Recent Australian droughts may be the worst in 800 years



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Places such as Berri were affected by Millennium Drought, caused by low cool-season rain. New materials and techniques are now being used to observe drought causes and water patterns in Australia’s history to help the future.
Gary Sauer-Thompson/flickr, CC BY-NC

Mandy Freund, University of Melbourne; Ben Henley, University of Melbourne; Kathryn Allen, University of Melbourne, and Patrick Baker, University of Melbourne

Australia is a continent defined by extremes, and recent decades have seen some extraordinary climate events. But droughts, floods, heatwaves, and fires have battered Australia for millennia. Are recent extreme events really worse than those in the past?

In a recent paper, we reconstructed 800 years of seasonal rainfall patterns across the Australian continent. Our new records show that parts of Northern Australia are wetter than ever before, and that major droughts of the late 20th and early 21st centuries in southern Australia are likely without precedent over the past 400 years.




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This new knowledge gives us a clearer understanding of how droughts and flooding rains may be changing in the context of a rapidly warming world.

A history of drought

Australia has been shaped by floods, droughts, and blistering heat. How big and how intense these events were is poorly understood due to the limited historical and observational records.

Historical records provide rough estimates of the extent and intensity of droughts in parts of Australia since the late 1700s. For example, captains’ logbooks from ships anchored off of Sydney describe the Settlement Drought (1790-1793), which threatened the tenuous foothold of early European settlers in Australia. And farmers’ records describe the Goyder Line Drought (1861–1866) that occurred in areas north of the known arable lands of South Australia.

Observational weather records provide more detailed descriptions of climatic variability. However, systematic recording of weather in Australia only began in the late 19th century. Since then many parts of the continent have experienced prolonged wet periods and droughts. The most well known of these are the Federation drought (1895-1903), the World War II drought (1939-45), and the recent Millennium drought (1997-2009).

All three droughts were devastating to agriculture and the broader economy, but each was distinct in its spatial footprint, duration, and intensity. Importantly, these droughts also differed in seasonality.

Recent and historical droughts in Australia for the different natural resource management (NRM) regions.
Provided by M.Freund

For example, the Millennium drought, which was most severe in southwestern and southeastern Australia, was caused by poor rainfall during the cool season. In contrast, the Federation drought, which affected almost the entire continent, was predominantly due to rainfall declines during the warm season.

Although the historical and observational records provide a wealth of information about the frequency of wet and dry extremes, they provide only part of the picture.

Lancelot that became a ghost town following the Federation Drought.
denisben/flickr, CC BY-ND

Looking back

To understand possible trends in rainfall and assess the likelihood of prolonged droughts, we need to understand the long-term climatic context. For this, we need records that are much longer than existing observational and historical records.

Our new study used an extensive network of tree rings, ice cores, corals, and sediment records from across Australia and the adjacent Indian and Pacific Oceans to extend rainfall records across all of the major regions of Australia by between 400 and 800 years. Importantly, we did this for two seasons, the cool (April–September) season and warm (October–March) season, over eight large natural resource management regions spanning the Australian continent. This allows us to place recent observations of rainfall variability into a much longer context across the entire continent for the first time.

Seasonal rainfall for the past 400 years

We found that recent shifts in rainfall variability are either unprecedented or very rare over the reconstructed period. The two most striking patterns were in tropical northern Australia, which as been unusually wet over the past century, and southern Australia, which has been unusually dry.

Our reconstructions also highlight differences between recent extreme drought events and those in earlier centuries. For example, the Millennium Drought was larger in area and longer than any other drought in southern Australia over the last 400 years.

Our reconstruction also shows that the most intense droughts described in the historical records – the Settlement Drought (1790-93), Sturt’s Drought (1809–30), and the Goyder Line Drought (1861–66) – were limited to specific regions. The Settlement Drought appears to have affected only Australia’s eastern regions, whereas the Goyder Line Drought, which occurred north of the northernmost limit of arable lands in Southern Australia, primarily impacted central Australia and the far north.




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These historical droughts varied widely in the area they covered, highlighting at a continental scale the spatial diversity of drought. This spatial variability has also recently been demonstrated for eastern Australia.

The ConversationOur multi-century rainfall reconstruction complements the recent Climate Change in Australia report on future climate. By providing a clearer window into climates of the past online, we can better see how extremes of rainfall may affect Australia in the future.

Mandy Freund, PhD student, University of Melbourne; Ben Henley, Research Fellow in Climate and Water Resources, University of Melbourne; Kathryn Allen, Academic, Ecosystem and Forest Sciences, University of Melbourne, and Patrick Baker, ARC Future Fellow and Professor of Silviculture and Forest Ecology, University of Melbourne

This article was originally published on The Conversation. Read the original article.

