The full title of Prof Orren’s address was: “Extreme Weather Events: Will we get more in the Overberg?” and the answer is a resounding “Yes, we will”.
The activities of the human race – mainly burning fossil fuel and making cement – release about 4 million tons of carbon dioxide gas into the atmosphere every hour of every day.
Carbon dioxide and other ‘greenhouse gases’, together with water vapour trap heat in the atmosphere, which would otherwise have radiated into space. Some of this heat is reflected back to the earth’s surface, raising the temperature of the oceans. The retained heat is the source of a general warming of the earth and its atmosphere, which is an important component of global climate change.
Professor Orren believes that huge amounts of scientific research confirm the reality of global warming. However, he is convinced that we still have the time and the knowledge to mitigate its effects.
The Overberg will be impacted in 4 ways:
- Extreme weather events (torrential rainstorms, heat waves, gales and droughts) will probably not increase in intensity, but will become more frequent, with associated damage and disruption.
- The well-documented and increasing rise in sea level will pose serious problems through beach and cliff erosion, irreversible flooding of low-lying land and rapid destruction of all built structures, such as houses, located on estuaries, beaches or cliffs at or near previous sea level.
- The “Roaring Forties”, gale-force westerlies encircling the globe south of us, are strengthening as they move south, and taking many of our cold fronts with them, as global climate changes progress. “South-easters” will become stronger, and more frequent with warmer, dryer summers; conversely, “north-westers” will be less frequent but more intense when these do arrive.
- The net effect is for a 20% decline in annual rainfall in the Overberg, which causes a worrying 40% decline in river run-off over the next decades. Water resources will become a vital issue.
Professor Orren concluded: “Let us doubt and dither no longer – Global Climate Change is happening and cannot be talked away.”
Your editor believes that we should pay careful heed to the words of an eminent scientist. We should not build new structures anywhere near the sea or rivers, and make provision in the budget for dealing with a lot more flood and storm damage.