Health experts, scientists and economists have rung the alarm bells on climate change for years but powerful interests in parliament, the media and business have paralysed climate change policy.

Climate change is undeniably a critical health issue, even more so for an ecologically fragile continent like Australia.

The science on climate change is clear. Report after report by the United Nations’ Intergovernmental Panel on Climate Change states that global warming is “unequivocal” and there is overwhelming evidence for human-made global warming.

The IPCC reports are based on a rigorous assessment of the published and peer-reviewed research of more than 1250 expert authors from 30 countries.

Climate change is already a health emergency.

A report by 150 experts from 27 universities and institutions including the World Health Organization and the World Bank set out the impacts of global warming on health in stark terms late last year.

“A rapidly changing climate has dire implications for every aspect of human life, exposing vulnerable populations to extremes of weather, altering patterns of infectious disease, and compromising food security, safe drinking water and clean air,” it said.

“We cannot delay action on climate change. We cannot sleepwalk through this health emergency any longer,” said Tedros Adhanom Ghebreyesus, the WHO director-general.

The last four years have seen the highest average temperatures globally since records began in the 19th century. Nine of the 10 warmest years on record in Australia have occurred since 2005.

The economic consequences of climate change are also well documented.

In 2006, Sir Nicholas Stern, a former chief economist at the World Bank and British Treasury warned that unless we invest one per cent of global GDP per annum – he later upped it to two per cent – in measures to prevent climate change, it would cost us 20 per cent of global GDP.

The 2008 Garnaut Climate Change Review warned that climate change would be an economic disaster for Australian agriculture. By 2100, irrigated agriculture in the Murray–Darling basin would decline by 92 per cent, it found.

In March this year, Guy Debelle, the deputy governor of the Reserve Bank of Australia, warned of the growing risk of climate change to the Australian economy.

Despite all these warnings, the scientific evidence and the annual manifestation of global warming in record temperatures, worsening droughts, wildfires and rising sea levels, Australia has failed to conceive and implement a coherent climate change policy.