Saturday, June 21, 2014

Antarctica, the Ozone Hole, and Global Warming

Mount Erebus, Ross Island, Antarctica from above the clouds.
Photo © Bruce Luyendyk

Are Global Warming and the Antarctic Ozone Hole related? Yes. Before I explain that, some basic facts. 

We live in the lower part of the atmosphere called the troposphere where Global Warming is taking place. Above the troposphere is the stratosphere where the ozone hole develops over Antarctica in Southern Hemisphere Spring. Most of us have been near the top of the troposphere – that is where transcontinental jet aircraft fly – about 11 kilometers up (35,000 feet). Another fact – ozone (a molecule of three oxygen atoms - O3) in the stratosphere is good. It shields us from the Sun’s damaging ultraviolet radiation that causes skin cancer. Ozone in the troposphere where we live is bad – a health hazard and greenhouse gas. It is generated there by industrial activity.

So what’s happening and what’s the connection? 

Monday, June 9, 2014

Antarctica: The Problem Child of future sea level change in this century

icebergs in the Ross Sea, Antarctica. Photo © Bruce Luyendyk
Iceberg Ross Sea, Antarctica. Photo © Bruce Luyendyk

A few weeks ago I posted about discoveries that showed dynamic collapse of marine-based parts of the West Antarctic Ice Sheet is underway (May 20, 2014). What I want to explore now is the current thinking of scientists on the role of Antarctica in sea level change this century.

It will come as no surprise that sea level is projected to rise from the influence of global warming. This is discussed in both the Intergovernmental Panel on Climate Change (IPCC) AR5 report (Assessment Report Five 2013) and the 2014 National Climate Assessment. What do these reports say about sea level change and Antarctica’s role – and do the reports address the dynamic collapse scenarios revealed by studies published in the last few months?