Global Climate Change – Part III

What We Can Expect

In the first of these articles on climate change, some of the current and
predicted temperature trends were discussed. In this, the third in the series,
a look at the trends on the ground and their effects will be discussed. What
will climate change mean for our planet? For us? In the second article we
ound that historic cultures both benefited and became imperiled as a result
of the climate changes they experienced. It will likely be a similar mixed result
for our time; some may find their way of life challenged while others may actually
find that their opportunities improve in the changing times.
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What We Can Expect

In the first of these articles on climate change, some of the current and
predicted temperature trends were discussed. In this, the third in the series,
a look at the trends on the ground and their effects will be discussed. What
will climate change mean for our planet? For us? In the second article we
ound that historic cultures both benefited and became imperiled as a result
of the climate changes they experienced. It will likely be a similar mixed result
for our time; some may find their way of life challenged while others may actually
find that their opportunities improve in the changing times.

The predictable outcomes of climate change can be summarized in a short
list of effects, shown below. These effects are not necessarily good or bad
but they do represent challenges that we must be prepared to face. For all
the effort that has gone into trying to reduce greenhouse gas emissions, very
little has gone into actually preparing the world for what will likely still happen
even if those emissions reductions do occur.

Probable Effects of Climate Change

• Changes in Weather and Rainfall Patterns
• Changing Habitats and Growing Areas
• Rising Sea Levels
• Population Migration

One of the surest outcomes of climate change is a shift in regional weather
and rainfall patterns around the globe. In fact, evidence exists that this is
happening already; satellite imagery of the Sahara Desert shows that, since
1990, the Sahara has been shrinking. Greater rainfall near the southern end
of the desert has meant increased growth in vegetation and experts predict that
by the end of the 21st century, the Sahara will be reduced to its 1901 extent,
when a land survey had been conducted. This fact alone should not be alarming
or create hysteria; the Sahara has waxed and waned many times throughout
recorded human history. That said, it should be taken as an indicator that
change is upon us.

Climate models suggest that water availability and average river flow are
projected to increase at high latitudes and in some wet tropical areas, and
decrease in some dry regions at mid-latitudes and in the dry tropics. It is likely
that larger and more numerous areas will be affected by droughts, while more
frequent heavy precipitation events will increase flood risk. The amount of
water stored in glaciers and snow cover is expected to decline, complicating
water availability in regions where one-sixth of the world population currently
lives.

As weather patterns change, the growing ranges of some crops may shift.
Governments, corporations and individual land owners must be aware of these
shifts and their potential impact. Certainly, modern farmers have more
resources and knowledge at their disposal than their counterparts in medieval
Europe; as such, there is no reason to expect famine. Rather there must be a
general understanding and acceptance that there may come a year when
planting the same crop in the same field no longer makes sense. There are
many crops which do far better in certain climates, even shifting from one
variety to another within the same family of crop can mean a bountiful harvest
in a year that is wetter or dryer than the historical norm. Educating farmers
and land managers about the relationships between crop variety, crop yield
and local climate and making more seed types available could minimize the
impact of climate change on the global food chain. Furthermore, governments,
universities and non profit organizations must continue to offer up to date
forecasts of anticipated climate shifts; in this way the farmers and planners
can leverage their knowledge to achieve the best outcome from year to year
and decade to decade.

As the world warms, ice at the poles will melt; in turn, that melt water will
slightly increase the depth of the world’s oceans. The Intergovernmental
Panel on Climate Change (IPCC) predicts that the global average sea level
will likely rise by 18 to 59 cm (7 to 23 inches) by the end of the 21st century.
The effects of this rise will be most pronounced in low-lying areas near the
coast; coastal erosion and infiltration of sea water into fresh water aquifers
are likely risks. Additionally, it is plausible that fish and shellfish ranges may
shift with the rising waters. Complicating this is that some of the land that
could be underwater in a century is currently in use; to the extent that the
current uses could pollute the water when submerged, governments and
corporations must focus on remediation of these sites in the coming decades.

In response to the changes outlined above, human populations will naturally
shift; people will seek to migrate to the areas where crops and water are more
plentiful. While predictable, this human migration will tax the resources of the
regions to which the people migrate. If well managed, this population shift
could be fairly benign, even beneficial in some ways like increased labor
resources, greater depth of knowledge and skills and even improved cultural
understanding. If not managed, however, human migration can lead to
increased competition for resources and conflict.

Furthermore, as people move about the globe, so will disease. Once again,
the prepared regions will fare well by actively and aggressively educating
both their settled population and the newcomers about the situation.
Immunization, community health outreach and well-managed sanitation will
all play important roles in minimizing the effects of disease and routes of
transmission in these future scenarios. National and regional planners should
begin to include such scenarios in their disaster planning exercises and
readiness training.