With all the chaos that passes for headline news these days,
including the deadly cold snap which defined the last week of January, there
were several news items over just the last month which probably escaped your
notice, but to me, are far more consequential in the long run than the current
scandal de jour.
President Trump scoffed at the lately departed cold snap and
tweeted that we sure could use “a little of that good old-fashioned Global
Warming”.
Actually, no, we don’t.
Let’s talk about that “polar vortex” cold snap. What news
outlets did not tell you is that while the US dealt with record cold
temperatures, vast areas of the planet recorded temperatures up to 18 degrees
ABOVE normal, including Northern Alaska, Spitsbergen (at 78 degrees north
latitude), Northern China, AND Antarctica. Wildfires are currently rampant in
Australia, where temperatures are routinely over 110 degrees right now.
A paper in the journal Science found that the world’s oceans
are heating up 40 percent faster than they thought just 5 years ago, based on a
new evaluation of data collected over the last few decades. Shallower waters
show an acceleration of warming, when comparing trends from before and after
the turn of the 20th century.
A study just released by NASA revealed that a huge cavity,
1000 feet thick and one third the area of Manhattan, has developed under the
Thwaites Glacier, which itself is about the size of Florida. This glacier is
already melting at an accelerated rate, so the existence of this cavity, which
held about 14 billion tons of ice, is of great concern.
Newly published reports in the Proceedings of the National
Academy of Sciences found that Antarctica’s ice loss has risen from 40 billion
tons per year in the 1980s to 250 billion tons per year now. The rate of loss
has tripled just since 2007.
On the other side of the planet, the ice sheet that covers
Greenland is losing ice at a rate of 400 billion tons per year, four times more
than in 2003. Scientists are beginning to wonder if the melting of the
Greenland ice cap is at a “tipping point.”
What is a tipping point?
A tipping point is when any system changes from one stable
state to another. A good analogy is a glass half full of water. It is stable
even if you push it around on the table. However, if you start to lift up one
side of the bottom of the glass, it will eventually get to the point where it
tips over completely. It enters a new stable state, on its side with the water
probably running of the edge of the table. Maybe the glass rolls of the edge of
the table and smashes to pieces on the floor. That’s what we call an
irreversible change of state.
What is a climate tipping point? It is a point where the
process Earth’s changing climate becomes irreversible. The Earth enters a new
state. Tipping points include unstoppable melting of the Greenland Ice Cap,
permanent ice-free summers in the Arctic ocean, or collapse of the West
Antarctic Ice Sheet to name but a few. Scientists used to think this process
would take centuries. Not anymore.
The other take away from these articles is that researchers
are no longer talking about taking action to reverse climate change, only slow
it. What some of the authors are cautiously saying is that we might have
already passed the point of no return.
When will we know for certain that the Earth has arrived at
climate tipping point? When we get there.
Published in the Westborough News, February 15, 2019