The Forest Service is faced with 
assessing the potential impact of 
possible future climate changes and 
differentiating them from the separate 
impact of local air pollution. Further, 
since existing forests were produced 
under different environmental 
conditions than today’s, even without 
any future climate change, tomorrow’s 
forests could be quite different. Thus, 
the Forest Service is confronted with 
great complexity and the challenge of 
developing appropriate data bases and 
models. Such models must be based on 
sound data, much of which ts lacking. 
When they are available, they can 
provide reliable information for 
deciding what to do in many different 
forest ecosystems and locations and 
under various conditions that involve a 
wide range of external variables 
besides the greenhouse gases. 
The foregoing and other policy 
considerations will be reviewed in the 
determination of a recommended RPA 
Program. 
Epilog 
Renewable natural resources will 
always be important to the economic 
welfare and quality of life for the 
citizens of the United States and the 
world. The Assessment has pointed out 
the many opportunities Americans 
have to use these resources to improve 
the public’s economic welfare and 
quality of life. The Nation has made a 
great deal of progress over the past 
several decades in production of 
resources and enhancement of 
productivity. Past performance clearly 
indicates that U.S. resources are 
resilient and renewable and responsive 
to management. Their resilience and 
renewability account for the 
management opportunities we have 
today to increase their products and 
uses as well as their contribution to the 
environment. 
As our Nation continues to grow in the 
coming decades, Americans’ 
perspectives on natural resources will 
change in terms of problems, 
opportunities, and the appropriate mix 
of management inputs to manage the 
country’s renewable resources. This is 
why periodic assessment of the 
renewable resource situation is so 
important in providing the factual basis 
for the 1990 RPA Recommended 
Program. 
Pesticide Precautionary 
Statement 
This publication mentions the use of pesticides 
in one figure caption. The text does not contain 
recommendations for their use, nor does it imply 
that the uses discussed in the figure caption have 
been registered. All uses of pesticides must be 
registered by appropriate State and/or Federal 
agencies before they can be recommended. 
CAUTION: Pesticides can be injurious to 
humans, domestic animals, desirable plants, and 
fish or other wildlife—if they are not handled or 
applied properly. Use all pesticides selectively 
and carefully. Follow recommended practices 
for the disposal of surplus pesticides and 
pesticide containers. 
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