John French is Atmospheric Physicist at the Australian Antarctic Division, University of Tasmania
Andrew Klekociuk is Principal Research Scientist, Australian Antarctic Division, and Adjunct Senior Lecturer, University of Tasmania
Frank Mulligan is Associate Professor, Maynooth University, Ireland
While greenhouse gases are warming Earth’s surface, they’re also
causing rapid cooling far above us, at the edge of space. In fact, the
upper atmosphere about 90km above Antarctica is cooling at a rate ten
times faster than the average warming at the planet’s surface.
Our new research
has precisely measured this cooling rate, and revealed an important
discovery: a new four-year temperature cycle in the polar atmosphere.
The results, based on 24 years of continuous measurements by Australian
scientists in Antarctica, were published in twopapers this month.
The findings show Earth’s upper atmosphere, in a region called the
“mesosphere”, is extremely sensitive to rising greenhouse gas
concentrations. This provides a new opportunity to monitor how well
government interventions to reduce emissions are working.
Our project also monitors the spectacular natural phenomenon known as
“noctilucent” or “night shining” clouds. While beautiful, the more
frequent occurrence of these clouds is considered a bad sign for climate change.
‘Night shining’ clouds photographed by the lead author John French from Davis station in 1998.Author provided (No reuse)
Studying the ‘airglow’
Since the 1990s, scientists at Australia’s Davis research station
have taken more than 600,000 measurements of the temperatures in the
upper atmosphere above Antarctica. We’ve done this using sensitive
optical instruments called spectrometers.
These instruments analyse the infrared glow radiating from so-called
hydroxyl molecules, which exist in a thin layer about 87km above Earth’s
surface. This “airglow” allows us to measure the temperature in this
part of the atmosphere.
Spectrometer in the optical laboratory at Davis station, Antarctica.John French
Our results show that in the high atmosphere above Antarctica, carbon dioxide and other greenhouse gases do not have the warming effect they do in the lower atmosphere (by colliding with other molecules). Instead the excess energy is radiated to space, causing a cooling effect.
Our new research more accurately determines this cooling rate. Over
24 years, the upper atmosphere temperature has cooled by about 3℃, or
1.2℃ per decade. That is about ten times greater than the average
warming in the lower atmosphere – about 1.3℃ over the past century.
Untangling natural signals
Rising greenhouse gas emissions are contributing to the temperature
changes we recorded, but a number of other influences are also at play.
These include the seasonal cycle (warmer in winter, colder in summer)
and the Sun’s 11-year activity cycle (which involves quieter and more
intense solar periods) in the mesosphere.
One challenge of the research was untangling all these merged
“signals” to work out the extent to which each was driving the changes
we observed.
Surprisingly in this process, we discovered a new natural cycle not
previously identified in the polar upper atmosphere. This four-year
cycle which we called the Quasi-Quadrennial Oscillation (QQO), saw
temperatures vary by 3-4℃ in the upper atmosphere.
Scientists used sensitive equipment to monitor the upper atmosphere from Davis station.John French, Author provided (No reuse)
Discovering this cycle was like stumbling across a gold nugget in a
well-worked claim. More work is needed to determine its origin and full
importance.
But the finding has big implications for climate modelling. The
physics that drive this cycle are unlikely to be included in global
models currently used to predict climate change. But a variation of 3-4℃
every four years is a large signal to ignore.
We don’t yet know what’s driving the oscillation. But whatever the
answer, it also seems to affect the winds, sea surface temperatures,
atmospheric pressure and sea ice concentrations around Antarctica.
‘Night shining’ clouds
Our research also monitors how cooling temperatures are affecting the occurrence of noctilucent or “night shining” clouds.
Noctilucent clouds
are very rare – from Australian Antarctic stations we’ve recorded about
ten observations since 1998. They occur at an altitude of about 80km in
the polar regions during summer. You can only see them from the ground
when the sun is below the horizon during twilight, but still shining on
the high atmosphere.
The clouds appear as thin, pale blue, wavy filaments. They are
comprised of ice crystals and require temperatures around minus 130℃ to
form. While impressive, noctilucent clouds are considered a “canary
in the coalmine” of climate change. Further cooling of the upper
atmosphere as a result of greenhouse gas emissions will likely lead to
more frequent noctilucent clouds.
There is already some evidence the clouds are becoming brighter and more widespread in the Northern Hemisphere.
The new temperature cycle is reflected in the concentration of sea ice in Antacrtica.John French
Measuring change
Human-induced climate change threatens to alter radically the
conditions for life on our planet. Over the next several decades - less
than one lifetime - the average global air temperature is expected to
increase, bringing with it sea level rise, weather extremes and changes
to ecosystems across the world.
