In the last eight weeks we have had three rain events of around 200 mm and in two of them there have been bursts when the downfall was in the region of 50 mm an hour. We get quite a bit of rain in the winter but this was bordering on the exceptional.
I am part of an environmental group which is improving the quality of water in the Bay of Islands in order to restore the estuary breeding grounds for fish. Erosion of the banks of rivers and streams blankets the normally fertile estuaries with mud and destroys the eco system in which juvenile fish thrive. Without fish nurseries we will not have fish.
We had just planted a section of a stream to restore vegetation to the banks so that the roots hold the soil together to resist erosion when we had the first 200 mm event. This washed a lot of our recent planting out of the ground. We assembled another team of volunteers and replanted the stream edge. Then we had the second flood event which was bigger and did more damage than the first. We were running low on plants by this time but we recovered what we could and planted more trees when we had the third event. The last one did not have a rain burst and so it did not flood to the same extent but it certainly made us think. It also confirmed the value of our work as we could see the amount of soil lost in the small section on which we were working.
On a personal level the gutters on my house, which is thirty years old, were not able to cope with the downpour and overflowed leading to water coming into the house. There are just not enough downpipes to the gutters to drain away rain which falls at the rate of 50 mm an hour. So I am in the process of fitting three new downpipes to cope with future rain events.
Are these events becoming more common. Simple science tells us that for every degree in temperature rise the atmosphere can hold 8% more moisture. New Zealand has had a temperature rise of 0.9 Centigrade and so every rain event has an element of climate change in it.
As Kevin Trenberth said. "The answer to the oft-asked question of whether an event is caused by climate change is that it is the wrong question. All weather events are affected by climate change because the environment in which they occur is warmer and moister than it used to be”.
I study climate change so I am looking for evidence but am I putting two and two together and making five, am I getting paranoid?
Are these events becoming more common. Simple science tells us that for every degree in temperature rise the atmosphere can hold 8% more moisture. New Zealand has had a temperature rise of 0.9 Centigrade and so every rain event has an element of climate change in it.
As Kevin Trenberth said. "The answer to the oft-asked question of whether an event is caused by climate change is that it is the wrong question. All weather events are affected by climate change because the environment in which they occur is warmer and moister than it used to be”.
I study climate change so I am looking for evidence but am I putting two and two together and making five, am I getting paranoid?
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