Day Zero — when water supplies run dry — is approaching in Australia and around the world

Spring 2019 was the driest season in 120 years for Australia, according to the country's Bureau of Meteorology. It has so far been followed up by a nearly equally dry summer with some of the hottest temperatures on record. That trend is likely to continue as the earth continues to get warmer, and it carries with it a pressing concern: a water crisis. As lakes are rivers start to dry up, those living in the rural interior of the massive island continent are already finding themselves rationing water just to survive, according to a report in the New York Times — and Australia's water crisis likely to only get worse.

This spring was the canary in the coalmine for Australians. The heat alone was enough to run the water reservoirs in some towns completely dry, leaving some citizens without running water. It forced people to ration their access by taking fewer showers, leaving gardens to die and dirty dishes and clothes to pile up without the necessary resource to clean them. But now that the fire season has started in the country and gotten off to a blazing start with dozens of out of control flames threatening hundreds of thousands of homes, the country is being pushed to the point of crisis. According to a report from Agence France-Presse, dozens of rural communities are already preparing themselves for Day Zero — the moment when water is turned off entirely. Unlike cities on the coast of the country, which can convert seawater into serviceable drinking water, there are not alternatives available for cities sitting in the middle of Australia watching water sources run dry. As fires continue to burn, towns have to make a choice between allowing citizens to continue accessing rations of their water reserves or using it to douse approaching flames. The situation is untenable at best and could leave large portions of the country completely uninhabitable.

It's not as if the current situation was unpredictable. Climate Council, a nonprofit organization that provides information on climate change to the Australian public, issued a report last year highlighting the gradual damage that climate change has wrought on the country. It found that droughts have become more common and soil moisture has decreased, resulting in less productive crops. Hotter temperatures and a lack of rainfall — as much as a 25 percent drop — has also led to streams, rivers, lakes and dams running dry. Western Australia in particular has seen a 50 percent decline in streamflow since the 1990s, according to the study. According to a report from the Guardian earlier this year, Australia's longest river, the Murray, has been severely affected by this sudden lack of rainwater — shrinking to just 910 gigalitres (GL) entering the system in the past 12 months when its annual average is 5,000 GL. Similarly, Macquarie River in New South Wales has seen a massive drop off in water inflow, going from 1,448 GL annually to just 97 GL in the past two years.

These changes have been happening gradually — albeit not so gradually that people haven't taken notice —but are now occurring more drastically. The result is quite dire, particularly for rural farming and Indigenous communities that have made their homes in regions of the country experiencing water shortages. According to a report issued by WaterNSW — the New South Wales Government-owned water services company — if trends continue, the Lachlan River is projected to completely run dry by March 2020. That would leave towns in the central western parts of Australia without any reliable source of water. Border rivers are projected to become baren by September 2020, and northern towns relying on water from lakes systems and the Gwydir River could be cut off by March 2021. Even the city of Sydney, which houses more than five million Australians, could face a water crisis by October 2021 if the Nepean River ends up dry.

While the situation in Australia is pressing right now, it will be far from the only place to experience water shortages and impending crisis because of climate change. The idea of Day Zero looms for as much as one quarter of the world. A report from the World Resources Institute projects that as many as 255 million people currently live in cities that are at risk of experiencing a water crisis. That number is only expected to grow as global temperatures increase and extreme weather events like devastating droughts and land-destroying wildfires carry on for longer than expected. The report projects that nearly half a billion people, living across 45 major cities around the world, will be in high-stress areas that could face the reality of water shortages. These situations would only be exacerbated by recent findings that suggest our global water supplies are shrinking.

It may seem paradoxical that we are both seeing our water supplies dry up while some regions are also experiencing heavy and unmanageable levels of rainfall, but the fact is that dramatic weather events like these put more stress on our systems because they happen in a less predictable and manageable fashion. Water supplies like rivers and lakes require consistent levels of rainfall to prevent flooding from excess water and to keep the water source from drying out. It is entirely possible — in fact, it appears to be the case — that the planet will continue to experience extreme weather events like massive downpours and devastating droughts, both of which result in their own unique challenges for regions that face these wild and unpredictable swings.

As Australian towns face down Day Zero, so too have cities across the world. Cape Town, South Africa came within three months of a Day Zero event last year. Sao Paulo, Brazil was just 20 days away from its 22 million residents being without access to water in 2015. We are, as a civilization, on the brink of massive devastation caused by global warming, and it could come much sooner than the projections that say the worst will start happening in 2050 and beyond. In the next decade, you may go to fill a cup with tap water and find that nothing comes out. Day Zero may be only days away for some and when that day does come, there isn't a clear path back from the brink.