Long term monitoring is important to measure change and test and
calibrate ever more complex climate models. Our results contribute to a
global network of observations coordinated by the Network for Detection of Mesospheric Change for this purpose.
The accuracy of these models is critical to determining whether
government and other interventions to curb climate change are indeed
effective.
Climate policy director Rhiana Gunn-Wright, architect of the Green New
Deal, explains the connections between the pandemic and the climate
crisis.
Rhiana Gunn-Wright at the DealBook/DC Strategy Forum in Washington last year. Credit...Michael Cohen for The New York Times
“It’s actually easier in a lot of ways to talk about climate change now.” — Rhiana Gunn-Wright, climate policy director
Rhiana Gunn-Wright had asthma growing up.
So did many of her neighbors in Englewood, on the South Side of Chicago, where pediatric hospitalization rates for asthma were significantly higher
than the rate nationwide in the early 2000s. Ms. Gunn-Wright had so
many friends with asthma that she assumed it was a “childhood disease”
that all young people had.
Only later in life did she realize it was linked to air pollution in the area, as was shown by research funded by the Environmental Protection Agency.
For some policymakers and advocates, even those organizing global climate strikes,
the effects of climate change can feel distant, but Ms. Gunn-Wright,
30, never had that luxury. Her work on environmental justice has always
felt personal, tied to the public health problems in her community.
In
2018, Ms. Gunn-Wright was recruited by the progressive think tank New
Consensus, which focuses on climate and economic policy, to be a
co-author on a paper titled “The Green New Deal.”
It laid out in
detail a sweeping platform to fight climate change, and it was the basis
of a congressional resolution introduced by Senator Edward Markey,
Democrat of Massachusetts, and Representative Alexandria Ocasio-Cortez,
Democrat of New York. The resolution outlines a 10-year mobilization to
achieve net-zero greenhouse gas emissions while creating new jobs and
investing in infrastructure, galvanizing “every aspect of American
society at a scale not seen since World War II.”
The Green New Deal quickly became a lightning rod
among lawmakers. While Republicans cast it as a socialist plan to take
away cars and planes, some Democratic presidential candidates embraced parts or all of the framework, and it was credited
with encouraging spirited debate on climate policy during the 2020
primary race. Still others critiqued it for its breadth — and many of
its specifics, including cost, are still in question.
A
year later, the country is in the midst of new crises — a pandemic and
an extraordinary economic downturn, amid waves of protest against
systemic racism.
In Her Words spoke
with Ms. Gunn-Wright about how the coronavirus has made climate issues
even more stark, and about the challenges of leading as a Black woman in
the predominantly white male world of environmental policy.
The conversation has been condensed and edited for clarity.
You’ve
been sounding the alarm on climate change for some time. Now the
headlines are all about the coronavirus. Has it gotten trickier to focus
public attention on climate amid the spread of Covid-19?
In
some ways, it’s easier to talk about climate change than when we first
came out with the Green New Deal resolution. That’s because the connections
between the pandemic and climate crisis are clear, starting with the
fact that people of color — Black and Latino folks — are dying at far
higher rates from Covid. And there’s already at least one study showing how Covid deaths are correlated with exposure to toxic air pollution.
It’s
never normal to surround people with toxic air pollution and cause them
all sorts of respiratory problems, but before Covid that was the normal
drumbeat of injustice. I think Covid has helped break that
normalization.
Are you hopeful that some of the positive climate shifts in recent months, like our decreased reliance on air and car travel, will continue after the pandemic?
No,
because they’re due to reductions in economic activity and not to
policy change. Emissions go down during recessions as a result of
decreased economic activity, but they always rebound. You’re going to
see them kick into overdrive.
The field of environmental research and policy has long skewed white and male.
Columbia University’s earth observatory just appointed its first-
female interim director this month. What are some of the hurdles you’ve
faced as a Black woman in this line of work?
I
had to downplay my Blackness and my own anger. I had to depoliticize
myself. Sometimes the connections that I talked about, between equity
and the environment, weren’t taken seriously, so I wasn’t taken
seriously.
I had at least one white
man tell me that if we didn’t mitigate climate change, it would be my
fault because the Green New Deal tied in equity and race, and that’s too
much, so I will have ruined our changes at climate policy.
How did you respond to that?
I didn’t. Because what climate policy did I interrupt that was happening? There wasn’t anything happening at the federal level.I
had a white man write me a multiple-page essay about how we have to
tackle the climate crisis because it’s the most urgent thing facing
humanity. But racial injustice, he wrote, has always existed, so why do
we have to address that now? The
way I responded was by doubling down. It became clear to me that part of
my work is about elucidating these connections between climate and
justice.
