Abstract: Climate change poses risks to human health and well-being through shifting weather patterns, increases in frequency and intensity of heat waves and other extreme weather events, rising sea levels, ocean acidification, and other environmental effects. Those risks occur against a backdrop of changing socioeconomic conditions, medical technology, population demographics, environmental conditions, and other factors that are important in determining health. Models of health risks that reflect how health determinants and climate changes vary in time and space are needed so that we can inform adaptation efforts and reduce or prevent adverse health effects. Robust health risk models could also help to inform national and international discussions about climate policies and the economic consequences of action and inaction.

Abstract: This paper is about past, present, and future sea
level changes in the southeastern United States. It
is aimed at non-scientists and scientists who are not
specialists in sea level change. Although this report is
about our specific part of the world, sea level change
in any region is best viewed in the context of global
sea level changes. This should be seen as encouraging,
though, since measuring and predicting global sea
level change is a much easier problem than predicting
the changes at any particular location along a coastline.
Global sea level measures the volume of the
oceans. This volume can change only if we add or
remove water, or if we change the mean density of the
water in the oceans. The most likely way to change the
density is to warm or cool the oceans. For example,
warmer water is less dense and therefore takes up
more space, thus raising the sea level. So determining
global sea level change is a relatively easy problem
since we only have to determine how much water is
added or subtracted from the oceans, or how much the
oceans on average are warmed or cooled.
Regional and local relative sea level changes, on
the other hand, are strongly influenced by land motion.
Many people do not realize that the land we are standing
upon is also slowly moving up and down. If the
land is sinking, then the sea level appears to be rising,
and vice versa. Also, even if the oceans are globally
warming, that does not mean that the associated sea
level increase will be felt everywhere uniformly. If our
region is warming at an anomalously high rate, then
we will see a higher rate of sea level change. Similarly,
if the water added from ice melt does not immediately
spread out over the entire ocean, then we may see
higher or lower rates of sea level change. At present
we do not know if our region is set to be a winner or a
loser in this game.
Fortunately, though, the present sea level changes
in the southeastern US region can be accounted for
largely by the global changes once we take into
account the local and regional land motions. The latter
are small at most stations in our region, but nonetheless
need to be accounted for. In some areas along our
coastlines the land motions are in fact dominant.
I will suggest that the best projection of the future
is about 80 centimeters of global sea level increase by
2100, an increase we need to plan for in our region.
This is somewhat larger than the most recent global
assessment from the Intergovernmental Panel on
Climate Change, but I will argue that it is likely our
present best guess. Unfortunately, the uncertainties in
these analyses lead me to conclude that the probability
of a larger increase is more likely than the chance that
it will be substantially smaller.
It may seem a bit tangential, but I will also suggest
that episodic changes due to changes in storm tracks,
frequencies, and intensities should not be ignored.
Climate change will almost certainly be felt most
strongly as changes in what we call weather. Such
changes are potentially the most important thing that
we need to predict in the coming decades.
Finally, I will say that we can likely reduce the
uncertainty in sea level rise rates over the next 10
years, but only if we maintain the superb observational
system that we have in place now. We are now able to
determine sea level change from the global scale, to
the regional scale, and down to the local scale. If we
simply continue to make the observations that we are
making now for another decade, then we will most
likely be able to intelligently inform the public about
the real risks that might be associated with climate
change.