11/08/2021

(AU ABC) The IPCC Has Released The Most Comprehensive Climate Change Report Ever. Here's What You Need To Know

ABC News - Michael Slezak | Penny Timms

In Australia, climate change will worsen natural disasters like fires, floods and droughts. (Supplied: Virginia Tapp, File photo)

Worse fires, longer droughts, and more severe floods — the projections from one of the world's most significant reports on climate change make for scary reading. The latest IPCC report says that within a decade, global warming could push temperatures to 1.5 degrees Celsius above pre-industrial levels, and calls on policymakers to take urgent action on climate change.

The report is making headlines around the world, and the United Nations has referred to the situation as a "code red for humanity".

So what are the report's key findings? What is the IPCC? And why is this particular report such a big deal?

Let's break down what it all means.

What does the IPCC report say about how fast we are warming?

 In the 30 years since the first IPCC report was prepared, we've released almost as much greenhouse gas into the atmosphere as humans did throughout our entire history up until 1990.

To be clear, between 1990 and 2021 alone, we released about 41 per cent of all CO2 released since 1750, according to Pep Canadell, head of the Global Carbon Project.

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CO2 levels now are higher than they've been for at least 2 million years.

As a result, warming has accelerated, as have the devastating impacts of extreme weather around the world.

All up, the world has warmed by just under 1.1C, the report concludes. That's compared to the "pre-industrial" baseline, which is treated as the average temperature from 1850 to 1900.

That might not sound like much, but consider this: when the world exited the last ice age, all it took was 5C of warming. And that happened over 5,000 years.

During that period, it took about 1,000 years to warm by 1.5C; now, we're on track to warm 1.5C in about 50 years.

Humans have not existed in a climate like this before, and it's getting worse.

If we reach 2.5C of warming, that will be a temperature the Earth has not sustained for at least 3 million years.

Why would reaching 1.5C by 2030 be a big deal?
Heavy rainfall events that can cause flooding will also get worse as the temperature rises. (Supplied: Northam Police, File photo)

Back in 2015, as part of what's called the Paris Agreement, the world's governments agreed to keep global warming to below 2C this century.

But they agreed that ideally, global warming would be limited to 1.5C — and promised to pursue efforts to do that.

The reason for that particular target is that each incremental bit of warming causes big changes to extreme weather like dangerous floods, heatwaves, cyclones, and droughts. Heating the world to 2C would make life much more difficult for humanity.

Now, the latest IPCC report has found keeping below that threshold of 1.5C is highly unlikely.

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It examines a series of different possible futures, and in all of them, we cross the 1.5C threshold before about 2035, and in the worst scenario by 2028.

In the most ambitious scenario, we rapidly cut emissions today, get to net zero emissions globally by 2050, and then continue to suck CO2 out of the atmosphere.

In that scenario, we reach 1.5C in about 2035 and then dip back down below it again.

Current pledges made by countries, however, get us nowhere near that. Instead, they take us towards about 3C of warming by the end of the century — something that would be disastrous for much of humanity.

What is the IPCC, and why is it important?

It's the Intergovernmental Panel on Climate Change, or IPCC. You may see news stories about climate change fairly often, but the IPCC's work is significant for several reasons.

It was set up by the United Nations in the 1980s, and aims to synthesise all that we currently know about climate change.

To do that, it combines and assesses a massive amount of science — tens of thousands of research papers — and boils it down into something relatively digestible. While its final report will be thousands of pages long, a 40-page "Summary for Policymakers," was released yesterday, and is what most people rely on.

What's important to know is that the key Summary for Policymakers is fundamentally a report by governments. After hundreds of scientists write the report, it's then approved — line-by-line — by 195 governments around the world.

Mark Howden, who is vice chair of the IPCC and a professor at ANU, says that means it's hard for governments to ignore it when they design policy.

"Rather than being external to the governments, it's actually part of their processes," he says.

"And that helps inform those government policies."

What's the latest IPCC report everyone is talking about?

Back in 1990, the IPCC released its First Assessment Report.