How are you working to put climate change and justice at the center of the country’s response to Covid-19?
I’m
working on a paper now about green stimulus. It’s spelling out what an
economic recovery looks like that is based in climate justice. Climate
policy is often thought of as a very long-term thing, so we’re making
the case for how it can be used for immediate stimulus and fit into our
plans to rebuild the economy.
You’ve
been both a political insider and outsider — working for candidates and
as a researcher and organizer. Where do you get the most traction?
I
sometimes feel that it is easier to do my work outside of the system,
because it’s easier to be myself. The work I do is stressful, and the
ability to look in the mirror and recognize myself and to act in ways
aligned with my values is really important to me.
What parts of yourself have you had to quiet while working inside political institutions?
The
way I dress. My aesthetic is “just dropped off my kids and going on a
Target run,” but I also have a half-sleeve tattoo and a nose ring. I’ve
never seen a person on the inside, like a chief of staff or legislative
director, with a sleeve tattoo. I’m very open about calling out white
supremacy. And I have mental health issues: I have PTSD, anxiety and
depression. I have yet to see a leader, that is someone on the inside,
talk about that.
The closer you get to the inside, the more the models
of leadership and professionalism become exclusionary and focus on a
dominant white male leader. I’m at this point in my life where I’m not
willing to become a narrower person in order to gain power.
Speaking
of people on the inside, Joe Biden, the presumptive Democratic
presidential nominee, hasn’t fully endorsed the Green New Deal, but he
did just release a sweeping set of climate policies. You’ve been critical of his new platform. Why is that?
I
think it has great elements, but it tries to be transformative while
keeping the power relationships that we have in our economy. I think
returning power to marginalized communities is very important as part of
climate action. For example, if Indigenous communities had the rights
that they deserved, if their treaties were respected, we wouldn’t even
be thinking about a Dakota Access Pipeline.
Some climate experts say there is a connection between women and environmental action. Why are women more likely to bear the brunt of climate disasters?
Actually,
gender is a place where we need to strengthen our analysis. We haven’t
done enough thinking about the care economy. Care jobs are green jobs,
in the sense that they are low carbon emission jobs. And with Covid, it
has become clear how broken our care economy is. On the child care side,
it could very well be decimated. Family child care providers are
closing and won’t have the support to reopen.
With the Green New Deal,
we elevated manufacturing jobs and construction, which are important,
but it often feels like it’s about saving men’s jobs and the women don’t
appear. When there was a gender gap in the original Green New Deal, the
Feminist Green New Deal Network stepped in and started thinking through its impact on women. So I’ve been in conversation with them more and learning so much.
We all claim to love the planet, but do we really? It’s easy to love
something when it’s lavishing you with refreshing hikes, clear lakes,
and gorgeously glowing sunsets. It’s much harder when the object of your affections asks for something in return — such as your toilet paper.
It isn't news that pollution and climate change are threatening our planet. Scientists have been screaming that our lifestyles are unsustainable
for decades, begging people to be more mindful in their consumption.
Yet habit and convenience has caused us to largely ignore these dire
warnings, continuing to use paper coffee cups and burn fossil fuels like
there’s no tomorrow. At this rate, there might not be.
There are of course limits to individualaction (and carbon footprints are a sham). Wider policy changes and changing company behaviour are essential to achieving true sustainability, with just 20 companies
currently responsible for a third of all greenhouse gas emissions. A
2017 study found that 71 percent of global emissions were generated by
just 100 companies, highlighting the importance of pressuring companies to go green.
Even so, if you're looking for tiny ways to show big companies that
people do actually care about not destroying the planet, we can help.
Here are six embarrassingly simple ways you can dial up your own
sustainable lifestyle and lessen your personal impact, but which you
still won’t do because they're bothersome.
1. Use a bidet
Many of us are comfortable wiping our asses with toilet paper,
smearing our feces across tissue like disgusting abstract
expressionists. However, if we are open and willing to learn, there is a
better way. Muslims, Asians, and Europeans
have been way ahead on bathroom hygiene for ages, and it’s time
everyone else caught up — for both the environment and our buttholes.
Not only do bidets give you a more thorough, hygienic clean
than toilet paper, they’re also more sustainable. Exactly how much
water is used to manufacture toilet paper depends upon the method, with
estimates ranging from six to 37 gallons for a single roll. However, mostconclude that bidets consume significantly less, at around one eighth of a gallon per use.
Overall, bidets seem like a much less wasteful choice. However, Dr. Tommy Wiedmann,
professor of sustainability research at UNSW Sydney, noted that the
positive impact of the bidet would depend on how people use it. Blasting
your anus like a fire hose for an hour is unlikely to do anyone any
good.
