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Scientific Report 2007-2009
Geophysics
Geophysics and the Environment
The figures here included are an iconic display of the fundamental processes we are dealing with.
Figure 1 shows the skyline of Santiago of Chile (similar to any other large city in the World) in a
given day. The town-enveloping haze is a clear demonstration of air pollution.
Figure 2 is, instead, the time series of the global mean temperature
anomaly (i.e., the departure from a given mean) as reported
by IPCC (Intergovernmental Panel on Climate Change).
A trend toward a warmer climate may be perceived. Despite
the different spatial and temporal scales, these two phenomena
may be the two sides of the same medal. Are, indeed, both
phenomena likely caused by the interactions between Man and
Figure 1: Santiago of Chile skyline in
a typical day.
the environment? If this is the case, the following questions
appear to be unavoidable. Are they an hazard for the Earth
system? Can we monitor the system for identifying the phenomena?
Can we predict these occurences with an useful skill?
The answers are scientifically grounded only if we can rely upon
the understanding of the physical causes of the observed phenomena.
For instance, the polluting substances of Santiago are certainly due to human activities.
The scarce atmospheric dispersion of these substances, however, are equally certainly concurring
in shaping the effect. On the other hand the recent increase (or, better said, any change) of the
Earth’s surface global temperature is surely due to an unbalance of the global Earth’s energy budget
due to the difference between the incoming and the outgoing energy. Both depend, however,
on the detailed atmospheric chemical composition and its physical state. While it is true that
Mankind has changed at various degree this composition, it remains uncertain how much this has
contributed to the unbalance of the Earth’s energy budget.
Figure 2: Global temperature anomalies of the
Earth’s surface.
Therefore, observational and theoretical studies are
mandatory for preventing, mitigating and responding
to the threats to the environment because of Man activities.
The understanding of the Physics controlling
the Earth system, in fact, is the unique method for a
rational deployment of coutermeasures to avoid these
hazards. As today, because the seamless interactions
among the physical processes and their dynamics, only
partial achievements succeeded in the disentanglement
of this complicated net. We know, however, the road
along which to move forward; we have the tools for measuring
and modeling, we understand the need to be fully
integrated in the scientific community.
We are, in fact, establishing methods and instrumentation for: modeling the Earth’s system in
its full complexity, monitoring from the ground Ultra Violet radiation, total Ozone and Nitrogen
dioxide columnar contents, acoustically and optically remote sensing the thermodynamical state
of the atmosphere and the presence of aerosol in populated regions and in Polar regions (within
the Network for the Detection of Atmospheric Composition Change, NDACC).
Alfonso Sutera
Sapienza Università di Roma 165 Dipartimento di Fisica