The report released yesterday was the first part of the Sixth Assessment Report, the rest of which will come out over the next year.

These reports are the most comprehensive analyses of what is known about the Earth's climate: how it is warming, what the impacts will be and how we can stop it.

The section released yesterday looked at the physical science of climate change.

The next part, coming out soon, looks at the impacts of climate change, and the final instalment looks at how to mitigate those impacts.

What are the other key takeaways from the report?

There is no longer any doubt that humans have changed the climate.

The report says: "It is unequivocal that human influence has warmed the atmosphere, ocean and land. Widespread and rapid changes in the atmosphere, ocean, cryosphere and biosphere have occurred."

Amazingly, another type of human pollution has in fact cooled the Earth a little.

The greenhouse gases we've been emitting into the atmosphere would have warmed the world by 1.5C already, if it weren't for aerosol pollution. Aerosol pollution comes with its own problems — it is thought to contribute to millions of deaths globally each year through lung cancer, heart disease and stroke.

The Greenland and Antarctic ice sheets contain huge amounts of frozen water. (Supplied: British Antarctic Survey, File photo)

The report says many of the changes we've already caused will now persist, or continue to change, for centuries or millennia — particularly oceans, ice sheets and sea level.

When it comes to sea level, the report says that by the end of the century we're likely to see a rise of between 28cm and 55cm.

But because of uncertainties about how ice sheets in Greenland and Antarctica will evolve, it can't rule out a 2-metre sea level rise by the end of the century, and a 5-metre rise 50 years later.

Professor Howden describes the possibility of such sea level rises as "seriously scary".

What does global warming mean for Australia?

In Australia, the impacts we'll see will be an acceleration of those we've already lived through.

Fires will get even worse, they'll happen more often, and the fire seasons will get longer.

Fires are projected to get worse and more frequent due to global warming. (AAP: Dean Lewins, File photo)

Heavy rainfall events that can cause flooding will also get worse, but for many parts of Australia, it will rain less often.

Droughts in the south-west of the country will continue to get worse, and if we reach 2C, droughts will get worse in eastern Australia too.

Although the number of cyclones might decrease, their average intensity is expected to increase.

The next part of the IPCC report, released next year, will focus on the impacts of climate change, and we'll hear a lot more about that then.

What can be done about climate change?

While the IPCC's report makes for grim reading, there are some reassuring details.

It isn't too late to secure a future where warming is kept below 1.5C and we avert many of the most worrying impacts.

In November the world is gathering at the COP26 climate change conference in Glasgow, Scotland. Countries are expected to "ratchet up" their pledges to cut greenhouse gas emissions in line with their promise to try to stop warming at 1.5C.
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For that to work, countries like Australia need to reach net zero emissions before 2050 so that the whole world can hit that milestone by 2050.

But crucially, near-term targets need to be in line with that goal.

Australia has a 2030 target to cut emissions to 26 per cent below 2005 levels, yet continues to approve new coal and gas projects.

UN secretary-general Antonio Guterres says the IPCC findings must "sound a death knell for coal and fossil fuels, before they destroy our planet".

IPCC vice chair Mark Howden says the world needs to cut emissions by about 45 per cent by 2030 — and of course, rich countries need to move faster than others.

Conservation groups argue Australia needs to slash emissions by 75 per cent this decade.

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(AU The Guardian) Coalition’s Misleading Tactics Will No Longer Cut It – The IPCC Report Shows Our Future Depends On Urgent Climate Action

The Guardian - 

The Morrison government’s ‘technology, not taxes’ mantra ignores the fact that taxes pay for technology, and affordable technology can make a difference

A car is submerged by flood water in Traralgon, Victoria in June 2021. The IPCC report predicts parts of Australia will be more prone to drought, while others will see more severe storms and increased flooding. Photograph: James Ross/AAP

How many wake-up calls on the climate does Australia need?

It is an unanswerable question, of course – we’ve been here too many times before to pretend otherwise – but everyone should read the summary of the latest report by the Intergovernmental Panel on Climate Change, regardless.

