Crops, trees ‘to flourish’ in climate change – expert

The West Australian: One of the few upsides of global warming could be more trees and the prospect of higher crop yields for farmers, an expert said today. Andrew Ash, head of the Commonwealth Climate Adaptation program, said elevated concentrations of carbon dioxide, the gas responsible for global warming, had been shown to push up plant production and crop yield in field tests.

But it was just one positive in a sea of negatives, he warned an agriculture conference in Queensland.

Higher levels of CO2 improved both the photosynthesis and water efficiency of plants, Dr Ash said. He said the gas “increases wheat yield by 10 to 50 per cent” and increases “cotton biomass by 35 per cent” in trials in which the CO2 level is almost double its current rate of about 380 parts per million in the atmosphere….

But Dr Ash also pointed to dire predictions for the health of the Murray-Darling Basin as climate change took hold. “For each percentage point down in rainfall, there is a two to three per cent reduction in run-off,” he said.

This means anywhere between 10 and 25 per cent less water flowing into the already struggling basin. He also said the Roaring 40s which have delivered Southern Australia rain for many years were slowly becoming the “furious 50s” which meant rain would bypass Australia…