1996: warmest year since 1860

UN Chronicle, Summer, 1997

The year 1996 was the warmest on record since 1860 and the consecutive year with positive global temperature anomalies, the World Meteorological Organization (WMO) reported on 30 April, in its annual statement on the status of the global climate.

The most predominant feature of 1996 was the extent and magnitude of heavy precipitation affecting many parts of the world, notably in southern Europe and parts of northern Africa and the Middle East, which were deluged with record rainfalls early in the year. In stark contrast to the very dry conditions that characterized most of the previous decade, the above-normal rainfall brought welcome relief to those in the Iberian Peninsula. It was also the second consecutive year with above-normal hurricane activity, reaching a near-record two-year total. The outstanding exception to those precipitation events was the severe drought in much of northern Mexico and the south-western United States in the first half of the year.

* Although it was one of the coldest years in recent decades in some parts of the world, the global mean temperature was 22 degrees Celsius above the 1961-1990 base-period average, compared to the record anomaly of 38 degrees Celsius in 1995. Therefore, 1996 was not as warm as 1995;

* The mature cold episode conditions - known as La Nina - that developed in 1995 continued through April 1996 and enhanced rainfall over warmer-than-normal waters in the west Pacific. The relative cooling over much of Eurasia is attributed to dramatic shifts in atmospheric circulation patterns, particularly a strong change in the phase of the North Atlantic oscillation;

* The ozone hole over the Antarctic was just as prominent as it has been in recent years, with significant ozone depletion over the northern hemisphere - especially in Europe, the Arctic and north-eastern Atlantic Oceans during the January-March period;

* For the first time since 1985, the snow cover over the northern hemisphere was above the median, totalling 25.4 million square kilometres. It ranked as the fifth snowiest in 24 years of the satellite record.

* In the different regions of the world, 1996 was marked by:

* Dryness in Europe, from the United Kingdom across central Europe to Russia, with Belgium experiencing the driest year since 1833, and the third driest year for England and Wales since 1766;

* By sharp contrast, copious amounts of rainfall brought much-needed relief to north-west Africa, which had been plagued by extreme dryness for the past six years. In some areas, such as in Malaga, Spain and Casablanca, Morocco, winter precipitation amounts more than doubled during the wet season. However, excessive rainfall also resulted in some deaths and disruptions due to local flooding;

* China suffered from the worst flooding in 50 years, resulting in more than 1,000 deaths and property damage affecting at least 20 million people. The Mekong Delta remained flooded for over a month, resulting in the loss of many lives;

* The Indian subcontinent experienced a wetter-than-normal summer monsoon and heavy flooding over its southern regions during the last three months of the year;

* Northern and Central South America had above-normal rain-fall, inundating parts of Argentina, Brazil, Colombia and Paraguay;

* Although there was flooding in the north-western United States, drought conditions prevailed in the south-west. During the period from October 1995 to May 1996, precipitation totals were the lowest in 100 years in Oklahoma and the second lowest in Texas and Arizona. The intensity of the drought severely affected the winter wheat crops and prompted wildfires. By 1 September, 22,945 square kilometres of forests had been consumed by wildfire across the continental United States, the greatest in the 19-year record. It was the warmest year in California since 1895, thereby contributing to forest fires;

* There were record snowfalls in early January over the eastern United States. Measured totals topped 75 centimetres in Philadelphia, establishing a single storm record. Most areas from Washington, D.C. to Rhode Island reported one of the five biggest snowfalls on record, forcing most airports to close. The snow depth in the city of Boston topped 76 centimetres for the first time in its history;

* Exceptional cold and snowy weather conditions affected much of South Africa during July, with temperatures dropping well below freezing and down to -10 degrees Celsius. Some parts of the country received their largest single snowstorm totals in 60 years;

* Parts of Australia and New Zealand experienced excessive rains, causing localized flooding in north-eastern New South Wales and south-eastern Queensland during April and May. Annual rainfall totals in the western South Island of New Zealand reached as high as 3,200 to 3,870 millimetres - 515 to 740 millimetres above normal.