Climate Action Merribek: people in Brunswick, Coburg, Fawkner and Glenroy wanting action on climate change

Is Moreland prepared for a mega-drought?

October 31, 2020 at 11:08 am John Englart 1 comment

Drought stress on wetlands

New research from the University of Queensland suggests that Mega-droughts – droughts that last two decades or longer – are tipped to increase thanks to climate change.

Professor Hamish McGowan, the leading author of the new study, said the findings suggested climate change would lead to increased water scarcity, reduced winter snow cover, more frequent bushfires and wind erosion. The research looked at geological records from the Eemian Period – 129,000 to 116,000 years ago – when temperature were similar to or slightly higher than today.

Mega droughts will change how we use water, and also have implications for food security both locally and nationally.

“We found that, in the past, a similar amount of warming has been associated with mega-drought conditions all over south eastern Australia,” Professor McGowan said. “These drier conditions prevailed for centuries, sometimes for more than 1000 years, with El Niño events most likely increasing their severity.”

“The Eemian Period is the most recent in Earth’s history when global temperatures were similar, or possibly slightly warmer than present,” Professor McGowan said.

“The ‘warmth’ of that period was in response to orbital forcing, the effect on climate of slow changes in the tilt of the Earth’s axis and shape of the Earth’s orbit around the sun.

“In modern times, heating is being caused by high concentrations of greenhouse gases, though this period is still a good analogue for our current-to-near-future climate predictions.”

The millenial drought will be seen as just a minor precursor to these large scale drought events.

Murray-Darling Basin is already suffereing substantial water stress from inadequate environmental flows and mismanagement of water allocations over previous decades.

The researchers conclude from the past climate record they have put together that

“indicates that southeast Australia will likely continue to experience interannual to interdecadal wet–dry cycles driven by teleconnections and solar variability at least until current global warming exceeds Eemian temperatures, possibly within the next decade. However, our record also shows that in a warm interglacial climate such as today or near future, there is risk of multi-centennial periods of less effective precipitation (mega-droughts), initiated by natural variability. Should such prolonged periods of drier conditions occur again, then they may be reinforced by anthropogenic global warming, thereby increasing their severity.”

So what does it mean for us here in inner city Moreland?

It is so important we get our water sensitive urban design in place.

We need to capture and store the stormwater runoff from all our hard surfaces to retain for environmental use.

During the millenial drought Moreland Council put 44 gallon drums beside many park trees to drip feed water to keep them alive. We are likely to need to do this again.

Those local shopping centre upgrades with those funny little gardens with the guttering channelling water to them? That is part of water sensitive urban design.

Residents should consider installation of rain-water tanks to capture roof runoff, if they have not already done so.

Moreland Council’s Water sensitive urban design planning requirements will become even more important.

We also need to build our local food growing resilience. With agricultural production in rural Australia squeezed by drought conditions our urban farming with CERES, Joe’s Market Garden, Fawkner Food Bowls, and hopefully other ventures, becomes far more critical and enhances our local community resilience and food security.

The Moreland Council Food System Strategy will need to be revisited and refined further to meet the challenges of mega-drought conditions.

Supporting Local Food production will build community resilience.

We may not be able to avoid mega-droughts, but we can all reduce our own emissions, and advocate for businesses and government to reduce emissions through transition plans.

We can start preparing and adapting for our warming climate, which will be drier, hotter and require far better management of water and our environment.

References:

• Media release via Australian Science Media Centre, 30 October 2020 – Expect more mega-droughts, https://www.scimex.org/newsfeed/expect-more-mega-droughts
• McGowan, H., Campbell, M., Callow, J.N. et al. Evidence of wet-dry cycles and mega-droughts in the Eemian climate of southeast Australia. Sci Rep 10, 18000 (2020).DOI https://doi.org/10.1038/s41598-020-75071-z

Entry filed under: climate change info, food security. Tags: drought, food security, stormwater.