Our region’s rainforest is a big part of why the Wet Tropics is a World Heritage Area, and it’s also on the front line of climate change in Australia.
A recent online panel discussion, “Data Science in the News: Impact of climate change on the World Heritage values of the Wet Tropics,” brought together some of the scientists who’ve spent decades studying it. The panel was moderated by Emeritus Professor Helene Marsh of James Cook University, and Chrissy Grant, an Eastern Kuku Yalanji woman and Chairperson of the International Indigenous Peoples’ Forum on World Heritage, opened the discussion with an Acknowledgement of Country.
The physical changes already underway
Professor Brendan Mackey (Griffith Climate Action Beacon, and a review editor for the IPCC) explained that Australia’s climate scientists now use regional climate models with a resolution of 4 – 10 kms which is detailed enough to capture the difference between our coast, our mountains and the Tablelands. The data (much of it available through the Queensland Government’s Long Paddock tool) shows:
- Steadily rising average temperatures;
- more days over 35°C each year, and;
- longer, more severe heatwaves.
Rainfall totals aren’t changing as dramatically, but rainfall is becoming more intense when it does fall. Sea level rise is also being mapped in detail through CSIRO’s Coast Adapt platform, showing where inundation is likely along our coastline in the coming decades.
What’s happening to our wildlife
Professor Stephen Williams (JCU) has been tracking rainforest animals across elevation gradients in the Wet Tropics since 2003. Early modelling that year predicted many species could be at risk of extinction this century — predictions that, he says, are now “coming true pretty much exactly.”
Since around 2014, long-term field data shows upland birds and mammals — especially ringtail possums — have declined by as much as 60% in some populations, driven mainly by rising average temperatures and more intense heatwaves. At the same time, species from lower, warmer elevations are moving upslope to take their place.
Professor Susan Laurence (JCU), who also studies rainforests in the Amazon and has led a long-running artificial drought experiment at the Daintree Rainforest Observatory, added that tree mortality rates in long-term Wet Tropics forest plots have doubled over 50 years of monitoring, linked to hotter droughts and “atmospheric drought” (where hot air simply draws more moisture out of plants).
More recently, the panel discussed how ex-Tropical Cyclone Jasper in 2023 — only a category two system — dumped up to 2m of rain in parts of the region and triggered thousands of landslides north of the Daintree, a reminder that too much rain can be just as damaging as too little.
Culture, country and knowledge at risk
Chrissy Grant spoke about the Wet Tropics as a living cultural landscape cared for by more than 20 Aboriginal groups, many of whom hold cultural knowledge and totemic connections to species that are now in decline. She emphasised that Traditional Owners need to be partners in shaping solutions — including contentious tools like translocating vulnerable species to cooler refuges — rather than consulted only after decisions are made.
Evolutionary biologist Professor Darryn Crayn, Director of the Australian Tropical Herbarium, cautioned that translocation is a last resort given how little is known about the complex web of relationships — pollinators, fungi, soil chemistry — that most rainforest species depend on.
What the panel wants to see happen
Asked to prioritise action for the next decade, the panellists pointed to:
- Continued long-term monitoring (paired with new tools like LiDAR and thermal drones);
- Better systems to turn monitoring data into faster management decisions;
- More resourcing for local governments, community groups and Traditional Owner organisations to plan for climate risks;
- Restoring and reconnecting rainforest habitat so species have room to shift as conditions change;
- And, reducing global greenhouse gas emissions. As Professor Williams put it, quoting a colleague, the priority is “mitigation, mitigation, mitigation.”
The panel also debated whether the Wet Tropics should be formally listed as a World Heritage Area “in danger” — a step that could draw more funding and attention, as it has for the Great Barrier Reef, but risks being misread as a failure of local management rather than a global climate problem. There was no full agreement, but several panellists noted that, in practical terms, the decline is already well underway.
The closing message from the panel was that this isn’t a problem to tackle in ‘the future’. The changes are measurable now, and the window to act is closing.