Over the past 20 months we have had to confront and address a rolling series of challenges; from managing outbreaks to implementing the fastest vaccination rollout we have ever attempted.

We have learned a lot about our health system in the process.

Now we need to apply those lessons to a much bigger challenge: climate change. COVID-19 has highlighted the vulnerabilities of our healthcare system during a health crisis.

The climate crisis is a health crisis. Unlike COVID, the climate crisis will be ongoing.

Only a few months before the international borders started to shut, the Black Summer Bushfires burned through more than 5.5 million hectares of Australia's eastern states.

Our cities and towns were blanketed in smoke for weeks, reaching even those who were far-removed from the fires, marking our worst bushfire season yet.

Alarmingly, we must expect similar or even worse bushfire seasons will occur in the future because of climate change.

As a respiratory physician, I am at the front line, treating people who are suffering climate-related illness today.

This problem is not something that might happen - it is here.

There is evidence of poorer air quality, increased allergen exposure, temperature extremes, floods, compromised food supplies and increased mental illness. I have no doubt respiratory physicians across the east shared the same experience.

In the south-east of NSW and the Riverina, the rate of respiratory presentations to emergency departments grew significantly. Those with pre-existing respiratory illnesses, such as asthma, suffered greatly.

These are real people being affected by climate change related illnesses, right now. With extreme weather events predicted to worsen, scenarios like these will only become more common.

New Zealanders have likewise had unexpected floods and fires as their environment changes.

The increase in patients presenting as a result of extreme weather events will undoubtedly put pressure on the health system, just as the waves of COVID-19 patients have done over the past two years.

We cannot expect our health system to deliver more without something giving way.

At the national level however, climate action has stalled. Climate change is not mentioned in Australia's Long Term National Health Plan, nor is it listed as a national health priority. Australia's Nationally Determined Contribution under the Paris Agreement does not consider health implications of climate change.

Imagine - how differently might we approach climate change if it were a disease?

We would have the $20 billion Medical Research Future Fund to research prevention, innovation, and treatment.

We would have a national strategy to reduce mortality and morbidity, and prevent illness.

We would be investigating where the vulnerabilities of the health system are and how we can improve patient outcomes. This failure of imagination needs to be addressed because everyday citizens are paying a price.

The health impacts of climate change go far beyond those caused by the bushfires.

Besides worsening extreme heat events, floods and droughts have significant health impacts too, including heat stress, cardiovascular disease, and psychological stress, as well as flow-on impacts from diminishing water quality and food security.

The fires themselves may be over for now, but one thought lingers: Are we prepared for the increasing impacts climate change will have on health? No, we aren't.

We will, again, be on the front line.

Health workers' roles as 'first responders' to climate change is a challenging reality but also an opportunity.

As health professionals, every single one of us has sworn an oath to protect and preserve human life to the best of our ability.

We can advocate for changes now to avoid the otherwise inevitable pressure that will wear down healthcare systems to ensure that we can continue to protect the health of patients.

Decisive action on climate change will save thousands from climate-related illness, and even death.

Prime Minister Scott Morrison addressed the COP26 climate summit to announce his emissions commitments, but 2050 is too late to reach net-zero.

The longer we wait to transition to net-zero emissions across all economic sectors, the higher the toll of climate impacts on our health and health systems and the harder it will be to turn things around.

Climate change is happening now. The health system needs to prepare for the impacts that are already locked in.

Together, we urgently need a climate change and health strategy.

We 'flattened the curve' with COVID, and now we must do the same with climate change.

We need to cut our emissions now to avoid the worst impacts of climate change - not only to the environment, but to our health and wellbeing.