https://www.afp.com/en/news/826/draft-un-report-warns-rising-seas-storm-surges-melting-permafrost-doc-1jt79t3
[images in online article]
Draft UN report warns of rising seas, storm surges, melting permafrost
30 Aug 2019
The same oceans that nourished human evolution are poised to unleash
misery on a global scale unless the carbon pollution destabilising
Earth's marine environment is brought to heel, warns a draft UN report
obtained by AFP.
Destructive changes already set in motion -- some irreversible -- could
see a steady decline in fish stocks, a hundred-fold or more increase in
the damages caused by superstorms, and hundreds of millions of people
displaced by rising seas, according to the Intergovernmental Panel on
Climate Change (IPCC) "special report" on oceans and Earth's frozen
zones, known as the cryosphere.
As the 21st century unfolds, melting glaciers will first give too much
and then too little to billions who depend on them for fresh water, it
finds.
Without deep cuts to manmade emissions, at least 30 percent of the
northern hemisphere's surface permafrost could melt by century's end,
unleashing billions of tonnes of carbon and accelerating global warming
even more.
The 900-page scientific assessment is the fourth such tome from the UN
in less than a year, with others focused on a 1.5-Celsius
(2.6-Farenheit) cap on global warming, the state of biodiversity, and
how to manage forests and the global food system.
All four conclude that humanity must overhaul the way it produces and
consumes almost everything to avoid the worst ravages of climate change
and environmental degradation.
Governments meet in Monaco next month to vet the new report's official
summary. While the underlying science -- drawn from thousands of
peer-reviewed studies -- cannot be modified, diplomats with scientists
at their elbow will tussle over how to frame the findings, and what to
leave in or out.
The final advice to policymakers will be released on September 25, too
late to be considered by world leaders gathering two days earlier for a
summit convened by UN Secretary-General Antonio Guterres to extract
stronger national commitments in confronting the climate crisis.
Guterres may be disappointed by what the world's major greenhouse gas
emitters put on the table, according to experts tracking climate
politics in China, the United States, the European Union and India.
The Big Four -- accounting for nearly 60 percent of global fossil
fuel-based emissions -- all face devastating ocean- and ice-related
impacts, but none seem prepared just yet to announce more ambitious
goals for purging carbon from their economies.
- 'Irreversible' change -
Donald Trump -- a no-show at the G7 climate segment this week -- wants
the US to exit the Paris Agreement and has taken a chainsaw to
predecessor Barack Obama's climate policies.
India is rapidly developing solar power, but continues to build up
coal-fired capacity at the same time.
The European Union is inching toward a mid-century "net zero" emissions
goal, but several member states are dragging their feet.
Long seen as a leader on climate, China -- which emits nearly as much
CO2 as the US, EU and India combined -- is also sending mixed signals.
"The eyes of Beijing are gradually moving away from environmental
issues, and climate change in particular," noted Greenpeace
International analyst Li Shuo, a longtime observer of China's climate
policy.
A resurgence of domestic coal-fired power and a relaxing of air
pollution regulations, he said, point to a preoccupation with China's
slowing economy and its trade war with the US.
And yet, all of these nations face many of the threats outlined in the
IPCC report.
Shanghai, Ningbo, Taizhou and another half-dozen major coastal cities in
China, for example, are highly vulnerable to future sea level rise,
which is projected to add a metre by 2100 compared to the late 20th
century global watermark, if CO2 emissions continue unabated. Mumbai and
other coastal Indian cities are in harm's way as well.
Even in the United States, where billions are being spent to protect New
York, Miami and other exposed cities, such efforts could easily be
overwhelmed, say experts.
"There is a pervasive thread in the US right now promoted by
techno-optimists who think we can engineer our way out of this problem,"
said Michael Mann, director of the Earth System Science Center at
Pennsylvania State University.
"But the US is not ready for a metre of sea level rise by 2100," he told
AFP.
"Just look at what happened in the wake of superstorm Sandy, Katrina, in
Houston, or Puerto Rico."
- 1,000-fold flood damage increase -
By 2050, many low-lying megacities and small island nations will
experience "extreme sea level events" every year, even under the most
optimistic emissions reduction scenarios, the report concludes.
By 2100, "annual flood damages are expected to increase by two to three
orders of magnitude," or 100 to 1,000 fold, the draft summary for
policymakers says.
Even if the world manages to cap global warming at two degrees Celsius,
the global ocean waterline will rise enough to displace more than a
quarter of a billion people.
The report indicated this could happen as soon as 2100, though some
experts think it is more likely to happen on a longer timescale.
"Even if the number is 100 or 50 million by 2100, that's still a major
disruption and a lot of human misery," said Ben Strauss, CEO and chief
scientist of Climate Central, a US based research group.
"When you consider the political instability that has been triggered by
relatively small levels of migration today, I shudder to think of the
future world when tens of millions of people are moving because the
ocean is eating their land."
Earth's average surface temperature has gone up 1C since the late 19th
century, and is on track -- at current rates of CO2 emissions -- to warm
another two or three degrees by century's end.
The Paris Agreement calls for capping global warming at "well below" 2C.
Sea level rise will accelerate rapidly moving into the 22nd century, and
"could exceed rates of several centimetres per year" -- about 100 times
more than today, according to the report.
"If we warm the planet by 2C, by 2100 we will only be at the beginning
of a runaway train ride of sea level rise," said Strauss, whose research
informs the report's conclusions.
- Marine heatwaves -
Oceans not only absorb a quarter of the CO2 we emit, they have also
soaked up more than 90 percent of the additional heat generated by
greenhouse gas emissions since 1970.
Without this marine sponge, in other words, global warming would already
have made Earth's surface intolerably hot for our species.
But these obliging gestures come at a cost: acidification is disrupting
the ocean's basic food chain, and marine heatwaves -- which have become
twice as frequent since the 1980s -- are creating vast oxygen-depleted
dead zones.
In the Tasman Sea, for example, a 2015-16 heatwave lasted for 251 days,
causing disease outbreaks and a die-off of farmed shellfish.
[More climate change headlines and links at the 10n10.ca blog
https://www.10n10.ca/e/CCC-Blog.shtml ;]
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