IPCC Summary Report about the Physical Science Basis for Climate

Change…

This report summarises the Working Group 1 contribution

to the IPCC’s fifth assessment report on climate change

(due 2014).

This summary tries to explain the scientific basis for

climate change conclusions, and the new science that has

emerged since the last assessment report. FEBRUARY 2014

The science is getting even stronger, with care being taken

to respond to criticism of past reports. This looks like

much better scientific consilience than Darwin had in The

Origin of Species.

The IPCC now says that is extremely likely that human

influence has been the dominant cause of the observed

warming since the mid-20th century.

WHAT DOES IT SAY.

FEBRUARY 2014

The atmosphere and ocean have warmed, the amounts of

snow and ice have diminished, sea level has risen, and

the concentrations of greenhouse gases have increased.

Since the 1950s, many of the observed changes are

unprecedented over decades to millennia.

The increase in concentration of greenhouse gases is the

enhanced greenhouse effect. It is also called radiative

forcing. More than 90% of the extra energy stored in the

last forty years has gone into ocean warming.

.

WHAT ELSE DOES IT SAY.

FEBRUARY 2014

The rate of sea level rise since the mid-19th century has

been larger than the mean rate during the previous two

millennia. And yes, there are multiple lines and levels of

evidence for this. Most of the 20 cm sea-level rise of the

last 100 years has been due to ocean surface warming.

The ocean has absorbed about 30% of our CO2 emissions,

causing ocean acidification. The ocean’s pH is lowering,

upsetting the delicate balance of carbonate concentrations,

causing coral decay to outpace coral formation.

WHAT ELSE DOES IT SAY.

FEBRUARY 2014

• This report is all about ‘global mean’ observations, and obviously there are regional and local variations. A good example is the higher sea-level in the Philippines relative to California, due to the predominant trade winds.

• This report is really well laid out, and really does give good summary language for policy-makers to use. I hope they do; this looks like a slow-onset disaster.

The comments on these slides are the views of Tim Kirby, Sydney.

You should always read the report itself before putting your reputation, or any money on the line.

WHAT DOES IT MEAN.

Tim Kirby, Sydney CA, CIA, LA-EMS

au.linkedin.com/in/timkirbysydney

FEBRUARY 2014

IPCC, 2013: Summary for Policymakers. In: Climate

Change 2013: The Physical Science Basis. Contribution of

Working Group I to the Fifth Assessment Report of the

Intergovernmental Panel on Climate Change [Stocker,

T.F., D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J.

Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley

(eds.)]. Cambridge University Press, Cambridge, United

Kingdom and New York, NY, USA.

REFERENCE

FEBRUARY 2014