Forbes - Mike Scott
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| A scientist carrying out tests on a glacier in Greenland. (Photo by Joe Raedle/Getty Images) Getty Images |
Sea levels are rising even faster than
scientists had predicted and by the end of the century, the oceans could
be more than a metre higher than today if global CO2 emissions are not
controlled, a new expert analysis has concluded.
Earlier
this year, the Intergovernmental Panel on Climate Change, a body
comprising the world’s leading climate scientists, published a report on
how climate change will affect land. It highlighted how climate change
is affecting the production of food, at the same time as agriculture and
deforestation are also major contributors to climate change.
Food
production will be affected by problems ranging from desertification
and more frequent and severe droughts to floods, landslides and
heatwaves, it said.
Now the IPCC has produced a follow-up looking
at the impact on the oceans and the cryosphere – the bits of the earth
that are covered in ice. This report is no more cheerful than the last
one.
It says that our oceans, ice sheets and glaciers are absorbing
the bulk of rising temperatures and that the impacts are already
evident, from the top of the highest mountain to the bottom of the
oceans – and they are affecting everyone. Climate change makes the
oceans warmer and more acidic, while reducing the oxygen content, with
knock-on effects for everything that lives in it.
Warming
temperatures are already shrinking Arctic sea ice and the loss of ice
from Greenland and the Antarctic is contributing seven times as much to
sea level rise as it was just 20 years ago. As a result, sea levels are
rising at unprecedented rates and the world could see a 2-metre rise in
sea levels by the end of the century in the most extreme scenario.
Melting permafrost in the Arctic and Siberia could release huge
amounts of locked-up CO2 and methane, further exacerbating the warming
of the planet.
Meanwhile, glaciers could shrink by 20% this
century, with some regions such as Central Europe seeing a reduction of
more than 80% and Arctic permafrost faces widespread disappearance. It
sounds like a geography lesson. But all of this adds up to serious
impacts for all of us. The glaciers in the Himalayas provide water for
almost 2 billion people and a third of it is predicted to have melted by
the time today’s children are adults.
“The open sea, the Arctic,
the Antarctic and the high mountains may seem far away to many people,”
said IPCC chair Hoesung Lee. “But we depend on them and are influenced
by them directly and indirectly in many ways - for weather and climate,
for food and water, for energy, trade, transport, recreation and
tourism, for health and wellbeing, for culture and identity.”
Some
island nations will become uninhabitable by the end of the century –
the highest point in the Maldives, for example, is about eight feet
above sea level, and the average height above sea level is about four
feet. It’s not just islands that are at risk. More than a quarter of the
world’s population live within 100km of the coast, and less than 100
metres above sea level, including 17 cities with populations of five
million or more. Examples of how this will affect people include the
Mekong Delta in South East Asia, where more ferocious storms and higher
sea levels will make the water more saline and have a potentially
devastating effect on harvests and food prices.
Residents of
coastal cities and towns could see what were previously
once-in-a-century events, such as massive floods, storm surges and
extreme rainfall, becoming annual occurrences by 2050. As well as
causing severe damage to property and local economies, these events
could lead to a wave of climate change-induced migration, increasing
already febrile social tensions.
The fish stocks that we depend on
for our food are going to fall by up to a quarter due to the oceans
becoming warmer and more acidic, with marine mammals also suffering a
15% decline and “almost all coral reefs” set to degrade.
And if
you live in the mountains, home to a tenth of the world’s population,
there will be more landslides as glaciers recede, and less water, which
will hit everything from food production to hydro-electric power
production and tourism.
“The findings of this report are a wake-up
call for everyone – not just for those who live near the ocean,” said
filmmaker and executive director of the Oceanic Preservation Society
Louie Psihoyos. “Our entire global society is reliant on the ocean and
ice systems that regulate our planet. We can no longer afford business
as usual, and it is going to require the participation of each of us.
These signals are too strong for us to ignore any longer – now is the
time for bold, urgent climate action to avoid even more catastrophic
impacts.”
However, there is some hope in the report. We can limit
many of the effects on the oceans if we act now. “If we reduce emissions
sharply, consequences for people and their livelihoods will still be
challenging, but potentially more manageable for those who are most
vulnerable,” says Lee. “We increase our ability to build resilience and
there will be more benefits for sustainable development.”
The
report points out the benefits of ambitious and effective adaptation for
sustainable development and, conversely, the escalating costs and risks
of delayed action. “Various adaptation approaches are already being
implemented, often in response to flooding events, and the report
highlights the diversity of options available for each context to
develop integrated responses anticipating the full scale of future sea
level rise,” said Valérie Masson-Delmotte, one of the authors.
Strongly
reducing greenhouse gas emissions, protecting and restoring ecosystems,
and carefully managing the use of natural resources would make it
possible to preserve the ocean and cryosphere as a source of
opportunities that support adaptation to future changes, limit risks to
livelihoods and offer multiple additional societal benefits, the report
adds, but it is not going to be easy.
“We will only be able to
keep global warming to well below 2°C above pre-industrial levels if we
effect unprecedented transitions in all aspects of society, including
energy, land and ecosystems, urban and infrastructure as well as
industry. The ambitious climate policies and emissions reductions
required to deliver the Paris Agreement will also protect the ocean and
cryosphere – and ultimately sustain all life on Earth,” said Debra
Roberts, another co-author.
“The more decisively and the earlier
we act, the more able we will be to address unavoidable changes, manage
risks, improve our lives and achieve sustainability for ecosystems and
people around the world – today and in the future,” Roberts said.
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