2. Turn off the tap when you brush your teeth
As a citizen of perpetually drought-stricken Australia,
learning that people leave the tap running while brushing their teeth
was like learning people fertilise their lawns with wagyu beef. The EPA
states that leaving the faucet on can waste eight gallons of water per
day. That’s a ridiculous amount of precious liquid literally going down
the drain.
It’s hard to break habits, but there’s absolutely no reason to
continue this one. Both Wiedmann and University of Sydney sustainability
researcher Dr. Lisa Heinze
told Mashable you should definitely turn off the tap while taking care
of your dental hygiene. Though water is technically a renewable
resource, there's a limited amount that's fresh and unpolluted, and it
isn’t always available everywhere. Saving what we have is important.
Saving water will save you money, too, in case you need a more capitalist motivation to care about the world.
3. Use public transportation
Complaining about public transportation is a universal experience
that unites us all. Buses are always late, trains are unspeakably
filthy, and both are packed with coughing strangers who don’t believe in
personal space. We jump at the chance to avoid public transport
whenever we can. Unfortunately, embracing that contemptible subway is
one of the best things you can do to save the planet.
“Transport is still the second largest emitter of greenhouse gases
globally, after the electricity and energy sector, representing 15
percent of the world’s total greenhouse gas emissions,” Dr. Chris De Gruyter told Mashable. De Gruyter is a vice-chancellor's research fellow at RMIT University’s Centre for Urban Research in Melbourne.
“In the United States, half of all trips are three miles or less, but
72 percent of these are by car; for trips of one mile or less, 60
percent are by car,” De Gruyter said.
Wiedmann considers using public transport “the most beneficial to
help with curbing climate change” out of all the actions on this list,
“especially when combined with having no car at all.” Recent research
found living car-free has some of the highest potential to mitigate a
person’s carbon emissions, even better than switching to a vegan diet.
According to the EPA, the average car emits around 4.6 metric tons of carbon dioxide every year.
If you absolutely must drive, Heinze advised using a car-share program rather than owning your own. Babet de Groot,
a Ph.D. candidate studying ocean governance and waste management at the
University of Sydney, further suggested carbon offsetting when such
travel is unavoidable.
“Carbon-offsetting is the purchase of compensation for emissions
generated, which is used to fund emissions-reduction elsewhere,” de
Groot said. “Plant trees to offset your carbon emissions via Offset Earth or Carbon Neutral Charitable Fund.”
4. Stop buying bottled water
Filling a bottle with tap water and carrying it with you only
requires a tiny bit of forethought and prep. Even so, countless people
still refuse to do this bare minimum, preferring to buy single-use
plastic bottles of water they’ll throw in the trash by nightfall. This
is the type of hedonism that will doom humankind, and we will deserve
it.
“Annual production of plastic bottles is projected to reach 600
billion by 2021,” de Groot told Mashable. “That is 600 billion bottles,
in addition to almost all plastic produced to date, that will virtually
persist in the environment forever.”
According to de Groot, humans produced over 7,800 million tons of new
plastic by 2015. Of that, approximately 79 percent has gone into
landfill or the natural environment. It takes over 500 years for plastic
to degrade into smaller particles, but it continues to destroy the
environment even then. “These microplastics risk being ingested by
wildlife and transferred up the food chain where their effects on human
health are yet to be known,” de Groot told Mashable.
You don’t need plastic bottles of Himalayan spring water blessed by a
108-year-old monk who doesn’t use YouTube. If you’re really concerned
about purity, just boil and filter your tap water.
5. Ignore ‘best before’ dates on food
Eating food past its manufacturer mandated “best before” date feels
like dancing with the devil in the pale moonlight. Food poisoning is
never fun, and defying those authoritatively stamped numbers may seem
too close to spitting at the gastrointestinal gods. However, strict
adherence to these dates is actually unnecessary, and only serves to
create equally unnecessary food waste.
The U.S. Department of Agriculture
states that, with the exception of infant formula, food is still safe
to consume after the provided date passes — as long as it shows no signs
of spoilage such as "an off odor, flavor or texture." Eat, drink, and
be merry. There is no uniform standard regarding product dating in the
U.S., so the numbers largely mean nothing. "Use by" and "best before"
dates only indicate when food is at its best quality, not when it is
safe to eat.
“Confusion over the meaning of dates applied to food products can
result in consumers discarding wholesome food,” says the USDA.
“The United Nations Food and Agriculture Organisation estimated that
industrialised countries generate approximately 95 to 115 kgs [209-254
lbs] of consumer food waste per capita,” de Groot told Mashable. “This
contributes to climate change in the form of methane emissions emanating
from landfills and carbon emissions associated with production,
processing and transport.”
