Warm waters are pooling underneath Antarctic glaciers in a way that’s causing glaciers to melt more rapidly and preventing the formation of cool water beneath Antarctica, according to a new study.
This could slow ocean currents and potentially lead to a rapid sea-level rise event known as a pulse.
Such an event could be devastating, causing sea levels to rise by more than 10 feet by the end of the century.
The worst-case climate scenario for coastal cities is known as a “pulse.”
In that situation, abnormally warm water could cause the glaciers
that hold back ice sheets on top of Antarctica and Greenland to
collapse. That would cause massive quantities of ice to pour into the
world’s oceans, which could lead to extremely rapid sea-level rise
around the world.
If such a scenario were to occur, current sea-level rise predictions for vulnerable cities like Miami would be far too low.
Right now, scientists predict Miami will likely be surrounded by seas
up to 7 or 8 feet higher than they were in 1900 by the end of this
century. But in the case of a pulse, some experts think South Florida
could see 10 to 30 feet of sea-level rise by 2100.
Models predict that amount of rise could also be accompanied by superstorms.
Conditions that might mark the start of such a scenario seem to already be underway in Antarctica, according to a recent study published in the journal Science Advances.
The researchers behind the work found that in at least two Antarctic
regions where there’s been notable ice loss, glaciers are melting fast
enough to counteract a process that would normally keep the waters under
the Antarctic cool. And where warm water collects, faster melting
happens.
“Our study shows that this feedback process is not only possible but
is in fact already underway, and may drive further acceleration of the
rate of sea-level rise in the future,” Alessandro Silvano, lead author
of the study, said in a statement.
Warm water pooling below the ice
The two areas analysed in the study were the Amundsen Sea in West Antarctica and the Sabrina Coast in East Antarctica.
US Coast Guard. Chief Petty Officer David Mosley
Normally, holes in Antarctic ice
rapidly cool waters around the Antarctic continental shelf, which
prevents warm water from melting glaciers. That cooling process creates a
type of ocean water known as dense shelf water, which is so cold and
dense that it sinks, eventually forming a mass of water called Antarctic
bottom water.
But at the regions the researchers studied, water exposed at the
surface is not being cooled and sinking. Instead, warm water is kept
warm by rapidly melting glaciers, creating a mass of warm water
underneath the ice.
“This process is similar to what happens when you put oil and water
in a container, with the oil floating on top because it’s lighter and
less dense,” Silvano said. “We found that in this way increased glacial
meltwater can cause a positive feedback, driving further melt of ice
shelves and hence an increase in sea level rise.”
That means warm water is melting glaciers from below.
From what researchers can tell, a similar melting process may have
triggered a sea-level rise of 16 feet at the end of the last glacial
period.
A series of concerning events
The pooling of warm water beneath Antarctic glaciers makes rapid
glacier melt more likely, which increases the possibility of ice shelf
collapse and rapid sea-level rise.
At the same time, Antarctic bottom water helps drive the global
currents, which enable the ocean to absorb heat and carbon dioxide. A
lack of Antarctic bottom water could therefore slow ocean currents, and
slower currents are associated with more superstorms, according to the historical record and computer models.
Global annual temperature and CO2 levels, 1959-2016
Source: Environmental Protection Agency; NOAA
This slowing would also cause warming to happen more rapidly in Earth’s atmosphere – further accelerating glacier melt.
“In combination, the two processes we identified feed off each other to further accelerate climate change,” Silvano said.
As the researchers explain in the study, there’s still a lot to learn
about this process and its connection to climate change. But they said
what we’re seeing now is further evidence that stopping the rise of
global temperatures is essential.
The burning of fossil fuels is causing Earth’s temperature to creep
higher and higher above pre-industrial levels. The higher the
temperature gets, the more likely the collapse of ice shelves becomes –
as well as the potential pulse that comes with it.
When the improper disposal of wastewater
from the construction site of a joint shopping center and apartment
complex threatened to contaminate hundreds of residents’ water in
Sonsonate, El Salvador, activists and community leaders filed a lawsuit
through the country’s specialized environmental justice system.
In
response, Lina Pohl, El Salvador’s minister of environment and natural
resources, went to inspect the water. When she found signs of
contamination, she ordered the suspension of construction.
Using legal tools to report an alleged
violation of the law might not seem groundbreaking. But in El Salvador,
justice in environmental disputes has long swung in favor of rich
developers with political connections rather than activists and
citizens.
So, in 2014 the Central American nation established three
regional environmental tribunals to even the playing field in environmental disputes.
“Historically, institutions in El Salvador
have operated with lots of corruption. This is a system that breaks
with that tradition of corruption,” says Salvador Recinos, specialist in
ecological policy for the Salvadoran Ecological Unit (UNES),
a non-governmental organization based in San Salvador.
“With this court
system, there is clearly a better chance of people in El Salvador
having access to justice in these types of environmental cases.”
More than 40 countries around the world have established environmental court systems. Map by Sean Quinn.
