Document ID: EPA-HQ-OPP-2010-0761-0005
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2010-11-19T05:00Z

Charge Questions

OPP’s Approach

OPP is seeking guidance on its approach to climate change to date and
suggestions for how to approach future work.  

Comment on the approach that OPP used to evaluate the models in light of
the expected likely effects and impacts of climate change to determine
whether climate change would influence the inputs and parameters.

Of the areas identified as likely to be affected or the effects are
uncertain, please offer suggestions as to the likely importance of these
factors on risk assessment and if likely to be important.  Comment on
potential approaches to address the uncertainty. 

Temporal and Spatial Considerations

OPP reviews chemicals and assesses risks as needed at least every 15
years.  Over a 15 year time period, pesticide use and crop residues from
monitoring data could change as a result of climate change.  

Based on current projections, will the pace of climate change
significantly increase the uncertainty in our exposure assessments?

If yes, which inputs are likely to change in such a manner that the
uncertainty in the exposure assessment would significantly increase? 
Comment on how OPP might explore this issue.

Over time, the environment will change due to climate change and these
changes will be manifested differently in different regions of the
country.  Irrespective of climate change, there already exists a wide
variety of climatic conditions across the country.  Because climatic
conditions greatly vary across the country, often data collected for
exposure assessments are from studies performed at multiple locations
chosen to be geographically representative of the entire country.

Please comment on the geographic changes anticipated due to climate
change relative to the existing climate diversity within the U.S.  Over
what time period might climate change significantly affect the range of
diversity in weather conditions in the U.S in such a way as to
significantly increase our uncertainty in pesticide exposure
assessments?

Use of Historic Data

All exposure assessments rely in some degree on historical data –
weather, residues on food, cultural practices, pesticide use practices,
etc.  In many situations data that are directly used as inputs into an
exposure assessment and can readily be updated with each successive
assessment.  For example, a dietary exposure assessment today would rely
on recent monitoring data, while an assessment in 5, 10 or 15 years from
now would rely on more up-to-date monitoring data than an assessment
conducted today.  In other situations, data are used to develop a
parameter in a model, such as the runoff curve discussed in section
III.B.1.e. of the background paper.  Please comment on the significance
of climate change on the reliability of embedded model parameters.  How
might OPP systematically approach an evaluation of the significance of
such model parameters?

Currently, OPP uses weather data from 1960-90 in its ecological
assessments, giving equal weight to every year.  OPP intends to acquire
more recent data.  Please comment about the effects of using these data
in light of climate change.  If this is viewed as an important factor,
will aggregating the data from 1960-2010 be appropriate in light of
climate change?  For example, would the use of data from the last 10
years be a more appropriate indicator of future weather patterns or
should OPP consider adding a predictive component to weather data?  If
the use of predictive models is appropriate, provide any sources of
ongoing research or relevant models that might be explored. 

Priority Setting

Please consider a systematic approach for OPP to prioritize future work
on Climate Change.  Priority areas to help guide OPP to inputs/models
that would be most important to help assure that our assessments do not
underestimate exposure and risks (include magnitude and uncertainty).