The global average surface temperature in 2001 is expected to be the second warmest on record, 0.42=B0C above the 1961-1990 average. The warmest year in the 1860 to present record occurred in 1998, according to records maintained by Members of the World Meteorological Organization (WMO). Nine of the ten warmest years have occurred since 1990, including 1999 and 2000, when the cooling influence of the tropical Pacific La Niña contributed to a somewhat lower global average (0.29=B0C and 0.26=B0C above average, respectively). The end of La Niña brought a return of warmer sea surface temperatures to the central and eastern equatorial Pacific in 2001 and was a contributing factor to the higher annual average this year.
These conditions are part of a continuing trend to warmer global temperatures that have resulted in a rise of more than 0.6=B0C during the past 100 years, but the rise in temperature has not been continuous. Since 1976 the global average has risen at a rate approximately three times faster than the century-scale trend (See graph 1). The year 2001 will be the 23rd consecutive year with the global mean surface temperature above the 1961-1990 average.
Regional temperature and precipitation patterns
Regional surface patterns show the presence of above average temperatures across much of the globe in 2001, although large parts of the tropical and north Pacific were cooler than average. Temperatures in Japan are expected to be above normal for the fifth year in a row, but cooler than the past three years. In Norway, the average annual temperature will likely be from 0.3 to 0.5=B0C above the 1961-1990 average, much less than the +1.5=B0C anomaly recorded in 2000. The annual temperature in the United States is expected to be similar to the 2000 average, the 13th warmest since records began in 1895, and temperatures in Australia will likely be near or below the long-term average for the 3rd consecutive year. Canada continued to experience anomalously warm temperatures throughout 2001 and has now had 18 straight seasons of above average temperatures. In the 343-year Central England temperature series, October 2001 was the warmest October on record. Denmark and Germany also experienced their warmest October since records began in the late 19th century, with temperatures in Germany as much as 4=B0C above average. In contrast, the Russian winter was especially severe in 2000-01 (see graph 2). During a two-week period in early 2001, minimum temperatures near -60=B0C occurred across central and southern Siberia, and more than 100 deaths resulted from hypothermia in the Moscow region alone during the long winter season. Northern India also endured extreme cold in January that contributed to more than 130 deaths. In Bolivia, cold temperatures and snowfall affected a large part of the Andean nation in late June and were associated with several deaths in cities such as La Paz, El Alto and Tarija. Record cold also occurred in parts of Sweden in 2001, although the winter season was warmer than average for the country as a whole.
Above average rainfall continued in much of England and Wales during the first 3 months of the year making the 24-month period ending in March 2001 the wettest in the 236-year England and Wales precipitation time series. Northern, western and central areas of Australia received well above average rainfall in 2001, continuing a pattern that has prevailed over the past 3 years. In a 4-day period in January, Alice Springs received 240 mm of precipitation, only 45 mm less than the annual average. Conversely, parts of southwest and much of eastern Australia were drier than normal. Perth, in southwestern Australia, recorded only 98 mm of precipitation from September 2000 to April 2001, 37% of normal, its lowest rainfall total for that period in the 124-year record. In Zambia, the 2000-01 rainy season (October-March) was much wetter than normal in northern areas while drought conditions continued in the southern part of the country. Winter season precipitation (January-February) was 34% of normal in India, the second lowest total in the past 100 years. The summer monsoon season (June-September) was also drier than normal (92% of average) which has exacerbated prevailing water shortages in areas such as West Madhya Pradesh.
Hurricanes, typhoons and floods
The number of hurricanes and tropical storms in the North Atlantic Basin was above average in 2001. There were 15 named storms, five more than the long-term average and similar to 2000. Nine storms reached hurricane strength with four becoming major hurricanes (category 3 or higher, winds > 179 kilometres per hour), continuing a period of greater hurricane activity that began in 1995. In June, slow-moving Tropical Storm Allison brought more than 750 mm of rain to several locations in southeastern Texas. The slow movement and eventual track of Allison across the southern and eastern United States resulted in the most extensive flooding ever associated with a tropical storm. The tropical depression that later became Hurricane Michelle, produced heavy rains, flooding, and ten deaths in Nicaragua and Honduras. After gaining strength in the Caribbean, Hurricane Michelle severely affected the coffee crop in Jamaica before moving over Cuba in early November. It was the strongest hurricane to make landfall in Cuba since 1952, hitting the coastal islands of the country as a category 4 storm and causing at least 5 deaths nationwide.
In the western Pacific, Typhoon Chebi made landfall in southern China's Fujian Province in June with maximum sustained winds near 160 kilometres per hour (km/hr) killing at least 79 people. Typhoons Durian and Utor, although only category 1 typhoons (119-153 km/hr), made landfall within one week of each other, causing numerous deaths and destroying property in the Philippines and southern China. A total of 28 typhoons and tropical storms have formed in the Northwest Pacific Basin thus far in 2001, one more than the 1970-95 average.
Heavy rainfall in Mozambique and Zambia in early 2001 caused as many as 200 deaths, destroyed crops and left hundreds homeless. Torrential rainfall occurred in Java, western Indonesia, in early February producing flooding and devastating landslides in at least 19 districts that led to great loss of life and reports of more than 20,000 homes and thousands of hectares of rice fields destroyed. October 2000 to March 2001 precipitation was exceptional in the Bretagne region of France. The normal annual rainfall was exceeded by 20 to 40% in parts of the region during this 6-month period, and new winter season rainfall records were established in many locations including Rennes (721 mm) and Brest (1260 mm). A third consecutive year of severe flooding occurred in Hungary and parts of Eastern Europe in March. The rain-swollen Tisza River, which rose to 7.6 metres at the village of Zahony, Hungary, reached its highest level in more than 100 years. The previous record was set in 1888.
