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In the past three weeks, tens of thousands of Australians have had to evacuate their homes after devastating floods struck the eastern part of the country.

Some regions experienced their worst flooding in decades, as torrential rain submerged residential areas, cut power lines and caused reservoirs to swell past the bursting point, resulting in tens of millions of dollars in damage.

New South Wales Premier Dominic Perrottet called the floods a “once-in-a-thousand-year event.”

But experts say climate change is fuelling an increase in extreme weather across Australia, threatening to make bushfires, floods and droughts more common.

A report published last month by the United Nations Environment Programme (UNEP) and GRID Arendal predicts that wildfires will become more frequent and intense, with a global increase of extreme fires by 50 per cent by the end of the century. The increase in wildfires renders land barren, which leads to increased run-off and, therefore, floods and, later, drought.

It’s a trend that is happening around the world, says Alvin Chandra, an expert in climate change adaptation with UNEP. And many countries, he warns, are not prepared.

We spoke with Chandra about the flooding in Australia and what states need to do to ready themselves for the new ‘climate normal’.

Globally, the number of flood-related catastrophes has more than doubled since 2000. Is Australia seeing a spike in flooding as well?

Alvin Chandra (AC): Scientists are united in the view that extreme flooding is becoming more prevalent in Australia, which can be attributed to warmer oceans that increase the amount of moisture moving from the sea to the atmosphere. This will most likely increase the intensity of extreme rainfall, extreme bushfires and extreme heatwaves.

The recent floods in Australia are some of the worst the country has ever experienced and have caused widespread devastation. To give just one example, Brisbane has experienced 80 per cent of its annual rainfall in just three days. These are the same communities where we saw massive bushfires in 2019 and 2020 which resulted in the loss of shrubs and trees setting the scene for extreme flooding.

Many people view climate change as a future problem. But has Australia’s climate already shifted?

AC: Australia – along with the Pacific Islands and Southeast Asia region ­– is in one of the most vulnerable regions [in the world to climate change]. Many of the communities dealing with this recent flooding have already had to deal with a range of cascading climate events in recent years. These droughts, bushfires, powerful storms and heat waves amplify the scientific evidence predicted by IPCC reports that we are already living in a changed climate.

UNEP: Beyond Australia, what parts of the world will be the hardest hit by extreme weather?

AC: Almost all parts of the world are experiencing a changed climate. When you [factor] in the human dimension of vulnerability, there are global hotspots in places such as West, Central and East Africa, South Asia, and Central and South America, small island developing states and the Arctic. Here we find that vulnerability is higher as [local populations] live in poverty. They have limited access to basic resources and there are often incidences of violent conflict.

There are also high levels of reliance on climate-sensitive livelihoods: many [people in these places] are small-holder farmers, pastoralists or live in fishing communities. In the past decade, human mortality from floods, droughts and storms was 15 times higher in these vulnerable regions compared to regions with lower vulnerabilities.  Vulnerability is also a factor of a government’s institutional and financial ability to respond. These communities are often at the receiving end of capacity gaps at multiple levels.

How many people globally are affected by extreme weather?

AC: Evidence suggests that some 85 per cent of the global population has already experienced extreme weather events. The recent IPCC report suggests that lives of at least 1 billion people could be made worse by climate change by 2050, where the vulnerable communities expect to suffer the worst impacts.