Is global warming a serious issue?

It is important to examine whether global warming is actually occurring, and if it is, whether it is due to human activity that we can do something about.

But I’d like to look first at what scientists are saying they believe will happen during the next 80 years if global warming continues at its current projected rate.  I don’t want to begin with these potential consequences in order to scare anyone with prophetic warnings of doom.  It’s rather because it seems to me it’s something that could be seriously important that we should look at and decide whether we can and should make an attempt to do something about it.

Here is a brief summary of the report commissioned by the World Bank into the potential effects of global warming in the next 80 years.

Warming:  the expectation is that on current trends, the average temperature on Earth will have increased 4 degrees Celsius – just over 7 degrees Fahrenheit – by the end of this century.  The warming will not globally uniform, however, but be greater in places that are already warm, like the Tropics, and Mediterranean countries, parts of which could become uninhabitable for humans to live on a permanent basis.

How much is 4 degrees Celsius?  It’s the difference between now and the last Ice Age, only in the other direction.  The other significant difference is that the temperature changes will occur in a century, instead of a millennium, giving species – including humans – less time to adapt.

Weather:  Weather events will become more frequent and more extreme.  The kinds of hurricanes, tornadoes, typhoons, droughts,and floods with which we are familiar will occur more often and be more ferocious.  The Amazon rain forest will disappear.

The Oceans:  Two important changes are occurring:  the oceans are rising, and are becoming more acid.  The changes are evident already because of the heat from carbon dioxide which has been temporarily stored in the oceans since about 1955.

The acidification could eventually dissolve the world’s coral reefs which have been important barriers reducing flood damage, and which host some species of life not found anywhere else on the planet.  The projected acidification would be unparalleled in Earth’s history and would cause the extinction of many plants, fish, and mammals with which we are familiar.

The increase in the oceans’ water levels are expected to be about three feet (one meter), but eventually could be as much as 12 feet or four meters.  The loss of land around coastal areas and islands will displace hundreds of millions of people.  How many people is that?  500 million people are equal to about 1 in 12 of the world’s population.  That’s also equal to about six times as many who died in the 1st and 2nd World Wars.

Food and Water:  Warmer temperatures lead to a drop in crop yields.  Farmers have been experiencing this decrease since the 1980’s.  If global warming accelerates, the 2012 drought that affected 80% of US agricultural land will recur.  The loss of fish as a result of the ocean’s acidification will also reduce food supplies.

Seawater is apt to get into many of the fresh water sources, making drinking water less available.

If extreme and prolonged weather events occur simultaneously, it will become increasingly difficult to move food from areas that have surplus to those in need.  The insufficient supply of food could be felt everywhere.

Diseases:  The warmer weather would encourage a large increase in diseases like malaria, dengue fever, cholera, diarrhea  and epidemics.  To put that in context, the flu epidemic following World War I took the lives of a hundred million people.  The Black Plague reduced the population of 14th century Europe by as much as 60%.

Social and Economic Breakdowns: Rapid ecological and environmental changes tend to have social, political, and economic consequences.  Wars and violence increase as people struggle for the essentials to stay alive.

In describing the possible effects of global warming, I’ve tried to leave out words like disaster, or catastrophic, or unprecedented.  To some extent, I don’t think these words help.  It’s enough to know that our own children and grandchildren may have their lives destroyed by these forces.  We do not need to multiply them to worry.

We do know that the level of greenhouse gases in our atmosphere is higher than it has been for 15 million years.  If the views represented by the scientists who are warning that it is we who are causing global warming and so our own potential destruction are right, then obviously we want to take them seriously.

What are the chances that the scientists are right?

That’s the question for my next post.



About Terry Sissons

Terry Sissons is the author of The Big Bang to Now: All of Time in Six Chunks, and this blog is a dialogue about the universe and what’s happened in the last 13 billions years.
This entry was posted in saving our home - thoughts about global warming and tagged . Bookmark the permalink.

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