1998 Year of the Ocean Impacts of Global Climate Change 



cycle is rooted in the instability of the coupled atmosphere-ocean system and occurs over an 

 irregular, quasi-periodic cycle which varies between three and seven years. 



Seasonal to interannual forecasts of the climate variability from ENSO can now predict 

 climate changes for up to a year. The improved skill and lead time of these forecasts can result in 

 savings of hundreds of millions of dollars a year both in the U.S. economy and abroad. Advanced 

 knowledge of ENSO allows farmers to make decisions to maximize agricultural yields. ENSO 

 forecasts will also improve fisheries management because ENSO episodes strongly influence 

 marine catches from Chile to Alaska. In addition, the benefits of improved predictions to the 

 water resources and energy sectors of the economy are potentially as large as those for 

 agriculture and fishing. 



To produce useful seasonal to interarmual climate forecasts, it is necessary to both 

 implement an operational climate forecasting system and to continue to invest in process and 

 modeling research that leads to improved predictability. In addition, enhanced global observation 

 and data processing systems will continue to be required to support the research and to initialize 

 and validate model predictions. 



The National Oceanic and Atmospheric Administration (NOAA) currently provides 

 operational seasonal forecasts based on a combination of dynamical model and statistical 

 predictions for up to one year in advance for the United States. Although NOAA actively 

 coordinates its efforts with other federal agencies, the global nature of the climate signal requires 

 involvement with universities and international agencies. These partnerships are necessary so 

 that societies from around the world can benefit from the enhanced predictability and learn to use 

 the information for broad-based environmental and economic gain. 



Decadal to Centennial Climate Impacts 



The ocean has a huge capacity to transport and store heat and carbon dioxide (COj), and 

 exchange huge quantities of water and COj with the atmosphere at the sea surface. Ocean 

 transports play a large role in the present climate and its variability. Coupled ocean-atmospheric 

 models used to predict global temperature changes have shown that the ocean has the potential to 

 delay the impact of greenhouse gas emissions and thus affect changes in atmospheric conditions. 

 Models complemented by observations provide the means to distinguish between natural 

 variability on decadal to centermial time-scales and anthropogenic (human influenced) climate 

 change. For example, a recent modeling study, which looked at a long term record of observed 

 and simulated atmospheric temperature, suggests that the recent increases could be related to COj 

 changes. 



Observations describe variations in the climate system while models provide the 

 mechanism to understand why such variations occur, and to predict future evolution of the 

 climate system. To improve our understanding of the climate system, an integrated research 

 program has been established to improve models to better represent climate processes and to 

 collect long-term instrumental and proxy observations in the ocean. The benefits to society of 



G-3 