Learn to trust your senses rather than uncritically obey “best before” dates, and you can help reduce some of that waste.
6. Vote
Voting is a chore, and not one that feels particularly rewarding in
the moment. Standing in line for hours just to tick a few little boxes
might seem irritating, like lost time that might have been spent working
or binging Project Runway. However, just like any other chore,
it’s important that you do it anyway — especially if you want to keep
your environment habitable.
“If we want the right conditions, policies, rules, and support
structures to be able to live sustainably, we need our leaders to be
part of the solutions,” Dr. Simon Lockrey told Mashable. A sustainable design researcher at RMIT University, Lockery is also a board member of the International Sustainable Development Research Society.
“Our votes matter, so we should be using that mechanism to send them a
message. The old way is not necessarily the best way. By voting, or when
we really need to, protesting, we can send these types of messages.”
"[Individual changes] should be a starting point to increased action in our communities, governments, schools and workplaces."
Practically all government policies impact the environment in some
way, but Lockery notes some of the most significant issues concern
energy, waste, forestry, water, and agriculture. These affect “big
ticket items for living sustainably,” such as climate change, threats to
habitats or certain species, and environmental toxicity.
“What we should be pressuring governments to support are policies
that build energy systems that are clean; that drive less greenhouse gas
production in industry; that protect flora and fauna; and eradicate
toxic materials/chemicals from our biosphere,” said Lockery.
“Policies need to do this internationally, at an industry level, as
well as support us as individuals to contribute, such as supporting
household renewable energy, or enabling a waste system that goes beyond
household recycling to being regenerative or truly circular,” he added.
Of course, voting isn’t easy for everyone. Voter suppression
remains a widespread problem in the U.S., with many potential voters
unable to access polling booths on election day (which isn't even a
national holiday). However, if you're privileged enough that you can
cast your ballot with ease, it’s one of the most important things you
can do to save the planet.
“Voting and protesting are benefits of a democracy, and thus are good
ways to call for change,” said Lockery. “We should cherish these
activities, as many don't have these options available to them.”
“Overall, we in the developed world are simply consuming too much;
too many products we don’t really need, too many holiday flights, et
cetera,” Wiedmann told Mashable. “Therefore, in addition to doing these
‘easy’ things, we should generally look at reducing our overall
consumption, by buying less stuff, flying less, living in smaller
houses, maybe growing our own food.”
Of course, not everyone will find these suggestions feasible. As
Heinze notes, “You can't realistically take public transportation if
your commute will take three-times as long.”
“This does not mean we should not embrace individual changes, but
that they should be a starting point to increased action in our
communities, governments, schools and workplaces,” Heinze continued. “If
you're looking to make the biggest impact on the climate for the least
amount of effort, a great place to start is divesting your [retirement
fund] from fossil fuels, and encouraging your institutions to do the
same."
An report by experts is out today and aims to improve bushfire responses. (AAP: Dan Peled)
Key Points
A group of 150 experts and bushfire survivors came together in June and July to discuss improvements to bushfire preparation
There are more than 165 recommendations in the Australian Bushfire and Climate Plan report out today
One key recommendation is a climate disaster fund financed by a fossil fuel levy
Former emergency leaders, climate scientists, doctors and community members are calling on the Federal Government to impose a levy on the fossil fuel industry for a climate disaster fund to help pay for the impact of natural disasters.
It comes as part of 165 recommendations by the Emergency Leaders for Climate Action (ELCA), a group of more than 150 experts and affected community members, in a bid to improve bushfire readiness, response and recovery.
It follows the ELCA National Bushfire Summit, which took place in June and July — and it's hoped the findings will be included in the royal commission report, which is due to be handed to the Government next month.
Former NSW Fire and Rescue commissioner Greg Mullins is calling for a fossil fuel levy. (ABC News: John Mees)
"The escalation in natural disasters is driven by climate change," he said.
"There should be a levy on the fossil fuel industry, given all their tax breaks.
"We had the hottest, driest year ever — a year that would not have happened without the impact of climate change.
"It drove the worst bushfires in Australia's history — they were bigger, hotter, faster and more destructive [than] what we've ever experienced before."
"The fires were weather driven and the weather was driven by a warming climate," Mr Mullins said.
'Rapidly escalating threat'
The report, the Australian Bushfire and Climate Plan, to be released later today, describes a "new bushfire era where we must fundamentally rethink how we prepare for and manage this growing threat".
"There is no doubt that bushfires in Australia have become more frequent, ferocious and unpredictable," the report states.
"Sadly, those warnings fell on deaf ears and, as the world watched on in horror, those same warnings became a harsh reality."
