The IPCC process is a major effort to provide a comprehensive overview of the state of
climate science, though as is evident even from the Summary — which, due to the necessity for brevity, tends to downplay uncertainties — there are still many difficult obstacles and uncertainties to overcome in
determining the
influence of
human activities
on the
climate.»
On the question of hurricanes, the theoretical arguments that more energy and water vapor in the atmosphere should lead to stronger storms are really sound (after all, storm intensity increases going from pole toward equator), but
determining precisely how
human influences (so including GHGs [greenhouse gases] and aerosols, and land cover change) should be changing hurricanes in a system where there are natural external (solar and volcanoes) and internal (e.g., ENSO, NAO [El Nino - Southern Oscillation, North Atlantic Oscillation]-RRB-
influences is quite problematic — our
climate models are just not good enough yet to carry out the types of sensitivity tests that have been done using limited area hurricane models run for relatively short times.