Schindler said while Labor had a commitment to make bigger emissions cuts by 2030 than the Coalition, neither party had targets in line with what would be needed globally to save the reef.
The Intergovernmental Panel on Climate Change found limiting global heating to 1.5C rather than 2C would probably be the difference between the survival of some tropical reef corals and their complete decline. A report by Climate Analytics found the Coalition’s 2030 emissions reduction target was consistent with more than 3C of heating and Labor’s target about 2C.
The director of research at the Climate Council, Dr Simon Bradshaw, said: “This is an issue that cannot be solved with big shiny funding announcements. The science is very clear: in order to save the world’s reefs from total destruction, we must dramatically reduce emissions in the 2020s.”
Scientists started raising the alarm for this year’s bleaching event in December, when ocean temperatures over the reef hit a record high for that month.
Bleaching occurs when the coral becomes stressed from above-average water temperatures. The coral animal expels the photosynthetic algae that lives inside it and provides the coral with food and its colour.
Corals can survive bleaching events. Scientists plan to carry out in-water checks to see how many corals survived and regained their algae and colour between now and the end of the year.
Studies have shown that heat stress can have several “sublethal” effects on corals, including making them more susceptible to disease, slowing their growth and limiting their ability to spawn.
The results of the surveys are expected to inform a report by a United Nations mission that visited the reef in March to check on its health and management. Scientists from Unesco and the International Union for Conservation of Nature were briefed on the surveys during the 10-day monitoring trip. Their report is due before the next world heritage meeting, currently scheduled for June.
Last year, scientific advisors at Unesco recommended the reef be placed on a list of world heritage sites “in danger” due to the impact of the climate crisis and slow progress on improving water quality. Sustained lobbying from the Morrison government led the 21-country committee to go against that advice.
The release of the report and maps follows scientists and conservationists calling on the marine authority to make them public. SBS reported that Paul Hardisty, the chief executive of the Australian Marine Institute of Science, had told a meeting of his staff that the Department of Prime Minister and Cabinet advised releasing the survey results during the federal election campaign would have breached caretaker conventions.
Conservationists have also called on the government to release the state of the environment report, a five-yearly national assessment that has been sitting with the environment minister, Sussan Ley, since December.