Climate change is multiplying existing threats to much of the natural world, and more species face an unparalleled extinction risk.
Africa's lions number only 10% of those the continent could sustain. Image: Luca Galuzzi via Wikimedia Commons
Biologists have once again confirmed that
the wild things face a growing extinction risk, and that the biggest
losers could be humankind itself.
They point out that at a conservative
estimate the economic benefits of biodiversity – the collective word for
all the richness of the planet's species – are at least 10 times the
cost of conservation of that biodiversity.
And yet, they report, human actions
already threaten a quarter of all mammal species and 13% of all birds.
An estimated 21,000 plants and other kinds of animal are known to be at
risk.
In one of the world's richest habitats of
all – the terrain where south-east Asia, India and China meet – people
in the last 50 years have put at risk two thirds of all mammals that
weigh more than 10kg.
This summary of waste and despoliation is in a series of papers in the journal Nature, one of which looks again at the threats to biodiversity, while another concentrates on the ways people influence and depend on the fruits of three billion years of natural evolution.
Human pressure
It is a given that human economies depend
entirely on what grows on the planet, and what can be excavated from
its soils. The clearing of the forests and the settlement of the
grasslands, pollution from the cities, overhunting and overgrazing, all
driven by the swelling of human numbers, have now taken rates of species
extinction to alarming levels.
Climate change, too, has now become a factor: it has been linked to the potential extinction of species, and to the obliteration of species in particular regions.
It has also been identified as a danger to the diversity of plant life as
temperatures rise and rainfall patterns change with rising ratios of
atmospheric carbon dioxide, the greenhouse gas emitted from internal
combustion engines and coal-fired power stations.
No one yet claims that climate change itself is the principal hazard, but it exacerbates the impact of all the other pressures on wildlife.
Tropical targets
So a team led by David Tilman of the University of Minnesota
has delivered a paper looking at the next 50 years, as human impact on
habitat poses, they say "unprecedented levels of extinction risk on many
more species worldwide" – especially the large mammals of tropical
Africa, Asia and South America.
The world had lost half of its
terrestrial mammalian megafauna – mammals heavier than 44kg – by 1,000
BC, and 15% of all bird species. In the last 3,000 years human numbers
have multiplied 25-fold and another 4bn of us will join the human race
by the century's end. So, the scientists argue, unless steps are taken,
extinction rates will accelerate.
But, they point out, some steps are being
taken: 31 bird species have been saved by conservation programmes from
total extinction, and the same efforts have halted the decline of one
threatened vertebrate in five. Captive breeding programmes have
reintroduced species that were once all but lost.
But there is much more to be done: lion numbers in Africa, for instance, have fallen to one-tenth of their potential.
And in a second paper, a team led by Forest Isbell of the University of Minnesota and backed by co-authors from eight nations on four continents, instances the benefits of conservation.
"Human activities are driving the sixth mass extinction in the history of life on Earth, despite the fact that diversity of life enhances many benefits people reap from nature"
Biodiversity in the form of trees and scrubland saves humans up to US$3 trillion just as carbon storage: that is, it keeps dangerous levels of carbon out of the atmosphere.
At a practical finance level, the
calculated value of biodiversity to commercial forest productivity is
set at between $166bn a year and $490bn.
Right now, the world spends about $25bn a
year on conservation. It would cost $76bn annually to meet all the
world's conservation targets. And, the authors point out, a cash value
simply cannot be set on many of biodiversity's blessings. Some things
are priceless.
"Human activities are driving the sixth
mass extinction in the history of life on Earth, despite the fact that
diversity of life enhances many benefits people reap from nature, such
as wood from forests, livestock forage from grasslands, and fish from
oceans and streams," said Dr Isbell. "It would be wise to invest much
more in conserving biodiversity."
*Tim Radford, a founding editor of Climate News Network, worked for The Guardian for 32 years, for most of that time as science editor. He has been covering climate change since 1988. Links
Plastic pollution and overfishing may currently be in the headlines. But
rising CO2 emissions are also a key threat to the ocean that covers 71
percent of the planet, and a major challenge for future life on Earth.
Frank Bainimarama knows all about the need to protect the ocean. As
the prime minister of Fiji, he runs a country made up of more than 300
islands in the South Pacific. This week, he's been co-hosting the first
ever UN conference on the ocean in New York, along with Sweden's Climate
Minister Isabella Lovin, focusing on sustainable development and
conservation of the world's oceans, seas and marine resources.
Speaking
to the assembled leaders from government, science, business and civil
society, Bainimarama - also the incoming president of this year's UN
Climate Conference in November - made it clear that ocean protection and
climate change are inextricably linked.
