NoNewCoal #ClimateChange #Drought @SciNate

By Elise Pianegonda

Photo: A “hothouse” climate could trigger earth processes like a major reduction of Antarctic sea ice. (Australian Antarctic Division: Richard Youd)

Related Story: Turnbull defends surprise $444 million Government donation to tiny reef body

Related Story: Lost at sea: the race against time to save the Carteret Islands from climate change

If humans cause the earth’s global average temperature to increase by a further 1 degree Celsius, the world could face a “hothouse” climate and trigger further warming — even when all human emissions cease, an international study has found.

Key points:

• Study found the climate is heading for a tipping point that could make the planet uninhabitable

• It could cause temperatures up to 5C higher than pre-industrial averages

• Current global efforts to curb emissions are “unlikely” to prevent the dangerous situation

The study titled Trajectories of the Earth System in the Anthropocene, which involved researchers from around the world, was published in the international journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).

It found the Earth was heading for a tipping point, known as a “hothouse” climate, which could lead to average temperatures up to 5C higher than pre-industrial temperatures and rises in sea level of between 10 and 60 metres.

Lead researcher Professor Will Steffen from the Australian National University (ANU) said at that point much of the earth would be uninhabitable.

He explained that if human emissions raised global temperatures to 2C above pre-industrial temperatures it could trigger earth system processes — or feedbacks — that could then cause further warming.

“The real concern is these tipping elements can act like a row of dominoes,” Professor Steffen said.

“Once one is pushed over, it pushes earth towards another.

“It may be very difficult or impossible to stop the whole row of dominoes from tumbling over.”

Current efforts ‘unlikely’ to help avoid tipping point

Professor Steffen said global average temperatures were currently just over 1C above pre-industrial temperatures and rising at 0.17C each decade.

Where is the urgency in Australia’s climate policy?

Australia needs to stop pretending we’re tackling climate change.

And he said while humans were not the sole cause of temperature changes on Earth, the current efforts by nations to reduce emissions and stop average temperatures rising by a further 1C were “unlikely to help avoid this very risky situation”.

“Even if the Paris Accord [Agreement] target of a 1.5C to 2C rise in temperature is met, we cannot exclude the risk that a cascade of feedbacks could push the Earth system irreversibly onto a ‘hothouse Earth’ pathway,” the study said.

“As yet [these initiatives] are not enough to meet the Paris target.”

Professor Steffen said countries needed to work together to “greatly accelerate the transition towards an emission-free world economy”.

“If the threshold is crossed, the resulting trajectory would likely cause serious disruptions to ecosystems, society, and economies,” the study said.

“Collective human action is required to steer the Earth system away from a potential threshold and stabilise it in a habitable interglacial-like state.”

The authors of the study examined 10 feedback processes, some of which could cause “the uncontrollable release” of carbon back into the atmosphere, after it had been stored in the earth.

Some of the processes also included permafrost thaw, Amazon rainforest dieback, a reduction of northern hemisphere snow cover, a loss of Arctic summer sea ice, and a reduction of Antarctic sea ice and polar ice sheets.

The study did not lay down a timeframe for when such events would begin to occur, but theorised — if the threshold was crossed — it could be within a century or two.

“The impacts of a hothouse earth pathway on human societies would likely be massive, sometimes abrupt, and undoubtedly disruptive,” the study said.

Press link for more: ABC.NET.AU