Using careful scientific language, it tells the story of what is happening across the planet with a bracing clarity that is at once familiar and alarming.

From an Australian perspective, it confirms that on average temperatures are 1.4C hotter than early last century. It is unequivocally – unarguably, unambiguous and indisputably – due to human influence.

Deadly heatwaves have increased, there are more extreme fire days, the bushfire season is longer and sea levels are rising faster than the global average, pushing back the shoreline in many places. There is a high confidence that all of this will get significantly worse.

There is also high confidence that emissions have already slashed rainfall in southern WA, where it will become drier and more drought prone under all scenarios. In the east, rainfall is down in the cooler months and droughts will get worse if the temperature rises to 2C.

When the rain does come, it will really come – there will be more damaging extreme storms, and river flooding is expected to increase.

We know all this, of course – the IPCC report is an authoritative statement on research that has already been published.

We know the catastrophic bushfires that burned across Australia two summers ago were the most extensive on record and had a climate signal. We know the Great Barrier Reef suffered three mass coral bleaching events in five years. We know the country’s ecosystems are being pushed to the edge. We know that seasonal changes linked to climate change led to farm profits in Australia falling 23% over 20 years.

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And we know damage across the planet in this extraordinary year is consistent with previous scientific warnings.

An unprecedented heat dome over the American Pacific north-west, wildfires in Europe and North America, devastating floods in western Europe and China, a climate-linked famine in Madagascar – this is how it happens, how we have been told for years it will happen.

Recent studies suggest there are signs that the Gulf Stream is losing stability, that a study found the Amazon – which by rights should be a massive carbon sink – has been releasing more carbon dioxide than it absorbs, and that a destabilisation of the massive Greenland ice sheet is likely under way. Each would be a tipping point with global consequences.

It is worth remembering that the IPCC is by nature a conservative organisation, in the true sense of the word. The report is the work of 234 scientists based on evidence from more than 14,000 peer-reviewed scientific papers, and signed off by the world’s governments, including Australia. In the past, the reality of climate change has at times outpaced the IPCC’s published consensus.

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Without ever straying into politics, the latest report illustrates the vast gulf between what qualifies as climate policy and debate in Australia and what is required to address the problem. The Morrison government’s response to criticism of its climate performance is to list what it says is evidence of action where there is next-to-none. It gets away with this, in part, through tricks of carbon accounting.

As Scott Morrison said in parliament on Monday, the most recent national greenhouse accounts released in June suggests emissions have fallen 20% over the past 15 years, a statistic that you could assume represents some (limited) progress.

In reality, as analyses by government officials and others have shown, fossil fuel use in Australia has barely moved. The government has been able to claim it is taking action purely because the historically rapid rate of forest clearing for farming, logging and development slowed – but not stopped – earlier this decade.

This land-based fall in emissions mostly happened under Labor, not the Coalition, and mostly had nothing to do with federal policy. It was possible only because Australia has not yet finished cutting down its native forests. Most other wealthy nations were cleared centuries ago.

Here is the key point, as spelled out this week in a study by energy analyst Hugh Saddler: if changes in farming and land-clearing are excluded, fossil fuel emissions in Australia increased by more than 6% between 2005 and when Covid-19 struck. Try selling that number as evidence of an inevitable economic transformation under way.

It makes the government’s target of cutting emissions by at least 26% by 2030 compared with 2005 appear particularly hollow. The goal, unchanged in six years, looks worse again when held up against recent commitments by G7 countries to make minimum cuts of between 40% and 63% over the same period, and entirely without basis when measured against the rapidly advancing science of the IPCC.

The government’s response on Monday was to repeat its mantra that “technology, not taxes” could solve the problem. It’s a slogan that ignores that taxes pay for technology development, and technology that can make a difference already exists and, in the words of the ClimateWorks Australia chief Anna Skarbek, is in many cases “mature and available”.