In Siberia, rainfall and a rapid spring thaw that followed a severe winter resulted in widespread flooding from the Ural Mountains to the Russian Far East. Temperatures from 2-5=B0C above average in May accelerated snowmelt causing ice-jammed rivers to overflow their banks. The homes of more than 300,000 people were lost or damaged in the Siberian Republic of Yakutia, including 14,000 in the city of Lensk. Spring flooding also occurred in the Upper Midwest region of the United States as rapidly melting snow combined with heavy rain from a series of storms. Boat and barge traffic was closed along a 640 km stretch of the Mississippi River, and a state of emergency was declared in many areas.
The worst flooding to affect Poland since 1997 occurred in July as two weeks of heavy rains caused flooding along the Vistula River, displacing 140,000 people from towns and villages in southern and southwestern Poland. Floodwaters killed at least 52 people in Poland and 39 in the Czech Republic. In Vinh, Vietnam, 685 mm of rain fell in a one-week period in late October, contributing to flooding in the Mekong Delta region that caused at least several hundred deaths between August and October. This followed some of Vietnam's worst flooding on record in 2000. Three consecutive months of above average precipitation in Argentina and adjacent areas of Uruguay from August to October led to flooding in the Pampas region of Argentina and inundated more than 3.2 million hectares of agricultural land. Buenos Aires reported almost 250 mm of rainfall in October, more than twice the normal amount. Areas of northern Iran experienced devastating flooding from a single August storm that resulted in at least 183 deaths in the provinces of Golestan and Khorassan. Heavy rains fell in West Africa in September bringing the worst flooding in 10 years along the Niger River in Guinea. Nearly 70,000 people were affected with 17,000 hectares of agricultural land submerged. Thousands of homes were also damaged or destroyed in Chad along the Logone, Chari and Batha rivers. Algeria's worst flooding in almost 40 years killed hundreds of people in the capital, Algiers, in November. More than 100 mm of rain fell in the span of a few hours, exceeding the normal monthly total for the city.
Drought plagues many areas
Devastating drought in central and southern Asia that began in 1998 continued in 2001 over a broad region centered on Iran, Afghanistan and Pakistan. Wet season (November-April) precipitation since 1998-99 has been less than 55% of average. The lack of adequate rainfall has greatly stressed water supplies as well as agriculture and has directly affected more than 60 million people. Periods of extreme heat also occurred in parts of the same region. Many heat-related deaths were associated with temperatures near 50=B0C in parts of Pakistan in early May. There is some evidence that the recent drought is related to the combined effects of a prolonged La Niña and unusually warm sea surface temperatures in the western Pacific and eastern Indian Oceans.
Drought in Kenya and neighbouring countries in the Greater Horn of Africa also continued despite one of the wettest Januarys in 40 years in parts of the region. The long-season rains (March-May) were well below normal with some parts of northeastern Kenya experiencing their driest May since 1961. The short-season rains, which usually begin in October did not fall until November and were primarily short-lived events with very poor distribution, contributing to worsening conditions in areas that have endured persistent drought since late 1998. The drought has been so severe it is affecting the economies and other aspects of society in the region.
Very dry conditions were also prevalent during the austral summer (December-February) and autumn (March-May) over much of Brazil. Although conditions began to improve in November, hydroelectric power stations that supply energy to some of the most heavily populated regions of the country continued to be adversely affected by low water levels. Severe drought and water shortages were also reported in northern China, the Korean peninsula and Japan during the first half of the year. April precipitation ratios were less than 40% of the 1971-2000 average in much of Japan.
Winter precipitation deficits in the western United States worsened already dry conditions in many areas, contributing to water and energy shortages in parts of the region. November 2000 through February 2001 precipitation totals were the second lowest on record in the Pacific Northwest region. Conditions began to improve in late November and early December 2001 as a series of early season storms produced snowpack approaching 25% of the average late season maximum in some areas. Drought conditions also affected Canada from coast to coast. Montreal had 35 straight days with no more than 1 mm of precipitation (a new record), many regions across the south experienced their driest growing season in 34 years, and Saskatoon endured its driest year in over 100 years of record.
This preliminary information for 2001 is based on observations up to the end of November from a network of land-based weather stations, ships and buoys. The data are collected and disseminated on a continuing basis by the National Meteorological and Hydrological Services of the WMO Member countries.
It should be noted that following established practice, WMO's global temperature analyses are based on data sets maintained by the Hadley Centre of the Met Office, UK, and the Climatic Research Unit, East Anglia University, UK as well as another authoritative global surface temperature data set, which is maintained by the USA Department of Commerce's National Oceanic and Atmospheric Administration (NOAA). Results from these two data sets are comparable; both project that 2001 will be the second warmest year globally.
More extensive, updated information will be made available in the annual WMO Statement on the Status of the Global Climate in 2001, to be published in late March 2002.
(*A joint Press Release issued in collaboration with the Hadley Centre of the Met Office, UK, the Climatic Research Unit at the University of East Anglia, UK, and in the USA: the National Climatic Data Centre in Asheville; the Climate Prediction Centre in Washington; University of Alabama in Huntsville; and the International Research Institute in New York. Other contributers were WMO Member countries Australia, Brazil, Canada, China, France, Germany, India, Iran, Jamaica, Japan, Mauritius, New Zealand, Norway, Russian Federation and Sweden as well as the Drought Monitoring Centre in Kenya)
For more information, please contact:
Ms Mo Lagarde
Information and Public Affairs Office
World Meteorological Organization
7 bis, avenue de la Paix
CH 1211 Geneva 2
Tel.+(41 22) 730 8315
Fax.+(41 22) 730 8027
Internet website: http://www.wmo.ch