WMO STATEMENT ON THE STATUS OF THE GLOBAL CLIMATE IN 1995 0.5 0.4 0.3 0.2 0.1 0°C -0.1 TEMPERATURE ANOMALY -0.2 -0.3 -0.4 World Meteorological Organization -0.5 WMO-No. 838 -0.6 1865 1875 1885 1895 1905 1915 1925 1935 1945 1955 1965 1975 1985 1995 YEAR WMO-No. 838 © 1996, World Meteorological Organization ISBN 92-63-10838-2 Front Cover: 1995 - GLOBALLY, THE WARMEST YEAR ON RECORD World Global land air and sea-surface temperature anomalies (°C) are computed departures from the 1961-1990 base-period Meteorological means. The fitted curve is a 21-point binomial filter. (Source: Hadley Centre, Meteorological Office and Climatic Research Unit, Organization University of East Anglia, United Kingdom) Geneva - Switzerland Back Cover: Sea-surface temperature anomalies (°C) for December 1994-January 1995 (top) and November 1995 (bottom) computed as departures from the adjusted optimally-interpolated climatology which includes ship observations during the period 1950-1979. (Source: Climate Prediction Center, United States) Special appreciation is extended to Mr C. Ropelewski, Chairman of the WMO Commission for Climatology Working Group on Climate Change Detection, to other members of the Working Group, and to Mr M. Halpert of the Climate Prediction Center in Washington, D.C., who helped prepare the statement. NOTE The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the World Meteorological Organization concerning the legal status Printed entirely on of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. recycled paper 3 FOREWORD There is continuing international concern WMO is responsible for the routine about global warming and its potential to publication of the Climate System Monitoring cause serious disruption to vulnerable social Monthly Bulletin and the biennial Global Climate and economic sectors of society as well as to System Reviews, which are outputs from the sustainable development efforts. As recently Climate System Monitoring Project of the as December 1995, scientists of the World World Climate Data and Monitoring Meteorological Organization/United Nations Programme (WCDMP). Beginning in 1993, Environment Programme (WMO/UNEP) WMO, in its role as a provider of credible Intergovernmental Panel on Climate Change scientific information on climate and its varia- stated that “the balance of evidence suggests bility, began issuing statements on the status a discernible human influence on global of the global climate. This booklet, the third climate”, through emissions of greenhouse in the series, focuses on the status of global gases. At the same time, there is a develop- climate during 1995, and is provided through ing capability within national Meteorological the Climate Change Detection Project of the and Hydrological Services (NMHSs) to WCDMP. provide comprehensive information on past, This statement is a summary of the present, and future (seasons to a year ahead) information provided by the Climate climate and its variations, to a wide spectrum Prediction Center (CPC) in the United States of users. The rapid development of global with inputs from climate centres in communications systems means that such Australia, Canada, Germany, Iceland, information can be provided on a timely basis Netherlands, Russian Federation, Spain, and is, therefore, of great use to national and the United Kingdom. The contributions decision makers. were based, to a great extent, on the obser- Much of our knowledge on climate vational data collected and disseminated on comes from global scientific and technical a continuing basis by the NMHSs of the programmes coordinated by WMO. WMO Member countries. (G. O. P. Obasi) Secretary-General 4 SUMMARY The 1995 estimated global mean surface stratosphere was once again almost totally temperature over land and marine areas was destroyed. Carbon dioxide and methane the warmest since 1861. The warmth could concentrations in the atmosphere increased not be attributed to El Niño/Southern in 1995 at their recent historical rates Oscillation (ENSO) since the contrasting following a slow-down in rates of increase in equatorial Pacific Ocean surface temperature 1992 and 1993. anomalies were averaged to be near normal There were many extreme climatic for the year. In the North Atlantic, however, anomalies and weather events in 1995. The sea-surface temperatures were more than most active hurricane season in the Atlantic 1°C warmer in an area centred on the Azores. Ocean since 1933 caused considerable Parts of Siberia averaged more than 3°C property damage in the Caribbean islands warmer than the 1961-1990 period and many and the south-east coastal areas of the heat-related deaths occurred in both the United States. Following prodigious rains in midwest United States and India during the January and February, which caused massive northern hemisphere summer. As is usual, flooding along major