The world still needs better technology, but it also needs policy that deploys the available technology at a pace that recognises the scale of the threat.
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With less than three months until the Cop26 global climate conference in Glasgow, the main question being directed at the Morrison government on climate is whether it will belatedly join more than 100 other countries in adopting a target of reaching net zero emissions by 2050, and lay out a plan to get there.

The IPCC report makes clear the main game is what countries – and particularly the biggest 20 or so emitting nations including Australia and, yes, China – are willing to do now.

This still matters because, though it may be easy to miss amid the dire headlines, the report lays out some reason for hope, however qualified. The crisis is in motion, with some changes in oceans and ice possibly irreversible for millennia, and global heating of 1.5C above pre-industrial levels – a benchmark enshrined in the Paris agreement – is almost certain to be reached. But the scientists found aggressive action could see it dip back below that level later this century.

Scientists involved with the report are at pains to stress that, whatever the outcome, every fraction of a degree will make a difference.

Many of the world’s biggest developed countries now have commitments that could put the world on a 1.5C path if delivered and matched elsewhere. Business and global investors worth trillions are increasingly singing from a similar sheet, and not all of it is greenwash. More than ever, there are potential solutions within reach.

But the IPCC report shows there is no room for countries the size of Australia to engage in political sophistry based on misleading data, or to hide behind technology-focused delaying tactics that echo positions held by the Howard government nearly 20 years ago.

The scientists would never use this language, but its central point could be summarised as: the bullshit has to end.

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(AU SMH) Seven Top Takeaways From The IPCC’s Latest Climate Science Assessment

Sydney Morning Herald - Peter Hannam

Every seven years or so, like a recurring global spasm, scientists from around the world update their understanding of how the planet is heating up, what the impacts will be and what we might do about it.

Known as the Intergovernmental Panel on Climate Change, the resulting reports serve as what one contributing author calls a “golden book” of climate science in three volumes plus a synthesis report.

The first volume of the Sixth Assessment Report (AR6) was released on Monday and lays out in exacting detail in about 4000 pages how jamming our atmosphere with greenhouse gases is altering the climate.

What’s changed from previous Assessment Reports?


Temperatures, for one thing. The mean temperature at the surface – where we live – has warmed 0.24 degrees since the 2013-14 Fifth Assessment Report (AR5) evaluated data to 2011. Let’s call it a quarter. We’re now about 1.1 degrees warmer than the 1850-1900 baseline and, given the slow process of how our extra emissions trap more heat from the sun, we will heat further even if carbon dioxide, methane and other greenhouse gas pollution ceased today. (Spoiler: They won’t.)

Apart from more refined estimates, AR6 has stepped up regional forecasts including carving Australia into four zones. The blame humans carry for altering the climate – known as attribution research – also gets more prominence. (Spoiler: we are responsible for virtually all of it.)


 

Do these reports do much?


These IPCC reports aren’t meant merely to gather dust (though they do), but inform governments (Intergovernmental is a clue) and the public (that might nudge those policymakers to act).

Since the first assessment report (presciently dubbed FAR) in 1990 said, “the climate is warming, folks”, we’ve belched 1 trillion tonnes (1,000,000,000,000) of CO2 by burning fossil fuels and clearing land. It’s also 41 per cent of all the estimated emissions since 1750, so if it’s a pedal we’re hitting, it’s not the brake. Temperatures, particularly since the 1970s have been going one way, and the best climate models are doing an increasingly good job at matching observations.


 

1.5 degrees and all that


Remember Paris and that 2015 climate summit where almost 200 nations agreed to keep warming to between 1.5 degrees and “well below 2 degrees”? Well, this instalment of AR6 is meant to guide leaders when they gather (or Zoom into) a summit in the less glamorous Glasgow in November. (The other two reports, on impacts and what emissions action we could take, won’t land until next year.)


 
Remember, though, that 1.5 degrees and 2 degrees are both arbitrary. Look at Greece this week, Canada or California last month, or our home-fired Black Summer last year to get a glimpse of how juicing the climate is already raising the odds of extreme nasties. Heatwaves are one of them.