The ELCA, which includes former emergency services commissioners from all over Australia, has accused the Federal Government of underestimating and ignoring "the rapidly escalating threat of climate change".
"Consequently, our land management, fire and emergency services are under-resourced, disaster recovery is under-resourced and communities are underprepared for the worsening bushfire threat," the report said.
"Communities and ecosystems were already being pushed beyond their ability to adapt."
Luke Wright takes a rest after putting out spot-fires at his brother's home in Oakdale, in Sydney's south-west, in December. (ABC News: Selby Stewart)
The group said its recommendations would cost billions of dollars to implement.
It is calling for greater funding for firefighting and land management to ensure faster identification and dousing of new fires.
The report identifies a gap in aerial firefighting resources, specifically CL-415s — so-called "Super Scoopers" — that can drop 6,000 litres of water or firefighting foam at a time.
"We need a large number of these," Mr Mullins told the ABC.
Mr Mullins says more aerial firefighting resources are needed. (Reuters: Mike Blake)
The group is also advocating for an Indigenous-led National Cultural Fire Strategy, and greater action to address the health effects of bushfires.
Smoke from the recent bushfires resulted in more than 400 deaths and another 4,000 people being treated in hospital, the ELCA said.
The Federal Minister for Emergency Management has been contacted for comment.
Report raises concerns around seawalls’ cost and effectiveness as low
pressure system to batter NSW coastline with high tides and huge waves
Coastal beach erosion and home damage at Wamberal on the NSW Central Coast. A report says a trade-off of protecting about 60 beachfront properties with a seawall would be a potential drop in visitors due to loss of the beach. Photograph: Carly Earl/The Guardian
A cost-benefit analysis of options for a seawall at Wamberal beach commissioned by the New South Wales government in 2017 found that none of the six engineering options considered would deliver a net public benefit and that erosion would only increase with rising sea levels.
“A seawall will provide benefits to beachfront properties by reducing the impacts of coastal processes,” the report by Marsden Jacobs found.
“However, in the longer term, more properties in this area are likely to experience greater damage and loss of property values from the increased flooding of Terrigal lagoon associated with sea level rise.
“Higher sea levels will result in the increasingly frequent
inundation of hundreds of properties surrounding the Terrigal lagoon,
the loss of the beach, and impacts on council assets such as water,
electricity, sewerage and roads,” it found.
“The key beneficiaries from construction of a seawall are the approximately 60 owners of beachfront properties at Wamberal.”
As the Central Coast of NSW braces for another lashing today, the
state government is still sitting on another report by the NSW coastal
council, commissioned by the local government minister, Shelley Hancock,
which looks at the vexed problems of seawalls and coastal erosion in
the state.
Councils up and down the coast face a dilemma: should they require
their entire ratepayer base, which often includes many retirees, to
support costly seawall projects that often involve ongoing requirements
for beach replenishment?
Or should councils be looking at adaption strategies
that accept that coasts are dynamic – some areas such as Wamberal,
Collaroy, Byron Bay and Port Stephens more so than others – and that the
battle to protect inappropriately located development will become even
more difficult due to sea level rise?
Letting
properties slide into the sea is politically unpalatable and the cost
of buying up the waterfront properties far more expensive than it was 50
years ago when the first problems emerged.
Former coastal council
member and engineer Angus Gordon says the answer lies in changing the
Local Government Act to allow councils to recoup the costs of the
seawall from waterfront property owners over time, though a long-term
levy on the affected properties.
Other schemes, at Collaroy, have involved subsidies from state and
local government, with waterfront home owners still facing $400,000
bills to build the wall.
Yet there remains concerns about both the environmental impact of seawalls and how they will perform in the future.
The Marsden Jacobs study on Wamberal was informed by a detailed study
by the then-NSW Office of Environment and Heritage, which found that
the coastal processes acting on the dune that separates Terrigal lagoon
from Wamberal beach – and where the most vulnerable houses are located –
are complex and will get worse with sea level rise.
It found that without a wall, 82 properties in the study area are
likely to be affected by coastal processes over a 20-year timeframe, and
92 properties over 50 years.
In May this year, Central Coast council commissioned Manly Hydraulic
Laboratory to design a concept plan for a seawall solution. The $400,000
study is being funded by both the state government and council. Another
company, Royal Haskoning DHV, looked at short-term measures.
But as the Marden Jacobs report detailed, the trade-off from
protecting about 60 beachfront properties with a seawall would be the
potential loss of visits due to the loss of the beach.
“This loss of visitors may create some concern in the wider Central
Coast local government area, especially as 32% of the beachfront
properties that would potentially be protected by a seawall (at the
expense of the beach) are only occupied occasionally,” Mardsen Jacobs
said.
