John’s Blog/Newsletter: SEA LEVEL RISE NOW

The Day After Tomorrow was a good sci-fi film about the shutdown of the gulf stream causing Manhattan to go into a deep freeze, within days. It pretended to be a glimpse into what could happen with climate change. Absolute Nonsense! It was believable only because we have such terrible understanding of geologic timescale. With increased frequency I hear or read such things as:

“Climate Change? Of course, it’s happened before.”

“Sea level will rise a few feet and then go down.”

“These volcanoes, tsunamis, and earthquakes are signs of cataclysm. The magnetic poles are starting to shift AGAIN.”

At the risk of spoiling the party, let’s sprinkle some “reality dust” on those ideas.

CLIMATE AND SEA LEVEL DO CHANGE, but here are some time perspectives:

• Our climate has been rather stable for 10,000 years.
• The so called Medieval warm period, and the Little Ice Age about a thousand years ago, are sometimes cited to dispute that recent carbon emissions are the cause of warming. The evidence indicates that those temperature variations were regional, not global, e.g. Europe. Regardless they were minor enough, that they did not noticeably change sea level, which is the best long term indicator of how much water is frozen as ice, and therefore average global temperature.
• The last time earth was significantly warmer than today, was about 125,000 years ago. At that time, the melting ice caused sea level to be approximately 26 feet (8 m) higher than today.
• If our CO2 levels get to 600 ppm later this century, as will happen if we keep burning all our fossil fuel, we will be back in a climate pattern that has not existed for tens of millions of years. The climate was very different then; quite inhospitable to life as we know it. This should be a cause for real concern.
• We have had ice ages every hundred thousand years over the last several million years. The last ice age peak was 20,000 years ago. At that time, sea level was down almost 400 feet (120 m) below present, due to the vast amount of water contained in the ice sheets, several miles thick.
• When all the ice sheets and glaciers melt, sea level will rise about 250 feet higher (80 m) than present. Even with continued warming that would take MANY centuries, if not MANY millennia.
• Present forecasts are for sea level to rise 3-7 feet by the end of this century, although the projections are updated as the rate of melting increases. Even that small increase will be devastating to coastal communities around the world.

As for the PROJECTIONS OF APOCALYPSE DUE TO REVERSAL OF THE MAGNETIC POLES:

The poles have reversed many, many times over the 4.6 billion years of the planet’s history. The shift is believed to be related to the molten iron deep within the Earth. As we know spinning masses do generate electromagnetic fields with reference to conductors such as iron. Movements of the iron core of our planet would cause a change in the magnetic polarity. The poles do not shift often or quickly however.

• The poles have shifted with erratic intervals ranging from 100,000 years to a million years or more.
• The last time the poles reversed was 780,000 years ago.
• It takes between 1,000 to 10,000 years for the poles to reverse.

In other words there is no reason to lose sleep over the shifting magnetic poles. For more information see “polar reversal” at Wikipedia.

Scientists have DOCUMENTED FIVE MASS EXTINCTIONS OF LIFE IN EARTH’s past. The most recent was the dinosaur extinction 66 million years ago. A Mass Extinction is defined as more than 50% of the species going extinct. Extinctions have been caused by various triggers, including a large asteroid, volcanic eruptions covering thousands of miles, and the release of large quantities of carbon dioxide or methane.

Many scientists now believe we are heading into the sixth great extinction, but it is a bit early to say that with certainty. Dr. Peter Ward, of the University of Washington has identified that all mass extinctions of the last 600 million years occur when the level of atmospheric CO2 rises above a thousand ppm. In the past that has been caused by huge methane releases from within the Earth, or the asteroid that landed in the Yucatan. In our era, it is being caused by the surge in greenhouse gases, caused by burning coal and oil.

The good news is that life always comes back from extinctions, richer than it was before. The bad news is that recoveries from previous mass extinctions have taken about 10 million years. Darn. There is that problem with understanding real timeframes. To quote the famous saying from Apollo 13, “Ah Houston, we have a problem.”

Finally, let’s return to that film, The Day After Tomorrow. It was about the extreme blizzard and deep freeze that occurs within days after the Gulf Stream shuts down. There is growing support for the theory that a shutdown or massive shift in ocean currents could be the trigger for huge climate change. The mechanism is for the huge melting of fresh water polar ice to change the salinity of the ocean. A massive change in salinity can interrupt an ocean current. There is evidence it has happened before. The shutdown or shift of the ocean current would likely take many years, even decades. Again there is some evidence that it has started to occur. When you try to explain this, people immediately say “Like the Day after Tomorrow” which seems like the science fiction that it is. The fact that the movie sped up the timescale by about a thousand times, makes it seem impossible. That adds to our warped sense of time, and makes it harder to explain the very real threat of an abrupt climate crash in the decades ahead.

It is high time for us to have a sense of time when considering real or unrealistic threats. One of the positive things I do advocate in my forthcoming book, is what I call “Intelligent Adaptation.” It is a different attitude about planning for the almost inevitable sea level rise that will last for centuries — looking at realistic timescales. The book “High Tide On Main Street: Rising Sea Level and the Coming Coastal Crisis” should be available in a few months. If you would like to be on the list for publication notice, send a blank email to: book@johnenglander.net