the global climate 2001 2010 - United Nations Environment ...

the global climate
2001– 2010

A decade of climate extremes
SUMMARY REPORT

WMO-No. 1119

WMO-No. 1119
© World Meteorological Organization, 2013

The right of publication in print, electronic and any other form and in any language is reserved by WMO. Short
extracts from WMO publications may be reproduced without authorization, provided that the complete source
is clearly indicated. Editorial correspondence and requests to publish, reproduce or translate this publication
in part or in whole should be addressed to:

Chair, Publications Board Tel.: +41 (0) 22 730 84 03
World Meteorological Organization (WMO) Fax: +41 (0) 22 730 80 40
7 bis, avenue de la Paix E-mail: [email protected]
P.O. Box 2300
CH-1211 Geneva 2, Switzerland

ISBN 978-92-63-11119-7

NOTE

The designations employed in WMO publications and the presentation of material in this publication do not imply the expression of any opinion
whatsoever on the part of WMO concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation
of its frontiers or boundaries.
The mention of specific companies or products does not imply that they are endorsed or recommended by WMO in preference to others of a similar
nature which are not mentioned or advertised.
The findings, interpretations and conclusions expressed in WMO publications with named authors are those of the authors alone and do not
necessarily reflect those of WMO or its Members.

THE GLOBAL CLIMATE
2001–2010

A DECADE OF CLIMATE EXTREMES

SUMMARY REPORT



Foreword

The first decade of the 21st century was the gathering of data from the world’s leading
warmest decade recorded since modern climate data, monitoring and research
measurements began around 1850. It saw centres. These data, together with climate
above-average precipitation, including one information collected through a unique survey
year – 2010 – that broke all previous records. among the world’s National Meteorological
It was also marked by dramatic climate and and Hydrological Services, were also used
weather extremes such as the European to produce the decadal report The Global
heatwave of 2003, the 2010 floods in Pakistan, Climate 2001–2010.
hurricane Katrina in the United States of
America (USA), cyclone Nargis in Myanmar A decadal perspective makes it possible to
and long-term droughts in the Amazon Basin, assess trends and anticipate the future. It can
Australia and East Africa. also inform efforts to develop operational
climate services that provide information and
Many of these events and trends can be forecasts for decision-making in agriculture,
explained by the natural variability of the climate health, disaster risk, water resources and other
system. Rising atmospheric concentrations of sectors. These efforts are being coordinated
greenhouse gases, however, are also affecting through the WMO-led Global Framework for
the climate. Detecting the respective roles Climate Services.
being played by climate variability and human-
induced climate change is one of the key To learn more about the 2001–2010 decade of
challenges facing researchers today. extremes, including the detailed results of the
WMO survey of countries, you are strongly
The World Meteorological Organization encouraged to read the complete technical
(WMO) is proud to be a major contributor to report (WMO-No. 1103), which is available
international efforts to better understand our online on the WMO website.
climate. We sponsor or co-sponsor leading
research and observation programmes,
notably the WMO Global Atmosphere Watch,
the World Climate Research Programme, the
Global Climate Observing System and the
Intergovernmental Panel on Climate Change.

We also produce an annual statement – Status (M. Jarraud)
of the Global Climate – based on the WMO Secretary-General
Climate System Monitoring network. This
international collaboration facilitates the

