Planet
at its hottest in 115,000 years thanks to climate change, experts say
Global
warming is said to be bringing temperatures last seen during an
interglacial era, when sea level was 6-9 meters (20-30ft) higher than
today
Oliver Milman in New
York
@olliemilman
Tuesday 4 October
2016 05.00 BST
The global
temperature has increased to a level not seen for 115,000 years,
requiring daunting technological advances that will cost the coming
generations hundreds of trillions of dollars, according to the
scientist widely credited with bringing climate change to the
public’s attention.
A new paper
submitted by James Hansen, a former senior Nasa climate scientist,
and 11 other experts states that the 2016 temperature is likely to be
1.25C above pre-industrial times, following a warming trend where the
world has heated up at a rate of 0.18C per decade over the past 45
years.
This rate of warming
is bringing Earth in line with temperatures last seen in the Eemian
period, an interglacial era ending 115,000 years ago when there was
much less ice and the sea level was 6-9 meters (20-30ft) higher than
today.
In order to meet
targets set at last year’s Paris climate accord to avoid runaway
climate change, “massive CO2 extraction” costing an eye-watering
$104tn to $570tn will be required over the coming century with “large
risks and uncertain feasibility” as to its success, the paper
states.
“There’s a
misconception that we’ve begun to address the climate problem,”
said Hansen, who brought climate change into the public arena through
his testimony to the US congress in the 1980s. “This
misapprehension is based on the Paris climate deal where governments
clapped themselves on the back but when you look at the science it
doesn’t compute, it’s not true.
“Even with
optimistic assumptions (future emissions reduction) will cost
hundreds of trillions of dollars. It’s potentially putting young
people in charge of a situation that is beyond their control. It’s
not clear they will be able to take such actions.”
The paper, submitted
as a discussion paper to the Earth System Dynamics journal, is a
departure from the usual scientific process as it has yet to be peer
reviewed and has been launched to support a legal case waged by a
group of young people against the US government.
Last year, 21 youths
aged between 8 and 19 years old filed a constitutional lawsuit
against the Obama administration for failing to do enough to slow
climate change. Hansen and his granddaughter are parties to legal
challenge, which was filed in Oregon and asserts that the government
has violated young people’s rights to life, liberty and property.
Recent studies have
cast doubt over whether the world will stay with an aspirational
temperature target set in Paris
Hansen, who has
become increasingly outspoken on climate change since retiring from
Nasa in 2013, said he recognized some scientists might object to
publicizing the paper so soon but that “we are running out of time
on this climate issue.”
The courts need to
step in to force governments to act on climate change because they
are largely free of the corrupting influence of special interests,
Hansen said. He repeated his call for a global tax to be placed upon
carbon emissions and said that fossil fuel companies should be forced
to pay for emissions extraction in the same way the tobacco industry
has been sued over the health impact of cigarettes.
“The science is
crystal clear, we have to phase out emissions over the next few
decades,” Hansen said. “That won’t happen without substantial
actions by Congress and the executive branch and that’s not
happening so we need the courts to apply pressure, as they did with
civil rights.”
Several recent
studies have cast doubt over whether the world will stay with an
aspirational target set in Paris of a 1.5C limit on the average
global temperature rise. This guardrail, and even the 2C limit agreed
by 195 nations, appears dependent on as-yet undeveloped technology
that would remove greenhouse gases from the atmosphere.
Under this scenario,
huge emissions cuts would be supplemented by a widespread conversion
to biofuels that would be burned for energy. The emissions from this
energy would then be buried underground. Some sort of futuristic
technology that sucks CO2 directly from the atmosphere may also be
required.
Hansen said this is
a “dubious” proposition because it requires a vast change in land
use at a time where a growing global population will require more
food. There are also major doubts whether technology to capture CO2
and lock it underground, often touted as a panacea by the fossil fuel
industry, will be developed in time to help avoid the dangerous sea
level rise, drought, heatwaves and disease spurred by warming
temperatures.
Last week, the
National Oceanic and Atmospheric Administration said that carbon
dioxide levels will not drop below the symbolic 400 parts per million
(ppm) mark in our lifetimes – the highest concentration of CO2
since the Pliocene era 3m years ago.
The environment of
this time, where sea levels were around 65ft higher than today and
trees were able to grow near the north pole due to a lack of ice, is
a “bellwether for what future climate might be like,” according
to Bruce Bauer, a scientist with NOAA’s National Centers for
Environmental Information.
Michael Mann, a
prominent climatologist at Penn State University, agreed that CO2
removal will be required if the world was to avoid 1.5C warming
although the 2C limit “could likely be achieved without negative
emissions, but it would require urgent action, as I have argued
myself is necessary.”.
Mann added that
Hansen’s paper is “interesting” but tackles a huge range of
topics and is unconventional in its use as a tool to support a legal
case.
“Along with the
paper being publicized prior to peer review, this will certainly
raise eyebrows about whether or not this breaches the firewall many
feel should exist wherein policy agenda should not influence the way
that science is done,” Mann told the Guardian via email.
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