Warmer oceans mean less rainfall
A NATURAL cycle that links coral reefs with rainfall over coastal forests is in danger, according to local scientists.
A marine researcher with Southern Cross University fears warmer oceans will impair coral’s ability to produce cloud-seeding chemicals – meaning the oceans will be deprived of cloud cover and there will be less rainfall as clouds hit the coast.
Associate Professor Graham Jones’ resrearch over the past 20 years has been on how coral reefs and the oceans produce a natural gas which creates clouds over the ocean.
He and his research team have found that algae living in coral tissue and in the ocean produce huge amounts of the gas, dimethyl sulphide (DMS), which forms ‘cloud seeds’ when it reaches the air.
The clouds produce rain and reflect sunlight back into space, creating a cooler planet. A rise in ocean temperature of only two degrees Celsius above mean temperatures could cause some algae to stop producing DMS – potentially leading to less cloud formation and less rain.
“It is no coincidence that much of Australia’s rainforest lies adjacent to the northernmost reefs,” Prof Jones said.
“Lower levels of DMS over coral reefs could dry out north Queensland’s rainforests.
“We believe the clouds generated by the corals in the Great Barrier Reef are transported by the south-east trade winds from April toOctober and attract water vapour as they are transported to the rainforests of north Queensland.”
The mechanism needed to be further demonstrated, Prof Jones said, and that would need government funding.
The results of theresearch will be presented at an international symposium at the National Institute of Oceanography in Goa, India, in October and at conferences in Brisbane and Cairns in June.