1. Climate variability and climate change conditions returned from late 2007, a brief
El Niño appeared from June 2009 and then a
The Earth’s climate fluctuates over seasons, strong La Niña episode started in mid-2010.
decades and centuries in response to both This short-term natural variability may have
natural and human variables. Natural climate masked some of the effects of long-term
variability on different timescales is caused by climate change.
cycles and trends in the Earth’s orbit, incoming
solar radiation, the atmosphere’s chemical The closely related Arctic Oscillation and North
composition, ocean circulation, the biosphere Atlantic Oscillation often affect the northern
and much more. hemisphere winter. Since the 1990s, these two
oscillations have remained mostly in a positive
Climate change refers to long-term changes in phase, which is associated with warmer
the average state of the climate and can also and wetter winters in northern and central
be due to natural factors. The rapid changes Europe and the eastern USA, drier winters in
that have occurred since the middle of the past the Mediterranean and cold, dry conditions
century, however, have been caused largely over northern Canada and Greenland. The
by humanity’s emissions of greenhouse gases winter of 2009/2010, however, saw extremely
into the atmosphere. Other human activities negative phases with low winter temperatures
also affect the climate system, including in northern and central Europe.
emissions of pollutants and other aerosols,
and changes to the land surface, such as Unlike these natural back-and-forth
urbanization and deforestation. oscillations, human-caused climate change is
trending in just one direction. This is because
Short-term natural climate variability can often atmospheric concentrations of carbon dioxide,
be linked to recurring patterns of atmospheric methane, nitrous oxide and other greenhouse
pressure and ocean circulation. El Niño and gases are increasing steadily, due to human
La Niña episodes, for example, result from activities. According to the WMO Greenhouse
rapid changes in the sea-surface temperature Gas Bulletin, global-average atmospheric
in the equatorial Pacific Ocean. They influence concentrations of carbon dioxide rose to
weather patterns around the world through 389 ppm1 in 2010 (an increase of 39 per cent
the subsequent large-scale interactions compared to pre-industrial times), methane to
and transfers of heat in the coupled ocean- 1 808.0 ppb1 (158 per cent) and nitrous oxide
atmosphere system. Other patterns affect to 323.2 ppb (20 per cent). This changing
the climate by strengthening or weakening composition of the atmosphere is causing
high-altitude air currents known as jet streams. the global average temperature to rise, which,
in turn, exerts a significant influence on the
The decade 2001–2010 did not experience hydrological cycle and leads to other changes
a major El Niño event, which is normally in climate and weather patterns.
associated with a warming of the global
climate (as occurred for example in the Humanity’s emissions of chlorofluorocarbons
then-record warm year of 1998). La Niña and and other chemicals have also changed the
neutral conditions prevailed until mid-2006, ______
followed by a brief El Niño. Cool La Niña
1 ppm = parts per million; ppb = parts per billion

Table 1. Mixing ratio of Carbon dioxide 2010 Increase since pre- 1991–2000 2001–2010
carbon dioxide, methane Methane industrial times
and nitrous oxide in Nitrous oxide 389 ppm 361.5 ppm 380 ppm
2010 and the decadal 1 808 ppb 39% 1 758 ppb 1 790 ppb
values for 1991–2000 and 323.2 ppb 312.2 ppb 319.7 ppb
2001–2010 158%

20%

2

atmosphere by damaging the stratospheric the 1961–1990 global average of +14.0°C and
ozone layer that filters out harmful ultraviolet +0.21 ± 0.1°C above the 1991–2000 global
radiation. Fortunately, the phase-out of ozone- average. It is 0.88°C higher than the average
depleting substances under the Montreal temperature of the first decade of the 20th
Protocol should allow the ozone layer to recover century (1901–1910).
in a few decades. The Antarctic ozone hole is
believed to influence the Southern Annular A pronounced increase in the global
Mode oscillation and thus the regional climate. temperature occurred over the four decades
Meanwhile, emissions of reactive gases (such 1971–2010. The global temperature increased
as nitrogen oxides and sulphur dioxide) and at an average estimated rate of 0.17°C per
aerosols (such as dust and black carbon) decade during that period, while the trend
also interact with the climate, for example by over the whole period 1880–2010 was only
increasing the health impacts of heatwaves. 0.062°C per decade. Furthermore, the
increase of 0.21°C in the average decadal
2. The warmest decade temperature from 1991–2000 to 2001–2010
is larger than the increase from 1981–1990
The period 2001–2010 was the warmest to 1991–2000 (+0.14°C) and larger than for
decade on record since modern any other two successive decades since the
meteorological records began around the beginning of instrumental records.
year 1850. The global average temperature
of the air above the Earth’s surface over the Nine of the decade’s years were among
10-year period is estimated to have been the 10 warmest on record. The warmest
14.47°C ± 0.1°C. This is 0.47°C ± 0.1°C above year ever recorded was 2010, with a mean

Temperature anomaly (ºC)

Domain 2001–2010 (A) Warmest/least Warmest/coldest
warm year during decade on record (C)
Global Land +0.79ºC Table 2. Surface
2001–2010 (B) 2001–2010 (+0.79ºC) temperature anomalies
Northern Ocean +0.35ºC 2007 (+0.95ºC) 1881–1890 (–0.51ºC) with respect to 1961–
hemisphere Land-ocean +0.47ºC 2001 and 2004 1990: over the globe,
Land +0.90ºC 2001–2010 (+0.35ºC) northern hemisphere and
Southern Ocean +0.41ºC (+0.68ºC) 1901–1910 (–0.45ºC) southern hemisphere
hemisphere Land-ocean +0.60ºC 2003 (+0.40ºC) 2001–2010 (+0.47ºC) for 2001–2010 (A),
Land +0.48ºC 2008 (+0.26ºC) 1901–1910 (–0.45ºC) annual extreme values
Ocean +0.29ºC 2010 (+0.54ºC) 2001–2010 (+0.90ºC) for 2001–2010 (B) and
Land-ocean +0.33ºC 2008 (+0.35ºC) 1881–1890 (–0.52ºC) decadal extreme values
2007 (+1.13ºC) 2001–2010 (+0.41ºC) for 1881-2010 (C) (source:
2004 (+0.76ºC) 1901–1910 (-0.39ºC) UK Met Office and US
2005 (+0.47ºC) 2001–2010 (+0.60ºC) National Oceanic and
2008 (+0.33ºC) 1901–1910 (-0.38ºC) Atmospheric Administration
2010 (+0.69ºC) 2001–2010 (+0.48ºC) (NOAA) for global analyses
2008 (+0.53ºC) 1901–1910 (–0.53ºC) combined; NOAA-National
2005 (+0.67ºC) 2001–2010 (+0.29ºC) Climate Date Center
2001 (+0.34ºC) 1901–1910 (–0.51ºC) (NCDC) for the northern and
2002 (+0.34ºC) 2001–2010 (+0.33ºC) southern hemispheres)
2008 (+0.20ºC) 1901–1910 (–0.51ºC)
2009 (+0.38ºC)
2008 (+0.24ºC)