"Climate change poses
the biggest threat the world has ever known," he said. "And the quality
of our oceans and seas is also deteriorating at an alarming rate. They
are interlinked, because rising sea levels, as well as ocean acidity and
warmer waters, have a direct effect on our reefs and fish stocks and
the prosperity of our coastal communities."
Fiji's prime minister (left) was in Berlin for climate talks in May.
In hot water 2016 was not only the warmest year on
record, as far as our planet's atmospheric temperature is concerned. In
its "Statement on the State of the Global Climate 2016," published
earlier this year, the World Meteorological Organization (WMO) confirmed
that globally averaged sea-surface temperatures had also hit record
levels.
Scientists were surprised at the speed at which sea
temperatures have risen. In the last century, the 15 years with the
highest ocean heat anomalies have all been within the last two decades,
according to data from the United States' National Centers for
Environmental Information (NCEI). And the WMO report predicts that the
trend will continue.
"The extra carbon dioxide that gets released
into the atmosphere through our fossil fuels and deforestation is
associated with extra heat," explained Susan Avery, an atmospheric
physicist and president emerita of the renowned Woods Hole Oceanographic
Institution, in an interview with DW last October. "And 93 percent of the extra warming is actually in the ocean."
Earlier this year, Avery became the first climate scientist to join the board of ExxonMobil. Migrants and aliens
Warming
seas play havoc with the organisms that live there, completely changing
their living conditions to the extent where some are no longer able to
survive in their traditional habitat. Mojib Latif, head of research on
ocean circulation and climate dynamics at the Geomar Helmholtz Centre
for Ocean Research in Kiel, told DW that the ocean isn't just warming on
the surface, but down to a depth of 2,000 meters (around 6,500 feet),
"a giant volume."
That heat will still be present - and will
slowly escape from the ocean - for centuries to come. "This is basically
why global warming will continue even if we don't really emit any
greenhouse gases any longer," he said.
Atlantic cod are moving further north into Arctic waters.
Fish species are moving toward the poles in search of cooler water, and alien species are moving in to replace the traditional residents in warming waters.
Coral
reefs are perhaps the best-known victims of ocean warming. They are
frequently in the headlines, most notably Australia's famous Great
Barrier Reef, which has been devastated by bleaching.
"Corals
don't have very great temperature tolerance. So if the oceans warm by
more then 1.5 degrees [Celsius] or so, they would probably die," said
Latif. "And it's well possible that without climate protection, all
tropical corals will be gone by the middle of the century."
Extreme weather
Warming
seas are also influencing the world's weather patterns, and scientists
are expecting increases in extreme weather events.
The El Nino weather event, a natural cycle, illustrates what happens when the ocean warms.
Some have attributed the extreme rainfall and flooding in Peru earlier this year to warming seas.
"El Ninos are events that are characterized by enormously high sea
surface temperatures," said Latif. He attributed the extreme rainfall
and flooding in Peru earlier this year to extremely warm water off the
coast. "Sea temperatures off Peru are slowly warming."
The question is whether global change is having an influence on the climate of South America.
"What
we can say is that El Ninos have become more frequent during the recent
decades and they have somehow became stronger during the last 20
years," said Latif.
"Whether this is already a trend or not is
hard to say, but some climate models actually project that this is
exactly what's going to happen in response to climate change."
Warmer water, rising seas
Recent
research shows sea levels are rising almost three times as fast as they
were 25 years ago. Experts say ocean warming has been responsible for
about half the sea level rise that we have observed during the last
century, as warmer water expands.
The other key factor is melting
ice, as the world warms. The Intergovernmental Panel on Climate Change
(IPCC) is working on a special report on the ocean and climate change,
to be finalized in September 2019. It will include information on ice
melt in Greenland and in the Antarctic, including the East Antarctic,
long thought to be immune to global warming.
Greenland's massive ice sheet is melting faster than ever.
Hans Pörtner, of Germany's polar and marine research center the
Alfred Wegener Institute, is co-chair of an IPCC working group which
focuses on impacts, vulnerabilities and adaptation possibilities for
humans under climate change. He views this area as one of most
challenging.
"We have increased awareness that previous estimates
of sea level rise have been too conservative," he told DW. Looking back
at the Earth's history, he said, "we know that during the last
interglacial period, with 0.7 to 2 degrees global warming above
pre-Industrial levels - these are the comparable numbers to where we are
today - we had a sea level of around 7 meters [about 23 feet] higher.
And if we compare and look back at the last period in Earth's history
where we had 400 parts per million CO2 - and that's also where we are
now - we had a similar degree of higher sea level."
