Westpac's decision to effectively rule out lending to the proposed giant Adani coal mine in Queensland has drawn praise from environmentalists but prompted the Turnbull government to dub the move "Pythonesque".

The bank on Friday released its updated position statement on climate change, stating Westpac had "long recognised that climate change is one of the most significant issues that will impact the long-term prosperity of our economy and way of life".

Westpac will aim to increase lending to "climate solutions" such as renewable energy and energy efficiency by two-thirds, from current levels of about $6 billion, to $10 billion by 2020 and quadruple it to $25 billion by 2030.

The bank, though, said it would not lend to any new coal project supplying power stations that fell below the top 15 per cent of global energy quality.