3

Figure 1. Decadal global temperature anomaly estimated at 0.54°C particularly in 2010, when records were
combined surface-air above the 14.0°C baseline, followed closely broken by over +1°C in some areas. At the
temperature over by 2005. The least warm year was 2008, with national level, a large majority of countries
land and sea-surface an estimated anomaly of +0.38°C, but this responding to the WMO survey reported
temperature (°C) was enough to make 2008 the warmest La that they experienced their warmest
obtained from the Niña year on record. decade on record. Many geographically
average over the three large countries and regions saw decadal
independent datasets The 2001–2010 decade was also the temperature anomalies over 2001–2010 that
maintained by the UK Met warmest on record for both land-only and exceeded +1°C relative to the long-term
Office Hadley Centre and ocean-only surface temperatures. The average of  1961–1990.
the Climatic Research warmest worldwide land-only surface-air
Unit, University of East temperature was recorded in 2007, with Europe experienced above-normal
Anglia, in the United a temperature anomaly of +0.95°C. The temperatures between 2001 and 2009,
Kingdom (HadCRU), warmest worldwide ocean-only surface with 2007 the warmest year on record for
NOAA-National Climatic temperature was measured in 2003, with large parts of the region. Europe, including
Data Center (NCDC) an anomaly of +0.4°C above the 1961–1990 Greenland, saw a median temperature
and the US National average. This is consistent with climate- anomaly of +1.0°C for the decade. Greenland
Aeronautics and Space change science, which projects that the recorded the world’s largest decadal mean
Administration-Goddard ocean surface will warm more slowly than temperature anomaly of +1.71°C.
Institute for Space the land because much of the additional
Studies (NASA-GISS). heat will be transported down into the ocean Much of Asia also saw anomalies exceeding
The horizontal grey line depths or lost through evaporation. +1°C over the course of the decade, including
indicates the long- China, the Islamic Republic of Iran, Mongolia
term average value for When considered region by region, most and the Russian Federation. For the whole
1961–1990 (14°C). areas of the world also experienced above- continent the median temperature anomaly
average temperatures during the decade, of the decade was +0.84°C.

14.500 14.47

14.225 14.26
14.12
Global temperature (°C)
13.950 13.89 13.95 13.92 13.93 13.95

13.76

13.68 13.67 13.64
13.675 13.59

13.400

1881 1891 1901 1911 1921 1931 1941 1951 1961 1971 1981 1991 2001
1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

4

0.6 Figure 2. Annual global
surface temperature
0.5 anomaly for 1950–2010
with reference to the
0.4 1961–1990 base period,
0.3 indicating the years with
0.2 La Niña events (blue)
0.1 and those with El Niño
events (red) (source:
0 HadCRU, NOAA-NCDC
and NASA-GISS )

