Extreme weather conditions and a changing climate are often recognised by their immediate effects. But as research coming out of the Heatwaves and Cold Air Outbreaks program has shown over the past four months, these events are often generated by distant influences and when they occur have further impact beyond their immediate vicinity.
Research by Elisabeth Vogel produced the quantifiable impact a changing climate and climate extremes have on four of the world’s staple crops — wheat, maize, soybeans, and rice. Her research showed that 18% to 43% of the variation in yield of these crops could be accounted for by extreme weather events. The research also highlighted that specific regions, which produce the vast majority of these crops, were particularly susceptible to extreme events. As a result, extreme weather impacts would be felt far beyond the borders of the countries where these crops are grown.
In a world first, the Heatwaves and Cold Air Outbreaks program produced a global assessment of the drivers of marine heatwaves and found they have increased by 50% over the past century. The researchers revealed that often the instigator of marine heatwaves was found thousands of kilometres away and sometimes in entirely different ocean basins. The international team also uncovered a range of relationships between marine heatwaves and nine well-known climate oscillations that might enhance or suppress their development. This is important fundamental research that will set a baseline for future studies into marine heatwaves and potentially improve our capacity to predict these events.
A very specific piece of research highlighted the importance of understanding these distant linkages. Working with colleagues in South America, our researchers found the extreme drought over South America in 2013/14 and a particularly intense marine heat wave in the southern Atlantic were actually spawned by convection over the Indian Ocean. Importantly, the researchers isolated the mechanism and indicated that strong convection in the Indian Ocean is likely to cause a similar event in the future.
The unpredictable links within the climate system also extend to future warming. Andrew King examined how different areas of the world warm faster than others and explored whether as global warming continues this pattern of accelerated warming will only continue in these fixed locations. He found there would be a slight change but this change differed considerably between the climate models selected. The uncertainty he uncovered between climate models appears to revolve around how they represented precipitation, making this a key focus of future research if we are to improve future projections of warming.
Another area of some uncertainty has been the use of attribution studies to infer the contribution of human caused climate change to extreme heat wave events. Centre researchers identified a range of climate model ensembles that are regularly used for attribution events and found they showed a systematic bias in the way these extreme events were represented. However, they then developed a correction method that ensured these models produced results that were more in line with real-world observations. This newly developed correction method is a major advance towards providing quantifications of climate change that are more meaningful to the real world.
But it hasn’t all been scientific research for the Heatwaves and Cold Air Outbreaks team. Recently, associate investigator Joelle Gergis co-curated an exhibition, Water, soil & life, at the Charles Nodrum Gallery. Each of the pieces on display looked at the variability of Australia’s climate from settlement to today and were combined with passages from Joelle’s recent book, Sunburnt Country: The future and history of climate change in Australia.
Our researchers also received recognition for their work with Sarah Perkins-Kirkpatrick recognised by AGU as an outstanding reviewer in 2018. Annette Hirsch was also the Centre’s first ever winner of the annual CLEX career development award for women and other underrepresented groups.
Congratulations also go to University of Tasmania Honours student Zimeng Su who submitted her Honours theses.
We also welcomed a new PhD student, Xinyang Fan, who will be supervised by Ben Henley.