NOAA's National Centers for Environmental Information
Global Surface Mean Temperature Anomalies(1901-1998)
 April Temperature Anomalies 1880-1998 |
 Jan-Apr Temperature Anomalies 1901-1998 |
April 1998 was the warmest April of the century, far exceeding any previous April mean temperature, according to the National Climatic Data Center. This conclusion was based on separately examining preliminary land data using the Global Historical Climatology Network, ocean data using the National Centers for Environmental Prediction (NCEP) - Reynolds Sea Surface Temperatures (SST) blended with the United Kingdom Meteorological Office Long Term SST analysis, and a global surface temperature index that combined the ocean and land data. The final ranking may change due to inclusion of new areas of the world not currently represented. However, even with additional data, the land surface, sea surface, and global surface temperatures for April 1998 will remain among the warmest on record. Each of the anomaly time series is based on its respective 1961-1990 mean. ...the data values
The period January-April 1998 was the warmest of the century according to the National Climatic Data Center. This conclusion was based on separately examining preliminary land data using the Global Historical Climatology Network, ocean data using the National Centers for Environmental Prediction (NCEP) - Reynolds Sea Surface Temperatures (SST) blended with the United Kingdom Meteorological Office Long Term SST analysis, and a global surface temperature index that combined the ocean and land data. The final ranking may change due to inclusion of new areas of the world not currently represented. However, even with additional data, the land surface, sea surface, and global surface temperatures for January-April 1998 will remain among the warmest on record. Each of the anomaly time series is based on its respective 1961-1990 mean....the data values
Land and Sea Surface Temperature Anomalies(1982-1998)
...top April Land Surface Temperature Anomalies 1982-98 |
 Jan-Apr Land Surface Temperature Anomalies 1982-98 |
 April Sea Surface Temperature Anomalies 1982-98 |
 Jan-Apr Sea Surface Temperature Anomalies 1982-98 |
 SSMI Derived Mean Temperature Anomaly April 1998 |
The period January-April 1998 was the warmest January-April ever observed from the global area-averaged sea surface temperature. This dataset began in 1982 using NCEP/NOAA's global sea surface temperature data set It was created from both satellite data and ship observations. Each anomaly value is based on the long-term (1982-1996) mean. This 1998 value is partially driven by the powerful El Niño conditions. ...the data values
 NOAA's El Niño Page |
 Accessing Info related to El Niño |
 El Niño/Southern Oscillation |
Global Warming
Most scientists believe we are now seeing the early signals of a global warming. This belief is based upon analyses of many indicators of climate change as related to computer climate model projections. These changes include surface land and ocean temperature increase, glacier retreat, ice shelf disintegration, sea level rise, rainfall increase, and changes in upper air temperature patterns. The warming is most likely caused, at least in part, by the well-documented buildup of greenhouse gases (mostly carbon dioxide) in the atmosphere.The resulting local, regional, and large scale changes in climate, including changes in weather and climate events, will have significant impacts, but the magnitudes of those impacts are still unresolved. They depend on many factors including the rate of future anthropogenic greenhouse gas and aerosol emissions; the sensitivity of economic, social and ecosystems to climate changes; and the exact sensitivity of the climate system to changes in atmospheric composition.
These changes may have some benefits (e.g., plants grow better with more carbon dioxide in the air and a warmer climate may benefit some people living in cold climates). However, the adverse consequences will likely far outweigh the benefits (e.g., major ecosystem and infrastructure disruptions, sea level rise, increases in floods and droughts, increased exposure to tropical diseases).