MONACO, Sept 25, 2019 (BSS/AFP) – Two days after a climate summit failed
to deliver game-changing pledges to slash carbon emissions, the United
Nations warned Wednesday that global warming is devastating oceans and
Earth’s frozen spaces in ways that directly threaten a large slice of
humanity.
Crumbling ice sheets, rising seas, melting glaciers, ocean dead zones,
toxic algae blooms — a raft of impacts on sea and ice are decimating fish
stocks, destroying renewable sources of fresh water, and incubating
superstorms that will ravage some megacities every year, according to a
landmark assessment approved by the 195-nation Intergovernmental Panel on
Climate Change (IPCC).
Some of these impacts are irreversible.
The report, a digest of 7,000 peer-reviewed studies, is a sobering
reminder that record greenhouse gas emissions, mostly from burning fossil
fuels, are driving the planet towards a hothouse climate our species could
find intolerate.
But it also raises more clearly than ever before a red flag on the need to
confront changes that can no longer be averted.
For some island nations and coastal cities, that will almost certainly
mean finding new places to call home.
– Crumbling ice sheets –
“Even if we manage to limit global warming, we will continue to see major
changes in the oceans,” said Valerie Masson-Delmotte, a researcher at the
Laboratory for Climate and Environmental Sciences and an IPCC co-chair.
“But it will at least buy us some time, both for future impacts and to
adapt.”
The underlying 900-page scientific report is the fourth such UN tome in
less than a year, with others focused on a 1.5-Celsius cap on global warming,
the decline of biodiversity, as well as land use and the global food system.
All four conclude that humanity must overhaul how it produces, distributes
and consumes almost everything to avoid the worst ravages of global warming
and environmental degradation.
By absorbing a quarter of manmade CO2 and soaking up more than 90 percent
of the heat generated by greenhouse gases, oceans have kept the planet
livable — but at a terrible cost, the report finds.
Seas have grown acidic, potentially undermining their capacity to draw
down CO2; warmer surface water has expanded the force and range of deadly
tropical storms; marine heatwaves are wiping out coral reefs, which are
unlikely to survive the century.
Most threatening of all, accelerating melt-off from glaciers and
especially Earth’s ice sheets atop Greenland and Antarctica are driving sea
level rise.
– ‘A world of higher seas’ –
Since 2005, the ocean has risen 2.5 times faster than during the 20th
century. The rate at which the waterline rises will quadruple again by 2100
if carbon emissions continue unabated, the report found.
“Regardless of emissions scenarios, we face a world of higher sea levels,”
said co-author Bruce Glavovic, a professor at Massey University, New Zealand,
noting that humanity is concentrated on the world’s shorelines.
“It doesn’t take a big rise in sea level to lead to catastrophic
problems,” he added. “Sea level rise is not a slow onset problem — it’s a
crisis of extreme weather events.”
By 2050, many coastal megacities and small island nations will experience
what were formerly once-a-century weather disasters every year — even with
an aggressive drawdown of greenhouse gas emissions.
And by mid-century, more than a billion people will be living in low-lying
areas vulnerable to cyclones, large-scale flooding and other extreme weather
events amplified by rising seas.
– Hefty price tag –
Some cities, such as New York, are planning to spend tens of billions of
dollars — and probably far more — to shore up their defences.
Indeed, building dikes and levees along with other measures would reduce
the risk of flooding caused by sea level rise and storm surges over the next
80 years 100- to 1,000-fold, according to the IPCC report’s 42-page Summary
for Policy Makers.
But with a heft price tag: up to hundreds of billions of dollars a year.
For many megacities and sprawling delta cities in the developing world,
however, an engineered solution will be impractical or prohibitively
expensive.
Under the IPCC’s consensus rules, all countries must sign off on the
language of the report’s executive summary, designed to provide leaders with
objective, science-based information.
The five-day meeting in Monaco went deep into overtime when Saudi Arabia
objected what might have been a routine reference to the October 2018 IPCC
report on the feasibility of capping global warming at 1.5 degrees Celsius.
The 2015 Paris Agreement calls for capping global warming at “well below”
2 C, and 1.5 C if possible.
As a result, passages in the final draft were scrubbed, including one
estimate that humanity’s “carbon budget” — the amount of CO2 we can emit
without breaching a temperature barrier — for a 1.5 C world could be as
short as eight years, according to a copy seen by AFP.
Earth’s temperature has so far risen 1 C above pre-industrial levels.