So far, however, countries have based their adaptation and coastal protection measures on earlier, more conservative estimates.
"They
will have to increase their ambition in coastal protection. And in
several examples, we will have to give land back to the oceans. We may
not be able to protect the land because sea level may actually reach
2 meters or even more by the end of the century," Pörtner said.
Upsetting the conveyor belt
The influx of melting ice doesn't just lead to rising sea levels, as atmospheric physicist Susan Avery explained.
"When
the land-based ice comes into the ocean, you get a freshening of
certain parts of the ocean, so particularly the sub-polar North
Atlantic. So you have a potential for interfacing with our normal
thermohaline circulation systems, which could dramatically change that,"
she said. "The changes in salinity are beginning to be noticed, and
changes in salinity are a signal that the water cycle is becoming more
vigorous."
Scientists describe these systems as the "global
conveyor belt" that links the oceans of the world and in turn influences
climate. One example is the Gulf Stream system, which is to a large extent responsible for the temperate climate of Europe and parts of North America.
A study released this week in the Proceedings of the National Academy of Sciences in
the US suggests that if the ice influx increases far enough, the
disruption of the ocean current system could also have devastating
consequences in Africa, with a disruption in rainfall patterns playing
havoc with agriculture.
Atlantis 2.0: What happens when ocean temperatures rise? As global warming speeds up, so does the rise in sea levels. While 2004 to 2010 saw oceans rise by about 15 millimeters in total, this value doubled for 2010 to 2016. Tropical regions in the western Pacific are especially affected, threatening many of the coastal areas and low-lying islands with submersion by the end of the century.
An acid bath?
Alongside the extra heat, the CO2 we have indirectly been dumping into the ocean has another devastating impact.
"The
extra carbon dioxide, when it gets dissolved into the ocean, through
various simple chemical equations, will increase the PH or acidification
in the ocean," Avery explained. Seawater is already at least 26 percent
more acidic than it was before the onset of the Industrial Revolution
in the 19th century, according to the "State of the Ocean" report
published by the International Programme on the State of the Ocean back
in 2013. The report found the ocean could be 170 percent more acidic by
the end of the century.
Mesocosms, closed environments, are used for ocean acidification experiments in nature.
Over the last 20 years, scientists around the world have been
conducting laboratory experiments to find out what that would mean for
the flora and fauna of the ocean. Ulf Riebesell, a professor of
biological oceanography at Geomar, conducted the world's first
experiments in nature off the coast of the Norwegian archipelago of
Svalbard in 2010.
The on-site experiments showed that increasing
acidification decreases the amount of calcium carbonate in seawater,
making life very difficult for sea creatures that use it to form their
skeletons or shells. This change will affect coral, mussels, snails, sea
urchins and starfish, as well as fish and other organisms, Riebesell
told DW.
"Some of these species will simply not be able to compete with others in the ocean of the future," he said.
That
could have severe economic and social consequences, as acidification
ultimately affects the food chain. Riebesell pointed out that coral
reefs, for instance, are home to numerous species, serve as nurseries
for fish, attract tourists and protect coastlines against waves and
storms.
Riebesell has headed the German projectBIOACID (Biological
Impacts of Ocean Acidification) for the last eight years. It's expected
to publish a summary of its results ahead of the UN climate conference
in Bonn in November.
Hot problem for cold water
Polar areas are
most affected by ocean acidification, as cold water is able to more
quickly absorb CO2. Experiments in the Arctic, which is already warming
around twice as fast as the global average, indicate that the seawater
there could become corrosive within a few decades, Riebesell said. "That
means the shells and skeletons of some sea creatures would simply
dissolve."
At a working meeting of the BIOACID group in Kiel last
week, IPCC co-chair Hans Pörtner told DW that ocean acidification, a
relatively young research field, had already made its way into the
policy arena.
"It's being considered as one of the climate
challenges for the ocean, and it's also considered in the context of
sustainable food supply, especially for developing countries," he said.
But
even countries like the United States are already feeling the effect,
said Pörtner. On the country's west coast, ocean acidification is
already threatening oyster cultures, and he said this economic impact
has increased awareness of the problem.
Scientists are also
concerned that the increasing amount of CO2 being stored in the ocean
could, in turn, create a feedback effect that could further exacerbate
global warming.
In the long run, the ocean will become the biggest sink for human-produced CO2, but it will absorb it at a slower rate.
"Its buffer capacity will decrease, the more acidic the ocean becomes," said Riebesell.
