Reader Comment of the Week

Climate change is a hot topic. It is also a divisive topic, one where strong opinions and misinformation reign. Typically the strongest opinions come from those with the most to lose. That is, for some, knowing that ways to mitigate dangerous climate change could be detrimental to their hip-pocket clouds judgment.

What we notice at Climate Spectator is that there are many people who fail to understand – or choose to ignore – that global warming does not mean temperatures are getting warmer in every region every year. It is a gradual lift over time, with the trend still well and truly intact. Climate change is also inducing more extreme weather events, which likely means both more droughts and floods in the years to come.

On that note, we welcomed the contribution to our site from Bernard Walsh on Monday in response to a commenter who suggested a future surge in floods could not coexist with the expected surge in droughts:

In today's SMH (pg 2) we have a story whereby the "experts" are predicting a surge in floods, however, only a few years ago the "experts" were predicting a surge in droughts. You can't have it both ways.

Bernard Walsh responded with:

“Actually, you can.

In fact, that's just what the scientists have been predicting for the last few decades (not years, decades).

A warmer atmosphere means more capacity for holding moisture. Which means when it's hot and dry, evaporation can be much worse than 'normal', due to both hotter temperatures and the ability of the air to soak up more moisture. And when it's humid enough to rain, there's a lot more moisture available in the atmosphere to rain out.

Theoretical?  No.  It's been measured – the atmosphere holds, on average, about 4 per cent more moisture than it did 30 years ago.  And have you noticed that lately we've been going from severe drought (such as most of Australia was experiencing for most of the last decade) to extremely heavy, even record-breaking, rain and floods (such as we've experienced over the past few La Nina years), with little in between?

It's far too early to call this the 'new normal' (just not enough data yet), but it is what climate scientists expect to happen as the globe warms.”