Before the end of this month, the Australian Bureau of Meteorology is likely to announce the arrival of a La Niña weather event, the second in two years. The announcement will serve as a useful reminder of what is at stake for Australia in the climate negotiations currently underway in Glasgow.
The El Niño – Southern Oscillation is the most important source of weather variability globally, including extreme temperatures, droughts, heavy rains and tropical storms. Climate change is rapidly increasing their gravity and extreme El Niño events are expected double in less than 10 years.
Australia is one of the most seriously affected. El Niños generally brings dry conditions to eastern Australia. Nine of the 10 driest winter-spring spells on record for eastern Australia occurred during the El Niño years. The severe droughts from 1982, 1994, 2002, 2006 and 2015 were all associated with El Niños. The 2015-16 event significantly damaged agricultural productivity and contributed to the coral bleaching events on the Great Barrier Reef and the early onset of the fire season. Globally, it has been linked to droughts that have created a humanitarian emergency affecting 60 million people on four continents.
In contrast, La Niña conditions tend to increase the frequency and severity of cyclones and bring above average precipitation across Australia. Between 2010 and 2012, for example, successive record La Niña events triggered devastating flooding in Queensland. More than 78% of the state (an area larger than France and Germany combined) has been declared a disaster area and more than 2.5 million Australians have been affected. The 2010 event also had major global impacts, notably in Pakistan, where extreme flooding triggered a humanitarian emergency affecting 20 million people.
In March, a La Niña contributed to severe flooding on the NSW coast, marking the wettest week the region has seen since records began in 1900. Less than seven months separate the conclusion of this La Niña event and the emergence of one that will probably be announced in a few weeks. The BOM announcement means we can expect a wetter than average summer with a higher risk of cyclones and extreme precipitation.
Usually, a wetter season decreases the bush fire risk, but it is important to keep in mind that the above-average precipitation caused by the consecutive La Niña events will also increase vegetation growth in many parts of the country, including the regrowth of forests devastated in the fires of the black summer of 2019-2020. This could significantly increase the risk of a bushfire in the years to come, especially given the generally warmer conditions we can expect from climate change. The summer of 2022-2023 is worrying in this regard, especially if it coincides with the emergence of an El Niño.
One of the reasons that the impacts of El Niño and La Niña are becoming more extreme is that they are occurring in parallel with climate change. Indeed, El Niños is now amplifying already record heating events. Likewise, La Niñas amplifies cyclonic risks that increase due to climate change, such as the more destructive storm surges associated with rising sea levels. The destructive nature of these events will increase rapidly as the climate continues to deteriorate. to warm up.
Experts are also clear that our ability to reliably predict impacts will increasingly be tested. Bushfire expert David Bowman has warned that we need to be prepared for some big surprises. The interactions of climate change with El Niño and La Niña events and other natural climatic factors will confuse our expectations of what is “normal”. They will increasingly contribute to compounding risks with cascading impacts that will exceed the resilience of Australian communities.
Australia is enormously exposed to these climatic hazards. Twenty percent of our GDP and 3.9 million Australians are in areas at high to extreme tropical cyclone risk, and about 11% of our GDP and 2.2 million people are in high-risk locations and extreme bushfires.
And the costs of responding to disasters will rise rapidly. A report just published by the Australian Business Roundtable for Disaster Resilience suggests that the annual cost could rise from $ 38 billion today to over $ 90 billion by 2060. As the report also acknowledges, even this huge increase is a significant underestimate of the real costs because the analysis assumes that climate-induced disasters will occur separately rather than simultaneously as combined events, which is much more likely.
This is the Australian climate context for the negotiations underway in Glasgow. Australia is highly exposed to climate risks and the global window of opportunity to prevent the worst of impacts is closing fast. Unlike other political challenges, there will be no second chance if our efforts fail. The inertia of the climate system will make it impossible to repair the damage later.
Given our exceptional exposure to climate risk, it should be an urgent foreign policy priority for Australia to mobilize faster global greenhouse gas reductions. But the effectiveness of our advocacy on this front will largely depend on the credibility of our national emissions reduction measures. In this regard, Prime Minister Scott Morrison’s recent announcement that Australia will reduce greenhouse gases to net zero by 2050 is a step in the right direction. But we will need to demonstrate greater national climate ambition than that for our global advocacy to be taken seriously.