David Cheal, Redesdale
David Cunningham is right (‘Prophecies vs data’, Opinions, October 2). The existence of hurricanes, cyclones etc. is not, of itself, evidence of climate change.
However, the text of my letter of September 25 originally said (before editing) ‘… NSW (lowest winter rainfalls since records began), Hurricane Florence in the USA (record rainfalls), Typhoon Mangkhut in China and the Philippines (record wind speeds) and successive (unprecedented) coral bleaching in the Barrier Reef’. The emphasis should be on the repeated breaking of longstanding records. And today we have yet another record-breaking extreme – we have just experienced the driest September in Australia since records began (less than a third of the average rainfall). We are seeing new extremes, not repetition of long-standing patterns.
There are references to the Little Ice Age, an event that was focused on Europe and North America and had little impact elsewhere. Current global warming is global in impact and, unlike former warming periods, is occurring while solar activity (a prime driver of warming periods) has remained relatively stable. We know that from the end of the Little Ice Age to the 1950s the sun’s output increased. But since World War II the sun has slowly grown quieter, yet the temperature on Earth has gone up (reference – www.skepticalscience.com/coming-out-of-little-ice-age). Interpretations can vary, but measured facts are harder to dismiss.
Earth’s climate has experienced dramatic climate changes in the past and life has survived. But dramatic past climate changes have also been periods of mass extinctions (e.g. the Permian-Triassic transition, when more than half of all living things died and 90-95 per cent of marine life was extinguished). Hoping we’re not moving into another massive climate change will not prevent it.