Justice systems around the world face
obstacles to settling environmental cases quickly and fairly, whether
from corruption, drawn-out trials or judges who lack understanding of
environmental issues. Specialized environmental courts have emerged as
an important defense against human-caused destruction of the
environment. In 2009 there were only 350 of these specialized court
systems in the world. Today there are at least 1,200 in 44 countries.
Evolving Understanding
The boom in environmental courts is driven
by an evolving understanding of human rights and environmental law,
increased awareness of the threats of climate change, and
dissatisfaction with general court systems, according to George (Rock)
Pring, co-author of “Environmental Courts & Tribunals,” a United Nations Environment Programme (UNEP) guide for policy-makers.
“Human rights and environmental rights are
now seen as overlapping and complementing each other, not
surprisingly,” he says. “Climate change has also been a big pressure on
creating environmental courts, as have concepts such as sustainable
development.”
The Environmental Court of
Santiago, Chile, is composed of three ministers — two lawyers and one
individual with a science background. Copyright Santiago Environmental
Court
International agreements like the Paris
Climate Change Accords have made important strides in recognizing the
severity of the problems posed by climate change, but their non-binding
nature means that it is up to national court systems to ensure these
promises are carried out.
Specialized environmental justice systems
are now operating on every continent except Antarctica with a range of
responsibilities and capabilities. The goal of these specialized justice
systems is always the same: to decide cases quickly, fairly, and more
cheaply than would be the case through the conventional court system.
Specialization, the logic goes, is the way to do that.
Take India, for example. The country
suffers from intense air and water contamination, problems that have
dire consequences for the environment as well as public health. Solving
these problems is urgent, but the country of 1.3 billion people has a
court system that is notoriously slow, with some cases dragging on for more than 10 years.
In 2011, a specialized court system called the National Green Tribunal
(NGT) began operating in India. The tribunal, with multiple branches
across country, is made up of specialized environmental judges and
scientific experts.
The court can settle cases in multiple ways. In some
cases, instead of just handing down judgments, the court practices a
stakeholder consultation process, working with the activists, companies
and government institutions to come up with solutions, such as phasing
out older cars to reduce air pollution.
“Problem solving is very central to this
tribunal, and to solve the problems the court is looking beyond the
traditional remedies that are available because they want to solve the
issue rather than linger on for years to come,” says Gitanjali Gill, a
National Green Tribunal expert and professor of environmental law at the
Northumbria Law School in the U.K.
To ensure swift judgments, the tribunal is
required to solve cases in six months. Gill reports that this rule is
not strictly followed, with some cases lasting longer than six months,
but they are still resolved much faster than in India’s general justice
system.
'Green Justice': A look at China's environmental tribunals Key to Success
In Australia, the Land and Environment Court
of New South Wales has operated successfully since 1980, solving
problems of sustainable development, fighting against the effects of
climate change, and protecting the coastline and national parks.
Its longevity has given it the time to
evolve and test difference approaches, making it one of the most
innovative environmental court systems to date. One of these innovations
is the concept of the “multi-door courthouse,”
which offers different types of conflict resolution so all parties
involved can reach an agreement that is not necessarily handed down from
a judge.
Strong leadership, steady funding, and
political support have been the key pillars to the court’s success,
according to the UNEP report.
The UNEP report attributes the success of
the court to “judicial leadership, sufficient budget, comprehensive
jurisdiction, political support and stakeholder overview.
In El Salvador, trust in the justice
system is low and risk of environmental damage by climate change is
high, making the country a prime candidate for a specialized
environmental court system. Before the system launched in 2014, some
Salvadoran citizens and activists didn’t see the point in reporting
environmental violations. Without pressure from civil society,
government institutions didn’t keep on top of environmental violations.
But that’s changing.
“Now, citizens
know that there are environmental tribunals. Companies also know. So
there is a new push within the country towards recognizing the
importance of environmental laws …”
“Now, citizens know
that there are environmental tribunals. Companies also know. So there is
a new push within the country towards recognizing the importance of
environmental laws given that there is a new institutionalized system
that handles these cases,”says Samuel Lizama, presiding
judge at the Environmental Tribunal of San Salvador, one of the three
regional courts in the country’s specialized environmental court system. Far From Perfect
These specialized systems are far from
perfect. Some experts oppose them in principle, arguing that they lead
to biased judgments, that the benefits do not outweigh the costs, and
that they are a Band-Aid for a larger problem of a weak justice system,
as Pring explains.
In India, judgments are not always carried
out, and the tribunal does not have the capability or resources to
follow up on all the cases. In El Salvador, environmental judges balance
other caseloads, taking their time and energy away from environmental
cases.
In at least seven cases, including Bahamas, Netherlands and South
Africa, environmental court systems have been discontinued because of
lack of funding, change in political leadership or pressure from special
interest groups.
In addition, it’s hard to objectively
judge the value of environmental court system decisions in a world in
which environmental law evolves and climate change creates new
challenges.