–0.1

–0.2

–0.3 1956 1962 1968 1974 1980 1986 1992 1998 2004 2010
1950

Africa experienced warmer-than-normal highest anomaly of +1.3°C, making 2001–2010
conditions in every year of the decade. The the country’s warmest decade.
highest temperature anomalies occurred in
countries north of the Equator. South of the In Oceania, Australia, French Polynesia, New
Equator, Angola, Botswana, Madagascar, Caledonia, New Zealand and Tonga reported
Namibia, South Africa and Zimbabwe positive temperature anomalies in the last
confirmed temperature anomalies in the two decades, with a median value of +0.34°C
range of +0.5°C to +1°C. The median for the 2001–2010 decade. In Australia, the
temperature anomaly of the decade in Africa largest country of the region, 2001–2010 was
was +0.7°C the warmest decade ever, with an anomaly
value of +0.48°C.
The largest country in South America, Brazil,
recorded the continent’s highest temperature As shown in Figures 1 and 2, the decade 2001–
anomaly value of + 0.74 °C, making the decade 2010 continued the upward trend in global
the warmest on record there. The median temperatures, despite the cooling effects of
value of the decadal temperature anomalies multiple La Niña episodes and other natural
started to turn positive in 1981–1990 and year-to-year variability.
reached +0.60°C in 2001–2010.
3. Hot and cold extremes
In North and Central America, Canada and
the contiguous USA and Alaska, which While the average annual temperature is an
together constitute by far the region’s largest important climate indicator, the temperatures
land area, recorded a combined average that people experience can differ greatly
temperature anomaly greater than +0.5°C. from day to day and over the course of a year
On its own, Canada recorded the region’s because of natural climate variability. At the

5

Extreme events, vulnerability, exposure and were fewer deaths due to storms and floods
disasters in 2001–2010 compared to 1991–2000,
with decreases of 16 per cent and 43 per
Monitoring and understanding extreme cent, respectively, thanks, in good part, to
events is important because these events better early warning systems and increased
often destroy lives and property. Extreme preparedness.
events can, however, be prevented from
becoming major disasters by reducing There were fewer deaths, even while
people’s vulnerability and exposure. exposure to extreme events increased as
populations grew and more people were liv-
While databases on disasters are useful ing in disaster-prone areas. According to the
for mapping the behaviour and impact of 2011 Global Assessment Report, the average
extremes in various regions, the data do not population exposed to flooding every year
demonstrate that the increase in observed increased by 114 per cent globally between
losses is caused by an increase in the 1970 and 2010, a period in which the world’s
frequency and intensity of extreme events. population increased by 87 per cent from
Other factors come into play, notably the 3.7 billion to 6.9 billion. The number of
increased exposure of people and property people exposed to severe storms almost
to climate extremes and the improved and tripled in cyclone-prone areas, increasing
increased reporting of disasters. by 192 per cent, in the same period.

Nevertheless, it is worth noting the very While the risk of death and injury from
large increase (more than 2 000 per cent) in storms and floods declined, the vulnerability
the loss of life from heatwaves, particularly of property increased. This is because
during the unprecedented extreme heat the expansion of socio-economic and
events that affected Europe in the summer infrastructural assets led to an increase in
of 2003 and the Russian Federation in the the amount and value of property exposed
summer of 2010. On the other hand, there to weather and climate extremes.

400 000 Casualties 1991–2000 +20%
350 000 Casualties 2001–2010 Total
300 000
Figure 3. Impact of 250 000 –16%
extreme events during 200 000
2001–2010 compared 150 000 2 300% –43%
with 1991–2000: total 100 000 Heat
number of lives lost. The 189% –66%
change in per cent from 50 000 Cold Drought
1991–2000 to 2001–2010 0
is shown above the bars.
(data source: EM–DAT/CRED) Storms (all) Floods

6

same time, human influence has probably cent (14 out of 127) of the countries reported
increased the maximum temperatures of the their absolute daily minimum temperature
most extreme hot nights and days and the record being observed in 2001–2010, compared
minimum temperatures of cold nights and to 32 per cent in 1961–1970 and around 20
cold days. It is also more likely than not that per cent in each of the intermediate decades
human-induced climate change has increased (Figure 4).
the risk of heatwaves.
Over the course of the 2001–2010 decade, many
According to the WMO survey, a total of countries and regions suffered heatwaves at
56 countries (44 per cent) reported their highest one time or another (Figure 5). Some of the
absolute daily maximum temperature record most dramatic included two severe heatwaves
over the period 1961–2010 being observed in in India in 2002 and 2003, which each killed
2001–2010 compared to 24 per cent in 1991– over 1 000 people; the 2003 summer heatwave
2000, with the remaining 32 per cent spread over over much of Europe, which caused more
the earlier three decades. Conversely, 11 per than 66 000 deaths; and the exceptionally

50% Highest maximum temperature Figure 4. Absolute
40% country records of the
30% 1961–1970 1971–1980 1981–1990 1991–2000 2001–2010 daily maximum and
20% Lowest minimum temperature minimum temperature
10% and 24-hour total
1961–1970 1971–1980 1981–1990 1991–2000 2001–2010 precipitation in the last
0% Highest 24-h precipitation five decades (source:
WMO survey)
50% 1961–1970 1971–1980 1981–1990 1991–2000 2001–2010
40% 7
30%
20%
10%

0%
50%
40%
30%
20%
10%

0%

Canada Europe

Central Canada experienced its Much of Europe was affected by
warmest and most humid summer on several extreme heatwaves
record in 2005. 2010 was the warmest during summer 2003.
year on record for the nation as a whole
since records began in 1948. Northern Africa