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Rio Tinto’s climate change resolution marks a significant shift in investor culture


Anita Foerster, University of Melbourne and Jacqueline Peel, University of Melbourne

What does the advocacy group the Australian Centre for Corporate Responsibility (ACCR) have in common with the Local Government Super fund, the Church of England Pensions Board, and the Seventh Swedish National Pension Fund?

Quite a lot, it seems. These three institutional investors joined with the ACCR to co-file a shareholder resolution on climate change at mining giant Rio Tinto’s Australian annual general meeting in Melbourne yesterday. While Rio’s board advised shareholders to vote against the resolution, there was a very healthy showing of 18.3% shareholders voting in support (over 20% including abstentions).

The resolution called on Rio to review and comprehensively report on its membership of industry associations such as the Minerals Council of Australia (MCA). The MCA’s pro-coal political lobbying has been distinctly at odds with the position of companies such as Rio, which publicly support measures to reduce carbon emissions in line with the Paris climate agreement.




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This alliance between civil society and institutional investors is significant for several reasons.

Institutional investors (large investors such as superannuation funds which pool money to buy shares and other assets) are increasingly concerned about the long-term resilience of their investments to the business risks posed by climate change.

For an energy-hungry miner such as Rio, these risks include changing energy prices and markets, as well as operational disruptions caused by climate impacts such as storms, floods, and droughts.

Investors want companies to disclose these risks fully and to outline how they will manage them to maintain company value over the long term. As the Rio resolution suggests, they also want companies to be transparent and consistent in their approach to climate change. Paying multimillion-dollar memberships for industry associations that lobby against climate action is inconsistent with the long-term investment goals of such shareholders.

New phenomenon

Shareholder resolutions on climate change are a relatively new phenomenon in Australia. In the United States, however, there is a long history of using resolutions to pressure companies to address human rights abuses and change their approach to issues like climate change.

In Australia, advocacy groups such as ACCR (and its counterpart Market Forces) have taken up this tool more recently and lodged resolutions to Australian banks, utilities, oil and gas companies, insurers, and now the big miners, asking for improved disclosure and better management of climate risks.

What’s more, institutional investors are increasingly backing these requests. This latest resolution to Rio Tinto is also reportedly supported by key voting advisors ACSI and Regnan, as well as other major Australian super funds.

As a result, it marks a significant shift in investor culture in Australia, signalling an increased willingness to engage proactively and publicly on environmental, social and governance issues.

Compared with the US and UK, shareholders in Australia have more limited rights to bring resolutions to an AGM expressing their views or requesting that certain actions be undertaken by company management. Australian court decisions have upheld a strict division of powers between company management and shareholders. Nonbinding advisory resolutions on matters that interfere with company management are not permitted. This means shareholders must lodge a special resolution to change the company constitution to allow them to put forward an advisory resolution on a substantive matter such as climate change.

This is not only clunky and inefficient, but also acts as a significant deterrent for investors to support a substantive resolution with which they would otherwise concur. There are renewed calls for law reform, widely supported by institutional investors and also, increasingly, by some of the companies facing these resolutions, to change the law to allow for a more consistent and orderly approach in Australia.

Do these resolutions actually change behaviour?

From their brief history in Australia so far, it appears that shareholder resolutions on climate change, together with a range of other influences, do have the potential to drive change. Many Australian companies that have faced these resolutions so far have responded with significant improvements in climate risk disclosure and management.

Santos recently released its first Climate Change Report; AGL has developed a long term energy transition strategy; and BHP Billiton (which faced a similar resolution to Rio Tinto on its membership of industry associations in 2017) has announced its withdrawal from the World Coal Association and reviewed its other industry association memberships, including the MCA.

While these developments are undoubtedly the result of many factors – including technology and market developments, behind-the-scenes engagement with investors on climate risks, and increased pressure from financial institutions and regulators – it seems that shareholder resolutions can help to focus a company’s attention on ensuring its climate stance is defensible to shareholders. The impact of these resolutions in Australia may also be a function of their relative novelty compared with other jurisdictions such as the United States.




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This week’s resolution at Rio Tinto signals a coming of age for investor engagement on climate change in Australia. Shareholder resolutions have clearly become an important part of the toolbox for civil society in Australia seeking to influence corporate decision making on climate change.

As mainstream investors come on board with these resolutions, their potential impact is heightened considerably. For their part, Australian institutional investors seem to be increasingly willing to stand behind calls for better disclosure and management of climate risks by the companies in which they invest, including by forming new alliances and supporting the use of these more activist tools.

The ConversationIn a country with a relatively conservative approach to investor engagement, these are important cultural shifts. They offer promising signs that Australian businesses and investors are taking a more considered and proactive approach on climate risks.

Anita Foerster, Senior Research Fellow, University of Melbourne and Jacqueline Peel, Professor of Environmental and Climate Law, University of Melbourne

This article was originally published on The Conversation. Read the original article.