continental European there were regions where the temperatures rivers, the summer over the same region were cooler than normal in 1995, including was of near record heat and, in the United Greenland and the adjacent north-west Kingdom particularly, serious precipitation Atlantic Ocean as well as mid-latitudes of deficiencies caused widespread restrictions the North Pacific Ocean. on water usage. There were examples of With respect to atmospheric consti- beneficial events, including the return of tuents, the ozone hole, which has become a abundant rains to such widely separated but feature of the Antarctic spring period, began drought-stricken regions as north-west earlier and lasted longer than in any previ- Africa/Iberian Peninsula, southern Africa, ous recorded year - ozone in the lower and Australia. 5 THE WARMEST YEAR SO FAR The globally-averaged surface temperature early 1995. A narrow band of the eastern for 1995 was 0.40°C above the 1961-1990 equatorial Pacific is now cooler, indicating a average, according to observations made at weak cold episode (La Niña) condition and land stations along with sea-surface temper- suggesting that, on a global average, 1996 may atures measured from ships and buoys. The be slightly cooler than 1995 (see back cover). previous warmest year since 1861 was 1990, In 1995, the northern hemisphere was which had an anomaly of 0.36°C for the year warmer than in all previous years, but the as a whole (see front cover). southern hemisphere was relatively less warm. Global surface temperatures have now Parts of Siberia were about 3°C warmer than completely recovered from the cooling usual in 1995, because the early part of the year effects associated with the June 1991 erup- was exceptionally warm, whereas 1995 was tion of Mount Pinatubo in the Philippines. A slightly cooler than normal over the Greenland/ prolonged period of the El Niño/Southern north-west North Atlantic region and over the Oscillation (ENSO) warm episode, which mid-latitude North Pacific. It was the coldest dominated the 1991-1994 period, ended in year in Iceland since 1983. These features (see 90N FIGURE 1. Surface temperature anomalies (°C) for January- December 1995. The 45N analysis is based on at least eight months of data for each grid square. Areas with insufficient data are 0 blank. Anomalies are departures from the 1961- 1990 base-period means. (Source: Hadley Centre, 45S Meteorological Office and Climatic Research Unit, University of East Anglia, United Kingdom) 90S 180 120W 60W 0 60E 120E 180 -1 0 1 2 3 4 6 Figure 1) have recurred in many recent years. PROLONGED ENSO WARMING ENDS Also in 1995, the ocean surface was more than 1°C warmer than usual near the Azores. The ENSO warm episode conditions domi- Warm conditions characterized much of nated the tropical Pacific during the period western Europe, reaching record or near from 1990 to early 1995. Thereafter, equatorial record annual means. For instance, in the central and eastern Pacific Ocean surface Netherlands, the mean, spatially-averaged temperature anomalies steadily decreased, temperature for 1995 reached 10.4°C, more becoming negative during the latter half of than 1°C higher than the 1901-1987 average. 1995, as weak cold episode conditions devel- Intense heat, along with high humidity, was a oped in the region. For the first time since feature in July over large areas of the central 1989, equatorial Pacific Ocean surface and eastern United States, and extending into temperatures were below normal throughout central Canada where it was accompanied by the region from the International Date Line severe forest fires. There were over 1 000 eastward to South America. Negative sea- deaths related to the heat. Very high tempera- surface temperature anomalies also spread tures were also prevalent in northern India both north and south from the Equator, so during much of June with temperatures aver- that by the end of 1995 a rather broad band aging up to 5°C above normal, maximum of negative anomalies covered the region (see temperatures reaching 50°C and night-time back cover). Consistent with the reversal in temperatures failing to fall below 25-30°C. the sign of ocean surface temperature anom- Cooling in the lower stratosphere stabi- alies, cloudiness and rainfall decreased to lized in 1995 (see Figure 2) with anomalies less than normal over the central equatorial remaining near the lowest values observed in Pacific and increased to greater than normal the 17-year satellite-measured record. over Indonesia. 1.5 FIGURE 2. Global mean 1.2 lower stratospheric 0.9 temperature anomalies 0.6 (°C) from the Microwave Sounding Unit channel 4. 0.3 The two sharp peaks were ° 0 C associated with the major -0.3 volcanic eruptions of El -0.6 Chichón (March, 1982) and Mount Pinatubo TEMPERATURE ANOMALY -0.9 (June, 1991). The base -1.2 period is for 1982-1991.