USA During July and August 2003, within the same
atmospheric pattern that affected Europe, northern
A severe heatwave gripped the south-western Africa experienced record warmth. In Morocco new
USA during July 2005, setting numerous monthly records were set in several areas.
temperature records. Another severe heatwave The heat was most severe in August when
persisted throughout August 2007 across several cities recorded the highest daily
the southern and central part of the USA, maximum temperature ever measured.
with several new all-time high temperature Some of these records were set in
records established. Rabat (44.6°C), Kenitra (47.7°C)
and Tangier (43.5°C).
Brazil
Western Africa
Heatwaves in Brazil from January to March 2006 were
recorded and one of the highest temperatures ever Extreme heat was reported in western
measured (44.6°C) was registered in Bom Jesus on Africa during the boreal summer 2002.
31 January 2006. Abnormally high temperatures were
observed in the Sahara, as high as 50.6°C,
Argentina during June and July 2002.

An extreme climate anomaly hit the region in late October/early South America
November 2009 when an exceptional heatwave affected northern and
central Argentina. Unusually high temperatures of above As part of a persistent atmospheric blocking pattern,
40°C were recorded in many places and for several consecutive an exceptionally hot February affected southern
days. Some annual absolute maximum temperature records were Argentina and Chile in 2008. Daily maximum
broken during this period. temperatures reached between 35°C and 40°C,
well above the average, which ranges
between 20°C and 28°C.

intense and long-lasting heatwave that struck conditions across Europe resulted in over
the Russian Federation in July/ August 2010, 450 deaths. The winter of 2009/2010 was also
causing over 55 000 deaths. The WMO extremely cold in the Russian Federation, North
survey identifies many other abnormally America (particularly the USA) and parts of
high-temperature conditions, heatwaves and Asia. Other cold waves were experienced in the
temperature records around the world. Plurinational State of Bolivia in 2002, southern
Africa in 2002 and 2007, Peru in 2003, Morocco
Despite the record average warmth of the and Algeria in 2005, Australia in 2005, Asia in
decade, cold waves continued to cause intense 2007/2008, and southern China in 2008.
suffering in many countries. Coinciding with
the extreme negative phase of the Arctic 4. Precipitation, floods and droughts
Oscillation and North Atlantic Oscillation,
the northern hemisphere endured extreme In all parts of the world, precipitation, floods
winter conditions from December 2009 to and droughts vary naturally from year to
February 2010. Prolonged cold and snow year and from decade to decade. In addition,

8

Russian Federation China and Japan

As part of a blocking situation, extreme hot The months of August and September 2007 were extremely
weather conditions affected the European part of warm in Japan, setting a new national record of absolute
the Russian Federation during July and August maximum temperature of 40.9°C. In 2010, Japan and China had
2010. This led to disastrous bush fires in the their hottest summer on record.
Moscow region. In Moscow, July mean
temperatures were 7.6°C above normal, making Southern Asia
it the city’s hottest month on record by more
than 2°C. A new record high temperature for the Extremely severe heatwaves hit India in 2002, 2003
city of 38.2°C was set on 29 July, and it reached and 2005. Pakistan and Bangladesh were affected
30°C or above on 33 consecutive days. in May and June 2005 with maximum temperatures
between 45ºC and 50°C and hundreds of related deaths.
Pakistan

In 2010, a pre-monsoon heatwave
brought a record temperature of 53.5°C
to Mohenjo Daro on 26 May making a
national record for Pakistan and the highest
temperature in Asia since at least 1942.

Australia

Several heatwaves affected Australia during
this decade, with disastrous bush fires as well
as record temperatures. During summer
2009, Victoria reached its highest temperature
with 48.8˚C at Hopetown, the highest temperature
ever recorded so far south anywhere in the world.

because warm air can hold more moisture, it 1901, except for the 1950s (Figure 6). In Figure 5. Most
is likely that climate change has influenced addition, 2010 was the wettest year ever significant heatwaves
the occurrence and intensity of extreme recorded at global level. The previous and abnormally high
precipitation events. Greater warmth also wettest years were 1956 and 2000, which, temperature conditions
speeds up the hydrological cycle, which like the second half of 2010, coincided with reported during
should contribute to both heavier rainfall strong La Niña events. 2001–2010 (source:
and increased evaporation. The largest NOAA-NCDC )
number of national records for 24-hour Most parts of the globe had above-normal
extreme precipitation events, as reported precipitation (Figure 7). The eastern USA,
in the WMO survey, occurred over the past northern and eastern Canada, and many parts
two decades,1991–2010 (Figure 4). of Europe and central Asia were particularly
wet. Other wetter-than-average regions were
Global land-surface precipitation averaged northern and southern Brazil, Uruguay and
over 2001–2010 was above the 1961–1990 northern and eastern Argentina, southern
average. It was the wettest decade since Africa, Indonesia and northern Australia.

