Sunday, March 6

 

I watched the regional news at 6.30 this morning and saw the heart-breaking scenes of the devastation in Queensland and Northern NSW.  The PM calls it a ‘natural disaster’ but there’s nothing natural about this.  It’s an enormous and growing threat to the future of this country.

 

I remember one day in about 1954, sitting in my classroom at Gwynneville Primary School, watching the teacher, probably Mr Fuller, drawing a diagram on the blackboard. On the left hand side was a blue line, representing the sea, above was a bright yellow sun; on the right was a green representation of fields with a brown mountain looming over them.  Mr Fuller used white chalk to draw arrows showing how the sun draws water from the sea to form clouds, how the wind pushes the clouds across the land and how the water from the clouds drops as rain on the fields below and eventually makes its way back to the sea.  A very simple representation of the water cycle. I used a similar diagram many times when I was teaching.

 

I remember Mr Fuller also telling us that floods are more prevalent in tropical areas because the sun is hotter and draws up more water.  I’m not sure the interaction is as simple as he made out but, of course, he was talking to naïve 10 year-olds.  There are scientists around Australia now trying to make sense of this extraordinary event.  How can so much moisture be carried like a river through the atmosphere between 8 and 10 km above the ground?  One description said that ‘between 26 and 27 February, enough water flowed through the atmospheric river above Brisbane to fill Sydney Harbour 16 times’.  Sydney Harbour holds about 500bn litres. No doubt those climate scientists are trying to get the reality of the new, enhanced water cycle into the heads of decision makers in every country in the world. 

 

Each degree of temperature rise increases the capacity of the atmosphere to hold water vapour by 7% so, as the climate gets hotter, more water will be drawn from the oceans and more will fall on the land.  If more water falls on the land, there will be more ‘flood events’ (as modern nomenclature has it).  It’s not rocket science: it’s much more important than that.