“The problem is, how do you tell if
something is a good environmental judgment?” says Pring. “Ten years ago,
courts were not focusing on sustainable development or climate change
and rulings that looked good at the time are not good now. It’s hard to tell today what today’s good-looking environmental decision will look like 10 years from now.”
Environmental courts don’t provide a
one-size-fits-all approach to solving problems of governance when it
comes to environmental issues, but they have proved effective for many
countries, from El Salvador to India to Australia. They will likely
continue as an important line of defense against environmental
deterioration as the threats from climate change intensify in the coming
years.
“The Darfur conflict began as an ecological crisis”, wrote the then-UN secretary general Ban Ki-Moon
back in 2007, about an ongoing war which arose, he said, “at least in
part from climate change”. Since then the idea that climate change has
caused and will cause human conflict and mass migrations has become more
and more accepted – just look at the claimed effects of droughts in
Syria and Ethiopia.
The media has even started using terms such as “climate refugees” and
“environmental migrants” to describe people fleeing their homes from
these climate-driven conflicts. But it isn’t clear whether there is much
evidence for this link between climate change and conflict – there
certainly seems to be no consensus within the academic literature.
In our recent paper,
my student Erin Owain and I decided to test the climate-conflict
hypothesis, using East Africa as our focus. The region is already very
hot and very poor, making it especially vulnerable to climate change (in
fact neighbouring Chad is by some measures the single most vulnerable country in the world).
As the planet warms, East Africa’s seasonal rains are expected to become much more unpredictable.
This is a particular problem as recent economic development has been
concentrated in agriculture, a highly climate-sensitive sector that
accounts for more than half of the entire economy in countries like
Ethiopia or Sudan. One study led by the European Commission found that
declining rainfall over the past century may have reduced GDP across Africa by 15-40% compared with the rest of the developing world.
Chilling in North Darfur.Albert Gonzalez Farran, UN/Flickr, CC BY-NC-ND
East Africa also has a long history of conflict and human
displacement, which persists in some countries to this day, such as the
civil wars in Sudan and Somalia. The UN Refugee Agency reports there were more than 20m displaced people in Africa in 2016 – a third of the world’s total. The World Bank predicts this could rise up to 86m by 2050 due to climate change.
Is it really because of climate change?
Lower levels of conflict are associated with economic growth and stable politics.Owain and Maslin, 2018, Author provided
To test the climate-conflict hypothesis, Erin and I therefore focused on the ten main countries in East Africa. We used a new database
that records major episodes of political violence and number of total
displaced people for the past 50 years for each of the ten countries. We
then statistically compared these records both at a country and a
regional level with the appropriate climatic, economic and political
indicators.
We found that climate variations such as regional drought and global
temperature did not significantly impact the level of regional conflict
or the number of total displaced people. The major driving forces on
conflict were rapid population growth, reduced or negative economic
growth and instability of political regimes. Numbers of total displaced
people were linked to rapid population growth and low or stagnating
economic growth.
The evidence from East Africa is that no single factor can fully
explain conflict and the displacement of people. Instead, conflict seems
to be linked primarily to long-term population growth, short-term
economic recessions and extreme political instability. Halvard Buhaug, a
professor at the Peace Research Institute Oslo, looked at the same
questions in 2015 and his study reached much the same conclusion: sociopolitical factors were more important than climate change.
Fetching water in Ethiopia, 2016.Melih Cevdet Teksen/Shutterstock
But refugees are linked to climate change
Things were different for “refugees”, however – those displaced
people who were forced to cross borders between countries. Refugee
numbers were related to the usual demographic and socio-economic
factors. But in contrast to total displaced people and occurrence of
conflict, variations in refugee numbers were found to be related
significantly to the incidence of severe regional droughts. And these
droughts can in turn be linked to a long-term drying trend ascribed to anthropogenic climate change.
As droughts have become more severe, refugee numbers have increased.Owain and Maslin, 2018, Author provided
However, it is important to consider the counterfactual: had there
been slower population growth, stronger economies and more stable
political regimes, would these droughts still have led to more refugees?
That’s beyond the scope of our study, which may not be a definitive
test of the links between climate change and conflict. But the
occurrence of peaks in both conflict and displaced people in the 1980s
and 1990s across East Africa suggest that decolonisation and the end of the Cold War could have been key issues.
Nonetheless, while conflict has decreased across the region since the
end of the Cold War, the number of displaced people remains high. We
argue that with good stable governance there is no reason why climate
change should lead to greater conflict or displacement of people,
despite the World Bank’s dire predictions. Water provides one reason to
be optimistic. The UN reports
that, over the past 50 years, there have been 150 international water
resource treaties signed compared to 37 disputes that involved violence.
What our study suggests is the failure of political systems is the
primary cause of conflict and displacement of large numbers of people.
We also demonstrate that within socially and geopolitically fragile
systems, climate change may potentially exacerbate the situation
particularly with regards to enforced migration.