9

Figure 6. Decadal global 20
precipitation anomaly 15
(in mm) relative to 10
the 1961–1990 WMO
standard normal (source: 5
NOAA-NCDC ) 0
–5
Precipitation anomaly (mm) –10
–15
–20 1901 1911 1921 1931 1941 1951 1961 1971 1981 1991 2001

1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

90N

60N

30N

Figure 7. Decadal EQ 120W 60W 0 60E 120E 180
precipitation anomalies 30S
for global land areas 60S
for 2001–2010; gridded 90S
1° raingauge-based
analysis as normalized 180
departures in mm/year
focusing on 1951–2000 –350 –250 –150 –50 50 150 250 350
base period (source: Global
Precipitation Climatology
Centre (GPCC), Deutscher
Wetterdienst, Germany)

10

Regions that experienced below-normal In other regions, cyclone activity was
precipitation included the western USA generally at average or below-average
and Alaska, south-western Canada, central levels. The eastern North Pacific basin saw
South America, most parts of southern and 139 named storms during the decade, of
western Europe, central Africa, most parts which 65 were classified as hurricanes,
of southern Asia and eastern and south- slightly below the average. The majority of
eastern Australia. these tropical cyclones did not make landfall
and did not cause substantial damage. The
According to the WMO survey, floods were 230 tropical cyclones in the North-West
the most frequently experienced extreme Pacific were also slightly below average.
event over the course of the decade. Eastern The most destructive of these storms was
Europe was particularly affected in 2001 Durian, which struck the Philippines in 2006,
and 2005, India in 2005, Africa in 2008, Asia killing more than 1 000 people and affecting
(notably Pakistan, where 2 000 people died 1.5 million.
and 20 million were affected) in 2010, and
Australia, also in 2010. In addition, many The North Indian Ocean saw the deadliest
flash floods with landslides were reported tropical cyclone recorded during the decade,
by other countries. when Nargis struck Myanmar in early
May 2008. More than 138 000 people were
Droughts affect more people than any other reported killed or missing, eight million
kind of natural disaster owing to their large people were affected and thousands of
scale and long-lasting nature. The decade homes were destroyed.
2001–2010 saw droughts occur in all parts of
the world. Some of the highest-impact and Extra-tropical storms can also turn into
long-term droughts struck Australia (in 2002 devastating natural disasters, mainly in mid-
but also in other years), East Africa (2004 latitude regions. Three major extra-tropical
and 2005, resulting in widespread loss of windstorms severely affected Europe: Kyrill
life and food shortages) and the Amazon struck several parts of central Europe in
Basin (2010). 2007; Klaus affected southern Europe in
2009 and Xynthia struck north-western
5. Severe storms Europe in 2010. These storms caused several
billions of US dollars in damage and took
According to NOAA-NCDC, 2001–2010 was nearly 100 lives. According to analyses by
the most active decade since 1855 for tropical the insurance company Munich Re, winter
cyclones in the North Atlantic Basin. An storms in the USA and Canada in 2007 and
average of 15 named storms per year was 2008 rank among the 10 costliest storms
recorded, well above the 1981–2010 long-term since 1980 in terms of insured losses.
average of 12 named storms per year.
6. Shrinking ice and rising seas
The most active season ever recorded was
2005, with a total of 27 named storms, of which The record warmth of the decade 2001–2010
15 reached hurricane intensity and seven were was accompanied by the melting of ice
classified as major hurricanes (Category 3 or caps, sea ice and glaciers and the thawing
higher). Katrina, a Category-5 hurricane, was of permafrost. In addition to being a sign
the most devastating hurricane of the decade, of a warming climate, melting ice and snow
making landfall in the southern USA in August. also affected water supplies, transport

11

Tropical storm Hurricane Katrina Hurricane Bertha
Allison
(August 2005) (July 2008)
(June 2001)
Maximum winds - 280 Maximum winds - 205 km/h.
Maximum winds - 95 km/h. km/h Deadliest hurricane Longest-lived Atlantic July
Deadliest and costliest to strike the USA since tropical cyclone on record.
tropical storm on record in 1928.
the USA. Hurricane Juan

(September 2003)

Maximum winds - 170 km/h.
Worst hurricane to hit Halifax,
Nova Scotia, in modern history.

