[Vision2020] Durban, South Africa: WMO Statement at Climate Conference: "irreversible changes in... biosphere"

[Ted Moffett]

http://www.wmo.ch/pages/mediacentre/press_releases/pr_935_en.html

2011: world’s 10th warmest year, warmest year with La Niña event,
lowest Arctic sea ice volume

GENEVA/DURBAN, 29 November 2011 (WMO) - Global temperatures in 2011
are currently the tenth highest on record and are higher than any
previous year with a La Niña event, which has a relative cooling
influence. The 13 warmest years have all occurred in the 15 years
since 1997. The extent of Arctic sea ice in 2011 was the second lowest
on record, and its volume was the lowest.

These are some of the highlights of the provisional annual World
Meteorological Organization Statement on the Status of the Global
Climate, which gives a global temperature assessment and a snapshot of
weather and climate events around the world in 2011. It was released
today at the international climate conference in Durban, South Africa.

“Our role is to provide the scientific knowledge to inform action by
decision makers,” said WMO Secretary-General Michel Jarraud. “Our
science is solid and it proves unequivocally that the world is warming
and that this warming is due to human activities,” he said.

“Concentrations of greenhouse gases in the atmosphere have reached new
highs. They are very rapidly approaching levels consistent with a
2-2.4 degree Centigrade rise in average global temperatures which
scientists believe could trigger far reaching and irreversible changes
in our Earth, biosphere and oceans,” he said.

The WMO’s provisional statement estimated the global combined sea
surface and land surface air temperature for 2011 (January–October) at
0.41°C ± 0.11°C (0.74°F ± 0.20°F) above the 1961–1990 annual average
of 14.00°C/57.2°F, according to the provisional statement. This is the
tenth equal warmest year since the start of records in 1850.

The 2002-2011 period equals 2001-2010 as the warmest decade on record,
0.46°C above the long-term average.

Global climate in 2011 was heavily influenced by the strong La Niña
event which developed in the tropical Pacific in the second half of
2010 and continued until May 2011. It was one of the strongest of the
last 60 years and was closely associated with the drought in east
Africa, islands in the central equatorial Pacific and the southern
United States, and flooding in southern Africa, eastern Australia and
southern Asia.

Strong La Niña years are typically 0.10 to 0.15°C cooler than the
years preceding and following them. 2011’s global temperatures
followed this pattern, being lower than those of 2010, but were still
considerably warmer than the most recent moderate to strong La Niña
years, 2008 (+0.36°C), 2000 (+0.27°C) and 1989 (+0.12°C). Weak La Niña
conditions have redeveloped in recent weeks but have not yet
approached the intensity of those in late 2010 and early 2011.

Surface air temperatures were above the long-term average in 2011 over
most land areas of the world. The largest departures from average were
over Russia, especially in northern Russia where January-October
temperatures were about 4°C above average in places.

The seasonal Arctic sea ice minimum, reached on 9 September, was 4.33
million square kilometres. This was 35% below the 1979-2000 average
and only slightly more than the record low set in 2007. Unlike the
2007 season, both the Northwest and Northeast Passages were ice-free
for periods during the 2011 summer. Sea ice volume was even further
below average and was estimated at a new record low of 4200 cubic
kilometres, surpassing the record of 4580 cubic kilometres set in
2010.

The above-average temperatures in most northern polar regions
coincided with the second-lowest Arctic sea ice minimum extent and the
lowest sea ice volume on record.


Other highlights:

Severe drought, then flood, in east Africa
Major floods in south-east Asia, Pakistan, Central and South America

Deadliest flash flood with landslide in Brazil

A year of extremes in the United States

A dry start to the year in Europe and eastern China

Another year of below-average tropical cyclone activity
Notes to Editors:

The provisional statement is being released at the 17th Conference of
the Parties to the United Nations Framework Convention on Climate
Change, taking place in Durban, South Africa 28 November to 9 December
2011. Final updates and figures for 2011 will be published in March
2012 in the annual WMO Statement on the Status of the Global Climate.
The preliminary information for 2011 is based on climate data from
networks of land-based weather and climate stations, ships and buoys,
as well as satellites. The data continuously feed three main
depository global climate data and analysis centres, which develop and
maintain homogeneous global climate datasets based on peer-reviewed
methodologies. The WMO global temperature analysis is thus principally
based on three complementary datasets. One is the combined dataset
maintained by both the Hadley Centre of the UK Met Office and the
Climatic Research Unit, University of East Anglia, United Kingdom.
Another dataset is maintained by the National Oceanic and Atmospheric
Administration (NOAA), and the third one is from the Goddard Institute
of Space Studies (GISS) operated by the National Aeronautics and Space
Administration (NASA). Additional information is drawn from the
ERA-Interim reanalysis-based data set maintained by the European
Centre for Medium-Range Weather Forecasts (ECMWF).

WMO released its annual Greenhouse Gas Bulletin 21 November. It is available at
WMO Global Atmosphere Watch Programme Web page: http://www.wmo.int/gaw
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Vision2020 Post: Ted Moffett