The report considered a range of structural engineering approaches to
protect beachfront properties and other infrastructure at Wamberal
beach and the surrounding lagoon properties from the effects of coastal
processes.
It found that none of the engineering options considered provided a
net public benefit for the local community. This is because all of the
seawall options would result in the loss of beach areas, and without
sand replenishment the beach would quickly disappear, with significant
costs to the local tourism industry.
Marsden Jacobs said it was not clear which seawall option would lead
to the fastest loss of the beach but all would result in an unusable
beach by 2064, without a major sand replenishment program.
“The cost of sand replenishment is very high and outweighs the benefits of retaining a beach in front of a seawall,” it said. “Only a Planned Retreat option (Option 8) -retreat by managing the duration, type and intensity of future development within the coastal hazard area – provided greater benefits than a continuation of the current approach.”
The beach at Wamberal was vulnerable to erosion long before the first
homes were built. Terrigal lagoon sits directly behind Wamberal beach
and currently drains into the sea just to the south of the slipping
houses, but locals says the lagoon used to drain to the beach at a
different spot, suggesting active coastal processes.
Two storms in the 1970s – in May 74 and June 78 – saw several houses
on the strip claimed by the sea. Boulders rubbish, car bodies and the
remains of houses were dumped as a makeshift wall and the sand
eventually returned.
At that stage the council could have bought back properties. Instead
it continued to approve development, requiring new homes to have deep
piles into the sand.
Comment has been sought from Central Coast council. Links
There is an “unequivocal” link between climate change and the worst bushfire season on record, leading scientists have told a Senate inquiry.
Fire threatens homes along the Bells Line of Road in Bilpin in the NSW Blue Mountains. Picture: Jeremy Piper Source: News Corp Australia
Leading Australian scientists say there was an “unequivocal” link between last summer’s catastrophic bushfire season and climate change.
Speaking at Wednesday’s Senate inquiry into the 2019-2020 bushfire season, Bureau of Meteorology (BOM) chief executive officer Dr Andrew Johnson said “there’s no doubt” the planet was warming.
“There’s no doubt the causes of that warming have significant human footprint. That’s well established and scientific evidence is unequivocal,” he said.
He
said average temperatures had risen 1.4C since the turn of the century
while parts of the country had experienced a rapid decline in rainfall.
“How
that (global warming) translates to a severe weather event is a broad
field, (but) there are certain dimensions of the warming planet and what
we’re experiencing today that’s becoming clear,” he said.
In
January Prime Minister Scott Morrison and his Energy and Emissions
Reduction Minister Angus Taylor suggested the country did not need to
cut emissions more aggressively in a bid to stem global warming despite a
three-year drought and raging fires.
Average temperatures have risen 1.4C since the turn of the century. Picture: Jeremy Piper Source: News Corp Australia
Australia
contributes about 1.3 per cent of the world’s carbon emissions but
remains one of the largest carbon emitters per capita.
Dr Johnson said a rise in global emissions was driving up temperatures, which was likely to increase the risk of bushfires.
“Bushfires are starting earlier and ending later. There’s a climate signal in that,” he told the panel.
“How that plays out in the future will very much depend on how humanity responds.”
He said the bureau had provided extensive advice to government about the link between climate change, bushfires and emissions.
“We’ve been very clear and consistent in our advice to government across all three levels for many years,” Dr Johnson said.
“That advice is freely available to the general community.
Noting
the BOM’s submission, Queensland Senator Murray Watt said it had
provided more than 100 briefings about the bushfire risk to federal and
state governments in the months leading up to what would be the most
catastrophic bushfire season on record.
That included briefings about the risk associated with areas that were the hardest hit.
In January Prime Minister Scott Morrison and his Energy and Emissions Reduction Minister Angus Taylor suggested the country did not need to cut emissions more aggressively. Picture: NCA NewsWire / Gary Ramage Source: News Corp Australia
Dr
Johnson said the bureau provided “extensive briefings to all levels of
government leading into the summer”, spanning from daily updates to
forward briefings.
Committee chair Senator Tim Ayres questioned
several of the country’s most well-regarded scientists and scientific
bodies about one of the nation’s most “catastrophic events”.
Professor
Mark Howden, of the Climate Change Institute at the Australian National
University, said drought, high temperatures, low humidity and strong
winds all contributed to the development of extreme bushfires.
This is on top of the lowest rainfall and highest temperatures experienced on record.
“There’s
a long and strong link to reduced humidity due to climate change which
is projected to get worse in the future,” Prof Howden said.
“Each of these four major drivers will get worse … and the risks associated with climate change are growing.”