Hurricane Rick Tropical storm Fay

(October 2009) (August 2008)

Maximum winds - 270 km/h Maximum winds - 110 km/h. First
The second most intense storm in recorded history to strike
hurricaneon record for the Florida (or any state) four times.
basin, behind Linda of 1997.

Hurricane Kenna

(October 2002)

Maximum winds - 270 km/h. Hurricane Wilma Hurricane Lili
The strongest hurricane to strike
Mexico from the Pacific since (October 2005) (September/October
hurricane Madeline in 1976 and 2002)
third strongest on record. Maximum winds - 295 km/h.
The most intense Atlantic Maximum winds - 230 km/h.
Hurricane Sergio hurricane ever recorded. First hurricane to make
landfall in the USA since
(November 2006) Hurricane Michelle hurricane Irene in 1999.

Maximum winds - 175 km/h. (October/November 2001) Hurricane Ivan
The longest-lived November
tropical cyclone on record for (September 2004)
the basin.
Maximum winds - 270 km/h.
Tropical storm Alma Maximum winds - 220 km/h. The most powerful storm to
Strongest hurricane to hit affect the Caribbean in 10 years.
(May 2008) Cuba since hurricane Fox in
October 1952. Hurricane Catarina
Maximum winds - 100 km/h. The first
eastern North Pacific basin tropical (March 2004)
storm or hurricane to make landfall
along the Pacific Coast of Central Maximum winds - 155 km/h. The first
America since records began. documented South Atlantic Ocean
hurricane since geostationary satellite
records began in 1966.

Cyclones maximum
wind legend

63−118 km/h
119−153 km/h
154−177 km/h

178−209 km/h

210−249 km/h
> 249 km/h

routes, infrastructure, marine ecosystems million km2 – 39 per cent below the long-term
and much more. average – occurred in 2007 (Figure 9). This
record was broken in 2012. The estimated
The state of Arctic sea-ice cover in the volume of Arctic sea ice has also been declining
20th century is relatively well documented. Until markedly since 2005, with a new record set
the 1960s, sea ice covered 14–16 million km2 in 2010. Meanwhile, Antarctic sea ice has
of the Arctic in late winter and 7–9 million expanded slightly overall, for reasons that
km2 at the end of the northern summer. Since continue to be investigated.
then it has declined rapidly. The five years
with the lowest ever recorded sea-ice extent The world’s two major ice sheets (long-lived
in September were 2005, 2007, 2008, 2009 ice accumulated over landmass) are in the
and 2010. The record minimum extent of 4.28 Antarctic and Greenland. The loss of net

12

Cyclone Gonu Typhoon Rananim Typhoon Kompasu

(June 2007) (August 2004) (August/September 2010)

Maximum winds - 270 km/h. Maximum winds - 165 km/h. Maximum winds - 195 km/h. Strongest typhoon
The worst tropical cyclone to Strongest typhoon to affect to strike Seoul Republic of Korea in 15 years.
hit Oman since 1945. Zhejiang Province in China
since 1956. Hurricane/typhoon Loke

Typhoon Lekima 2007) (August/September 2006)

(September/October Maximum winds - 260 km/h. The strongest
hurricane ever recorded in the Central
Maximum winds - 130 km/h. Produced heavy Pacific Ocean.
rains across Viet Nam, resulting in its worst
flooding in 45 years. Typhoon Tokage

(October 2004)

Maximum winds - 230 km/h
Deadliest typhoon to strike
Japan since 1979.

Typhoon Durian Typhoon Megi
(November 2006)
Cyclone Laila (October 2010)
(May 2010) Maximum sustained wind - 230 km/h.
Maximum winds - 120 km/h Maximum winds - 295 km/h. The
First may storm to affect Cyclone Nargis Near 1 200 deaths in the Philippines. strongest tropical cyclone in the
world since 2005 and the strongest
south-eastern India in two (April/May 2008) in the North-West Pacific since 1983.
decades.
Maximum winds - 215 km/h. The most Cyclone Ului
devastating cyclone to hit Asia since 1991
and the worst natural disaster on record (March 2010)
for Myanmar.
Maximum winds - 260 km/h. One
Cyclone Dina more details on Australia of the fastest intensifying tropical
cyclones on record.
(January 2002)
Cyclone Larry
Maximum winds - 240 km/h Responsible
for setting a new 24-h precipitation (March 2006)
record in Mauritius (745 mm).
Maximum winds - 215 km/h. The
Cyclone Gamède most intense cyclone to strike the
Queensland coast since 1918.
(February/March 2007)
Cyclone Ingrid
Maximum winds - 195 km/h. A new worldwide
rainfall record was set in La Réunion with 3929 (March 2005)
mm measured in 3 days.
Maximum winds - 250 km/h. The first
cyclone recorded to reach category 5
intensity off the coast of three different
Australian states: Queensland, Northern
Territory, and Western Australia.

