Det første tiår i dette årtusinde var et historisk varmt årti, hvor klimaforandringerne gik op i gear, konkluderer FN’s Meteorologiske Verdensorganisation (WMO) i en rapport fredag.
WMO fremlægger opsigtvækkende tal, der viser, at det forgangne årti var varmere end andre årtier, man har registreret i moderne tid.
“Årtiet 2001 til 2010 var det varmeste, siden målingerne begyndte i 1850”, skriver WMO.
Ni ud af de ti enkeltår i 2000’erne indskriver sig tilmed helt i top over de varmeste år, der er målt til dato.
“Klimaforan-dringerne finder sted nu og er ikke en eller anden fjern fremtidstrussel, siger chefen for WMO, Michel Jarraud, på baggrund af de nyeste tal.
GENEVA, 23 MARCH 2012: The World Meteorological Organization’s Annual Statement on the Status of the Global Climate said that 2011 was the 11th warmest since records began in 1850. It confirmed preliminary findings that 2011 was the warmest year on record with a La Niña, which has a cooling influence.
Globally-averaged temperatures in 2011 were estimated to be 0.40° Centigrade above the 1961-1990 annual average of 14°C.
Precipitation (nedbør) extremes, many of them associated with one of the strongest La Niña events of the last 60 years, had major impacts on the world. Significant flooding occurred on all continents, whilst major droughts affected parts of east Africa and North America.
Arctic sea ice extent fell to near record-low levels. Global tropical cyclone activity was below average, but the United States had one of its most destructive tornado seasons on record.
The annual statement for 2011 was released for World Meteorological Day 23 March. In addition, WMO announced preliminary findings of the soon to be released Decadal Global Climate Summary, showing that climate change accelerated in 2001-2010, which was the warmest decade ever recorded in all continents of the globe.
The rate of increase since 1971 has been “remarkable” according to the preliminary assessment. Atmospheric and oceanic phenomena such as La Niña events had a temporary cooling influence in some years but did not halt the overriding warming trend.
The “dramatic and continuing sea ice decline in the Arctic” was one of the most prominent features of the changing state of the climate during the decade, according to the preliminary findings. Global average precipitation was the second highest since 1901 and flooding was reported as the most frequent extreme event, it said.
“The world is warming because of human activities and this is resulting in far-reaching and potentially irreversible (uigenkaldelige) impacts on our Earth, atmosphere and oceans,” said WMO Secretary-General Michel Jarraud.
HIGHLIGHTS
Temperatures:
The decade 2001-2010 was the warmest since records began in 1850, with global land and sea surface temperatures estimated at 0,46°C above the long-term average (1961-1990) of 14°C. Nine of these years were among the ten warmest on record.
The warmest year on record was 2010, closely followed by 2005, with a mean temperature estimated at 0,53°C above the long-term average. It was the warmest decade ever recorded for global land surface, sea surface and for every continent.
Most parts of Canada, Alaska, Greenland, Asia and northern Africa recorded temperatures for the decade between 1°C and 3°C above the 1961-1990 average.
Nearly 90 per cent of the countries involved in the assessment experienced their warmest decade on record.
The global temperature increase rate has been “remarkable” during the previous four decades, according to the preliminary summary.
The global temperature has increased since 1971 at an average estimated rate of 0,166°C per decade compared to the average rate of 0,06 °C per decade computed over the full period 1881-2010.
Precipitation
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