"Such blooms are a regular feature of Australian inland waterways and are increasing due to nutrient run-off, reduced river flows and climate change."
So while climate change (i.e., warming in targeted areas) doesn't help, it's more of the final nail in a series of nails we've been driving into Mother Nature's heart.
The idea we could be so negligent and abusive of our own home without repercussions is a great narrative for profits, but not so good for our home.