Oh, and as the 1.5-degree target represents a 20-year average, don’t be surprised if we cross that marker in an El Nino year (when the Pacific Ocean unhelpfully doesn’t absorb as much heat and gives some back) this decade. We hit that mark in a month during the 2015-16 El Nino, according to the Bureau of Meteorology’s Blair Trewin.

As the atmosphere’s greenhouse gas concentration rise, we’re trapping more heat and energising our weather systems. Credit: Nick Moir

Barbecued and soaked Australia


The improved resolution of climate models has allowed this IPCC report to provide a closer look at how regions of the world might fare as the planet heats up.

Land warms faster than the ocean, and that happens to be where most of us live. In Australia, we’ve warmed about 1.4 degrees so far, since 1910. Projected warming doesn’t make for a happy scene, particularly for maximums, and that’s not considering heatwave spikes.



Rainfall is likely to be heavier when it comes, as the atmosphere holds about 7 per cent more moisture per degree. Unfortunately, southern Australia will remain on its drying trend, particularly in winter, as west-to-east storm tracks shifting closer to Antarctica. Other unpleasant outcomes await those living near the coast as sea levels rise, while the “intensity, frequency and duration of fire-weather events are projected to increase throughout Australia” the report states with “high confidence”.

Mid-century carbon neutrality?


The third AR6 report will explore in more detail what fossil pathways we might saunter down, but this one gives us a taste of what we can expect. It presents five specific options, ranging from low to high emissions, and includes methane, nitrous oxide (think fertiliser) and other heat-trapping gases.

Taking the lowest scenario (awkwardly named “shared socio-economic pathway”) won’t get us to net-zero emissions or so-called climate neutrality this side of 2050.



Remember, that target is what many rich nations have signed up for, while the Morrison government says it’s a “preferred” goal. Better not get stuck on a higher or moderately high emissions path or we’ll never get there.

So, how much can we burn?


Let’s say every time you flip on an electric toaster or drive your car (assuming you’re not offsetting both by buying renewable energy or planting a tree, or so on), you’re helping warm up our planet. (Big picture: every trillion tonnes of CO2 likely causes a best-estimate of 0.45 degrees warming.)



Now, we burn or emit about 42 billion tonnes of CO2 a year. The AR6 report puts a range of probability risks around what we might aim for. If it’s to keep warming to 1.5 degrees or stay thereabouts, and we think we’d like a 50-50 chance, then we have 500 billion tonnes of C02 to go, or 12 years of current pollution levels.

Or as Andy Pitman, director of the ARC Centre of Excellence for Climate Extremes puts it: “I don’t want my future based on the toss of a coin.” Who flies in a plane with a 50 per cent of crashing?

Tipping points and other unfathomables (for now)


Professor Pitman is not alone in thinking we’re all but set for 1.5 degrees of warming. Pep Canadell, one of the AR6 report authors and senior CSIRO researcher says “there’s a lot of warming all the way to 2050. And it’s coming fast”.

The report, if anything, errs on the side of caution, noting the limited data on so-called “low probability, high impact” events such as the disintegration of Antarctic ice sheets (think more than 15 metres of sea-level rise) or the halt of the Gulf Stream. For the latter, (fancy name: Atlantic Meridional Overturning Circulation), the report says “there is medium confidence that there will not be an abrupt collapse before 2100″. Not so reassuring if you live in northern Europe.


 
Extreme weather
Australian weather extremes to get more extreme as climate heats: IPCC

What keeps people like Professor Pitman awake at nights, though, is the prospect that the biosphere won’t behave as it has for the past couple of centuries of our carbon-plus experiment.

The AR6 report notes that as emissions rise, the land and ocean won’t be so cooperative and take up as much of the extra emissions we’re sending up.

“That’s a big, big deal,” he said. “The specific human cuts of emissions necessary to achieve any particular CO2 level becomes harder.“

If the atmosphere keeps it, we’d better come up with some good ways to take it back out, and fast.



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