Bradfield's pipedream: irrigating Australia's deserts won't increase rainfall, new modelling shows
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Mittwoch, Oktober 4, 2023
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Our recently published research shows irrigating Australia’s deserts would not increase rainfall, contrary to a century of claims otherwise.
Key Points:
- Our recently published research shows irrigating Australia’s deserts would not increase rainfall, contrary to a century of claims otherwise.
- This provides a new argument against irrigating Australia’s deserts, in addition to critiques on economic and environmental grounds.
The Bradfield scheme
- The person most widely credited with the idea is John Bradfield, the civil engineer who designed the Sydney Harbour Bridge.
- The Queensland Liberal National Party campaigned on a policy to build a Bradfield-like scheme in the last state election.
- Despite our fascination with it, the Bradfield scheme has well-documented problems.
Would it increase rainfall?
- Would the Bradfield scheme increase rainfall in central Australia?
- In our model of the Bradfield-like scheme, we permanently filled the region around Kati Thanda-Lake Eyre with water.
- Our simulations showed no significant increase in rainfall.
Why no rain?
- But in our simulations, irrigating the surface led to evaporative cooling of the air.
- The colder air did not rise as much, and rainfall was suppressed.
- In our simulations, the water evaporated and was blown all over the Australian continent by wind.
- But our study shows no plausible engineering scheme would be capable of making it rain enough to do so.