Science and policy
Pörtner
told DW that the writing is on the wall. "We really have to go into
ambitious mitigation, if we want to have a chance to keep this under
control."
Carol Turley, senior scientist at the Plymouth Marine
Laboratory in the UK, is highlighting the issue of ocean acidification
at the UN conference in New York this week. She told DW that a
combination of local management measures and global action were
necessary to protect the ocean and implement the UN's sustainable
development goals.
"Although acidification, warming, sea level
rise and oxygen loss represent global challenges requiring international
agreements, there are varied options for reducing other stressors while
efforts continue to reduce emissions of carbon dioxide to the
atmosphere," she said.
Turley said it was "inspiring" that
UN Secretary-General Antonio Guterres and the co-chairs of the ocean
conference, Fiji and Sweden, had recognized the key role of
climate-related ocean stressors, including ocean acidification, and
that the combined impact of these may threaten the implementation of the
UN's Sustainable Development Goal 14 (SDG 14), which focuses on the
ocean and life below water.
She said it was also heartening to
hear their messages of hope. "It's not too late to fix the ocean. This
shows how the evidence from science has been taken up by policy makers,"
she said.
Carol Turley of the Plymouth Marine Laboratory has been highlighting the issue of ocean acidification in New York this week.
'Stay optimistic'
Martina Stiasny, a young
climate scientist from the Geomar Helmholtz Centre for Ocean Research in
Kiel, Germany, told conference participants in New York about her
research on how climate change-induced ocean acidification is affecting
fisheries.
"We are already starting to see the first effects in
the oceans," she told DW. "It's imperative that we start to act now.
Otherwise it poses a serious threat to the health of the marine
ecosystems and food security. It's not only important for the SDG 14,
but also links to most other SDGs in terms of human health, fighting
hunger and poverty and most other goals."
The landmark ocean
conference has been taking place against the background of US President
Donald Trump's decision to take the US out of the 2015 Paris climate
agreement, a move Stiasny describes as a "major disappointment."
But she takes heart from the widespread movement to press ahead with emissions reductions and a transition to renewable energy.
"The
statement that America made by pulling out is of course the wrong
message to send to the world," she said. "But fighting climate change is
done every day by everyone on this planet and I believe we have no
choice but to stay optimistic."
Chief scientist’s report flies in the face of previous recommendations on reducing electricity emissions
The report by the chief scientist, Alan Finkel, has modelled a clean
energy target that would reduce electricity emissions by 28% on 2005
levels.
Photograph: David Crosling/AAP
Less than two weeks ago, Alan Finkel told the Senate his landmark
report would help Australia meet the commitments it made in Paris to
reduce its economy-wide emissions by 28% below 2005 levels by 2030.
But his recommendations on the future of the National Electricity Market, released today, appear to fly in the face of those very commitments.
Before Senate estimates Finkel said: “We are very cognisant of the
commitment that the nation has made through the Paris accords.
“We absolutely need to deal with the issue of ensuring that the
electricity sector can do its fair share in helping the nation to meet
its obligations under the Paris accord – the COP21 accord.”
Now today, his landmark review of the National Electricity Market has
modelled cuts to emissions of the electricity sector that are the same
as what the entire economy needs to do: 28% below 2005 levels by 2050.
He said anything deeper, which had been suggested in other reports,
would cause problems.
Finkel suggested those cuts should be achieved with a “clean energy target” – which is equivalent to what has been called a Low Emissions Target. The result by 2030 will be one where renewables are responsible for just 42% of electricity generation.
But what is the electricity sector’s fair share?
Well it’s a lot more than that recommended by Finkel’s report.
How do we know it needs to be higher? We can look at a report from the Climate Change Authority, that Finkel himself co-wrote, that examined how much the electricity sector needed to do.
After examining several scenarios for meeting Australia’s emissions
reduction targets, it concluded: “The common finding is that the
electricity sector can contribute deep, cost-effective emissions
reductions as part of national action to meet global temperature goals.”
The electricity sector has to do much of the heavy lifting for several reasons.
it’s the biggest source of carbon emissions – producing more than a third of the country’s total.
many other industries can’t easily reduce emissions – it’s very hard
to reduce the emissions from the agriculture sector, for example.
decarbonising the electricity sector will help other sectors
decarbonise – for example, if cars stop using petrol and shift to
electricity, we will need the electricity system to be low-emissions in
order to see an actual reduction in emissions.
That last point was made by the Climate Change Authority report.
“Substantial decarbonisation of electricity supply can facilitate
emissions reductions in other sectors, as electricity can displace their
direct use of fossil fuels,” it said.
