More on the IPCC’s leaked climate report: A roundup of media reactions
- 22 Aug 2013, 17:30
- Roz Pidcock
There's a major new report on the state of the climate due next
month from the Intergovernmental Panel on Climate Change.
This week has seen a sneak preview of some of the findings after
journalists got their hands on a leaked summary. Here's a rundown
of what the papers had to say.
What's been leaked?
Every five or six years, the Intergovernmental Panel on Climate
Change (IPCC) produces an
in-depth assessment of the state of research in all areas of
climate science, from rainfall patterns to polar ice. It's not new
science as such, but a mega-summary of the state of the scientific
literature on climate.
The fifth version of the IPCC's report is due to be published in
three parts, starting next month. The first part of the report
is nearing the end of an involved
process of review by experts and governments worldwide and is
not yet in the public domain.
But a summary intended for policymakers appears to have been
leaked to journalists, and Alister Doyle from
Reuters broke the story first last week.
Clear on the causes of warming
Like a number of
others that followed, the Reuters piece focuses on how new
tools and ways to analyse data mean scientists are more confident
about how and why the climate is changing than in the last report
six years ago.
"Climate scientists are surer than ever
that human activity is causing global warming … [The draft report
says] it is at least 95 percent likely that human activities -
chiefly the burning of fossil fuels - are the main cause of warming
since the 1950s."
Doyle describes how the 95 per cent figure is "up from at least
90 percent in the last report in 2007, 66 percent in 2001, and just
over 50 in 1995".
As for what we can expect this century, he says the report
suggests warming somewhere between less than one degree and nearly
five degrees by 2100, depending on how quickly we continue to emit
carbon dioxide. On the reasoning behind the lower end of this
range, Doyle adds:
"[This] is because the IPCC has added
what diplomats say is an improbable scenario for radical government
action - not considered in 2007 - that would require cuts in global
greenhouse gases to zero by about 2070."
Many of the news articles also highlight what the report says
about sea level rise - the
New York Times called it "one of the biggest single worries
about climate change".
The IPCC reportedly projects sea level rise between 29 and 82 cm
by 2100, a considerably larger range than in the 2007 report. This
comes from a
better understanding of how much melting ice sheets contribute.
This is a point
The Independent and
The Telegraph also pick up on, the latter saying "evidence of
rising sea levels is 'unequivocal'".
Bloomberg featured an interview with Kevin Trenberth, climate
scientist at the US National Center for Atmospheric Research, who
warned that "sea level is going to keep rising even if we stabilize
other aspects of the climate system."
Areas of uncertainty
Although scientists are growing in confidence about changes
taking place at the global level, the impacts for specific regions
is less certain. IPCC lead author Reto Knutti, who is quoted in the
Reuters piece, puts this succinctly:
"We have got quite a bit more certain
that climate change ... is largely manmade ... We're less certain
than many would hope about the local impacts."
Reuters also does a good job of explaining that some types of
extreme weather, notably
heavy rainfall, are showing a clear link with rising global
temperatures. But in some places, it appears newer science has
actually lessened confidence about some conclusions. Doyle
"The new study will state with greater
confidence than in 2007 that rising manmade greenhouse gas
emissions have already meant more heatwaves. But it is likely to
play down some tentative findings from 2007, such as that human
activities have contributed to more droughts."
Surface warming slowdown
Daily Mail stuck with the theme of areas of less certainty,
choosing to focus on why surface temperatures - that's the land and
top of the ocean -
haven't risen as fast recently as in previous decades.
The Mail on Sunday has repeatedly suggested this means global
'stopped'. The Mail today takes a different line:
"Global temperatures have continued to
rise, but at a slower rate since 1998, despite greenhouse gas
concentrations peaking due to more emissions."
"[M]ore heat being absorbed by oceans
could explain why global warming seems to have decelerated in
The Mail piece quotes Alistair Doyle's take on what's driving
"Scientists believe causes could
include: greater-than-expected quantities of ash from volcanoes,
which dims sunlight; a decline in heat from the sun during a
current 11-year solar cycle; more heat being absorbed by the deep
oceans; or the possibility that the climate may be less sensitive
than expected to a build-up of carbon dioxide".
It remains to be seen exactly what the new report will say about
how sensitive the climate is to carbon dioxide when it's released
next month - although the
New York Times suggests the lower range of the estimate could
have come down a little since the last report.
But scientists don't generally talk about climate sensitivity in
the context of what's driving the surface warming slowdown. The
scientists we've spoken to
tell us the most likely reason temperature rise has slowed is
that heat is entering
the oceans rather than staying in the atmosphere, which would
make the slowdown we're seeing a temporary thing.
Still, ongoing discussions among scientists allows the Mail to
ask provocatively in a
headline: "Why has global warming slowed? Scientists admit they
don't know why". And the
BBC takes a similar line, characterising recent temperatures as
"a controversial slowdown that scientists have been struggling to
National Geographic and the
New York Times take the time to explain that scientists are
pretty confident the slowdown is likely down to "short term
factors", which won't significantly impact the amount of warming we
can expect in the long term.
Wait and see
The IPCC won't comment on material in the reports before they
are published, and so its response to the leak has been limited to
cautioning against drawing conclusions from the draft, as the
findings are still subject to change.
However, there's not long left to wait now - the IPCC has
just announced the official version of the summary for
policymakers is set for release in just over a month's time.