Leading Australian scientists say there is an ‘unequivocal’ link between last summer’s catastrophic bushfire season and climate change. Picture: WWF Source: Supplied
Professor
Jason Sharples, of UNSW’s School of Science, echoed those comments,
saying “what drives bushfires will increase due to global warming”.
“It’s hard to put an exact number on whether that will double or triple,” he said.
Prof Howden argued that Australia, along with the rest of the world, must reduce greenhouses gases.
“The question is whether we can extend that action (from the Paris Agreement),” he said.
Although, this summer could look a little different.
Dr Karl Braganza, the BOM’s head of climate change, said there was a potential for a La Niña event – the cooling of the Pacific Ocean – to occur this year.
He explained this could increase the risk of tropical cyclones and flooding.
Bureau of Meteorology chief executive officer Dr Andrew Johnson says ‘there’s no doubt’ the planet is warming. Picture: Nikki Davis-Jones Source: News Corp Australia
“We would have to increase provisions for those things,” he told the inquiry.
“All
going well, (it) would mean more rain and reduce the risk of bushfires
this summer. Having said that we haven’t seen the rain we expected to
fall in the recent months.
“We are watching conditions as they unfold.”
He said the bureau would now focus on its long-range forecasts.
“There’s still some very parched areas of the country so the next few months is crucial,” Dr Braganza said.
Is humanity doomed? If in 2030 we have not reduced emissions in a way that means we stay under say 2℃ (I’ve frankly given up on 1.5℃), are we doomed then?
Thongden Studio/Shutterstock
Author
Robert McLachlan is Professor in Applied Mathematics, Massey University.
Climate Explained
Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre.
Humanity is not doomed, not now or even in a worst-case scenario in 2030.
But avoiding doom — either the end or widespread collapse of civilisation — is setting a pretty low bar.
We can aim much higher than that without shying away from reality.It’s right to focus on global warming of
1.5℃ and 2℃ in the first instance.
The many manifestations of climate
change — including heat waves, droughts, water stress, more intense
storms, wildfires, mass extinction and warming oceans — all get
progressively worse as the temperature rises.
Climate scientist Michael Mann uses the metaphor of walking into an increasingly dense minefield.
As I have been pointing out for some time, climate change isn't a cliff we go off at 1.5C or 2C. It's much more like a minefield we're stepping out on to:https://t.co/2jbekKx1oG
The global average temperature is currently about 1.2℃
higher than what it was at the time of the Industrial Revolution, some
250 years ago. We are already witnessing localised impacts, including
the widespread coral bleaching on Australia’s Great Barrier Reef.
This graph shows different emission pathways and when the world is expected to reach global average temperatures of 1.5℃ or 2℃ above pre-industrial levels. Global Carbon Project, Author provided
First, it’s possible technically and economically. For example, the use of wind and solar power has grown exponentially in the past decade, and their prices have plummeted to the point where they are now among the cheapest
sources of electricity. Some areas, including energy storage and
industrial processes such as steel and cement manufacture, still need
further research and a drop in price (or higher carbon prices).
Second, it’s possible politically. Partly in response to the Paris Agreement, a growing number of countries have adopted stronger targets. Twenty countries and regions (including New Zealand and the European Union) are now targeting net zero emissions by 2050 or earlier.
A recent example of striking progress comes from Ireland – a country
with a similar emissions profile to New Zealand. The incoming
coalition’s “programme for government” includes emission cuts of 7% per year and a reduction by half by 2030.
There is also a growing understanding that to ensure a safe future we
need to consume less overall. If these trends continue, then I believe
we can still stay below 1.5℃.
The pessimist perspective
Now suppose we don’t manage that. It’s 2030 and emissions have only
fallen a little bit. We’re staring at 2℃ in the second half of the
century.
At 2℃ of warming, we could expect to lose more than 90% of our coral
reefs. Insects and plants would be at higher risk of extinction, and the
number of dangerously hot days would increase rapidly.
The challenges would be exacerbated and we would have new issues to consider. First, under the “shifting baseline”
phenomenon — essentially a failure to notice slow change and to value
what is already lost — people might discount the damage already done.
Continuously worsening conditions might become the new normal.
Second, climate impacts such as mass migration could lead to a rise
of nationalism and make international cooperation harder. And third, we
could begin to pass unpredictable “tipping points”
in the Earth system. For example, warming of more than 2°C could set
off widespread melting in Antarctica, which in turn would contribute to
sea level rise.
But true doom-mongers tend to assume a worst-case scenario on
virtually every area of uncertainty. It is important to remember that
such scenarios are not very likely.
While bad, this 2030 scenario doesn’t add up to doom — and it
certainly doesn’t change the need to move away from fossil fuels to
low-carbon options.