But in his report today, Finkel said any deeper cuts could be
problematic. “The adoption of a more ambitious target would have larger
consequences for energy security as such a target would likely see a
higher level of [variable renewable energy] incentivised,” Finkel wrote.
Bill Hare, the a leading climate scientist and CEO at Climate Analytics has spent a lot of time modelling precisely this issue
“From a scientific perspective this is quite shocking because the
almost universal consensus from the modelling exercises for how to
achieve the Paris agreement has the power sector doing a lot more than
the rest of the economy everywhere in the world,” Hare said.
This conclusion appears to have been crafted to fit with the politics of the present government. Bill Hare, climate scientist
“I think this conclusion appears to have been crafted to fit with the
politics of the present government rather than the science and
understanding of these systems,” he said.
Hare said he doesn’t know of any work globally that supports Finkel’s
claim that deeper cuts to emissions will put the system’s reliability
or security at risk.
Dylan McConnell from Melbourne University said an additional problem
with having shallow cuts in emissions in the electricity sector, was
that it was the cheapest place to make the cuts – so the overall cost to
the economy of meeting our Paris commitments will be more expensive.
How deep do emissions cuts need to be in the electricity sector?
Finkel’s report for the Climate Change Authority can help us answer that. The report found
the electricity sector’s emissions intensity should drop by about 69%
between 2015 and 2030. (From 0.81 tonnes per megawatt hour in 2015 to
0.25 tonnes by 2030.)
According to their modelling
of a Clean Energy Target making this cut, they found it would reduce
total emissions from the electricity sector by more than 60% from 2015
levels.
(While Paris commitments are made with reference to 2005 levels, when
total national emissions were much higher, emissions from the
electricity sector, were roughly similar in 2005 and 2015.)
So, far from Finkel’s recommendation actually getting the electricity
sector to do it’s fair share, if implemented, it would guarantee
Australia does not meet its targets made in Paris, since it is about
half as demanding on the electricity sector as it needs to be.
McConnell said there is no evidence that deeper cuts will cause problems for the security or reliability of the system – and modelling from the Australian Energy Market Operator has demonstrated that.
A way forward
It
seems likely that the weak recommendations made by Finkel were intended
to give something palatable to a Coalition government containing a conservative rump that wants state-subsidised fossil fuel generation, seemingly just for the sake of it.
But as things stand, Australia doesn’t have an emissions reduction
policy. In fact, Australia has emission growth policies, with the
government’s own projections demonstrating current policies will cause carbon emissions to grow for decades.
A mechanism like the one Finkel proposed will at least cut emissions,
even if by an amount that will still lead to catastrophic climate
change.
But more hopefully, if it is implemented in the right way, it could be “ratcheted up” by future governments
For example, if the 28% target is not legislated, but rather left as a
regulatory leaver, it is something that could be increased later. To
maintain confidence among investors looking to build energy
infrastructure, it would help if the legislation required the target to
move in only one direction (up).
Others have lined up to criticise Finkel’s recommendations on
how to deal with the variability of some renewable sources, as their
penetration increases.
Finkel has proposed a “generator reliability obligation” which would
set a minimum level of dispatchable generation in a region, and when
that threshold is crossed, all new generators would be required to be
paired with some dispatchable power – batteries, other storage, or gas
that can be switched on quickly.
Hugh Saddler from the Australian National University says that’s a badly designed mechanism.
“If implemented, this recommendation would seem certain to greatly
complicate, slow-down and add to the administrative overhead cost of
building new renewable generation. It would involve putting together a
consortium of multiple parties with potential differing objectives and
who would otherwise be competing with each other in the wholesale
electricity market,” Saddler said.
He
said that instead, a separate market mechanism should be created to
incentivise dispatchable generation. “The would be far more economically
efficient, and thus less costly to electricity consumers, than the
messy processes required under the Report’s obligation approach.”
Consumer advocates at the Public Interest Advocacy Centre (Piac) also
criticised Finkel’s approach. “Requiring new renewable energy operators
to invest in energy storage technologies or come up with other ways of
addressing their variable output is expensive and unnecessary,” Craig
Memery, team leader at Piac’s energy and water consumers’ advocacy
program, said.
“Requiring new renewable energy operators to invest in energy storage
technologies or come up with other ways of addressing their variable
output is expensive and unnecessary,” Memery said.
This particular recommendation was endorsed by the coal industry, though.
The chief executive of the Minerals Council of Australia, Brendan
Pearson, said: “The minerals sector also welcomes the concept of
Generator Reliability Obligations and Energy
Security Obligations. These could provide an important means of
ensuring that new generation can provide reliable and secure power.”