mass from both of these sheets has been have been rising, with the 2001–2010 decade Figure 8. Most significant
accelerating, with the largest losses of the marked by an increase in the thickness of the tropical cyclones
decade seen in 2007 and 2008. If this trend seasonal thaw layer in many northern areas. recorded during
continues, ice sheets will contribute more 2001–2010 (source:
to sea-level rise in the 21st century than any As a result of this widespread melting (and the NOAA-NCDC )
other factor. thermal expansion of sea water), global mean
sea levels continued to rise over the decade
The world’s glaciers lost more mass in 2001–2010. The observed rate of increase
2001–2010 than in any decade since records was some 3 mm per year, about double the
began. Snow cover declined significantly in the observed 20th century trend of 1.6 mm/yr.
northern hemisphere (Figures 10 and 11). The Global sea levels averaged over the decade
temperatures of permafrost (frozen land) areas were about 20 cm higher than those of 1880.

13

Figure 9. Sea-ice extent 12
for September 2007; the
magenta line indicates Extent (millions of square kilometres) 10
the long-term median
from the 1979–2000 base 8
period (left) and Arctic
sea-ice extent at the 6 2010
end of the summer melt 2009
season from 2007 to 2010 4 2008
(right) (source: National 2007
Snow and Ice Data Center, 2 1979-2000 Average
USA ) July ±2 Standard deviations

Figure 10. Mean August September October November
cumulative specific
glacier mass balance 15 000
since 1945/1946 (source:
World Glacier Monitoring Mean cumulative specific mass balance 10 000
Service) (mm water equivalent)
5 000
Figure 11. Northern
hemisphere snow- 0
cover anomaly for June
(1970–2010) (data source: –5 000 mean of 10 mountain ranges
Rutgers University Global –10 000 mean of 37 glaciers
Snow Laboratory, USA ). mean of all glaciers
Note: No similar data exist
for the southern hemisphere Snow-cover extent anomaly –15 000
as the land area subject (millions square kilometres) 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010
to seasonal snow cover
(outside the Antarctic) is 6
very small. 4
2
14 0
–2
–4
–6

1970 1974 1978 1982 1986 1990 1994 1998 2002 2006 2010

7. Conclusion Assessing trends in extreme weather and
climate events requires an even longer
Understanding the Earth’s climate and trends timeframe because, by definition, these
in temperature, precipitation and extreme events do not occur frequently. WMO’s
events is of vital importance to human well- Commission for Climatology is currently
being and sustainable development. As the addressing new approaches for the improved
report The Global Climate 2001–2010 confirms, characterization, assessment and monitoring
climate scientists can now link some natural of these events. In addition, promising new
oscillations to seasonal climate trends. They research into the attribution of individual
also understand the mechanisms by which extreme events based on observational and
humanity’s greenhouse-gas emissions are model data is starting to emerge.
raising global average temperatures.
Long-term cryosphere monitoring has
While climate scientists believe that it is not emerged as an urgent priority, both for
yet possible to attribute individual extremes climate research and for understanding the
to climate change, they increasingly conclude practical implications of the widespread
that many recent events would have occurred melting. There are still uncertainties with
in a different way – or would not have occurred respect to the future evolution of ice-
at all – in the absence of climate change. For sheet melting. Understanding cryosphere
example, the likelihood of the 2003 European variability will also help to improve sea-
heatwave occurring was probably substantially level rise projections, which, in turn, will
increased by rising global temperatures. contribute to more effective coastal planning
and management.
No clear trend has been found in tropical
cyclones and extra-tropical storms at the As observation, modelling and scientific
global level. More complete datasets will be understanding of the climate system advance,
needed in order to perform robust analyses scientists will be able to provide increasingly
of trends in the frequency and intensity of useful information for decision-making. This
these hazards. will greatly benefit international cooperation
through the United Nations Framework
Distinguishing between natural climate Convention on Climate Change and the
variability and human-induced climate Global Framework for Climate Services.
change will also require datasets that are WMO remains committed to supporting these
more complete and long-term. A decade efforts through its Members, its programmes
is the minimum possible timeframe for and the regular reports made possible by the
detecting temperature changes. WMO Climate System Monitoring network.

15

For more information, please contact: JN 13658

World Meteorological Organization

7 bis, avenue de la Paix – P.O. Box 2300 – CH 1211 Geneva 2 – Switzerland

Communications and Public Affairs Office
Tel.: +41 (0) 22 730 83 14 – Fax: +41 (0) 22 730 80 27

E-mail: [email protected]

www.wmo.int