EXPERT REACTION: 2017 among the three warmest years on record

The World Meteorological Organization has confirmed the last three years as the hottest on record just as we see dangerously high temperatures at the Australian Open.

A few years back scientists in NSW used wet-bulb temperature - the same process used to protect athletes during tennis championships - to estimate the limit of human survival in a hotter world. The limit of complete human anhilation was only 12 degrees.

The original estimates conducted by Stern in the United Kingdom estimated global impacts at smaller increments, for example, 0.5, 1, 2.5 and 4 degrees. Even at these small increases, the global impact meant more bushfires, collapse of the Amazon, ocean acidification, species extinction, famine and disease.

In a 2013 paper we estimated that developing nations aspiring to an Australian standard of living would emit enough greenhouse gases to greatly surpass 4 degrees. And yet some form of equality of consumption and production is needed for the whole world to negotiate a global brake on emissions. We can't even talk about this yet because the conversation in Australia is still mired in politics.

This is an issue that transcends politics, and remains just as urgent as nuclear weapons, rising political instability and terrorism. In fact, the same processes driving climate change are also driving many of Australia's social problems. Bushfire is just one symptom of a tangled and distorted system.

As long as we're distracted by short-termism, climate change is one issue that, like compound interest, will inevitably call in its debt. Our current leaders bequeath that debt to our children.

If some of our greatest athletes are challenged by the heat at the Australian Open in 2018, then think what a hotter world would mean for our most vulnerable in say, 10 years, 20 years, 30 years. I wonder whether we are any less culpable than the person who leaves a child in a hot car?

The WMO’s global findings will not be a surprise to people living in SA, Vic or NSW, who yet again are preparing to swelter through another run of 40-degree-plus days.

Extreme heat in summer is a new normal, particularly for urban populations. Sydney and other Australian cities need to urgently focus on ways to help people cope through extreme heat.

In Western Sydney our heat-mapping research has underpinned Penrith City Council’s ‘Cooling the City’ strategy, where climate adapted infrastructure, such as bus stops, are helping those without air-conditioned cars get around safely.

The record breaking warming despite neutral ENSO and La Niña is contributing to a spate of globally extreme fires- the bushfire risk situation is deteriorating and Australians remain poorly prepared. We need to urgently start adapting to this new reality.

Despite there being no boost from natural climate variability, such as an El Niño event, we've seen one of the three warmest years on record for the globe in 2017.

The Earth is now about 1°C warmer than it would be without human activities so we are well on the way to the Paris goal of 1.5°C unfortunately. Much stronger reductions in greenhouse gas emissions will be necessary if we are to meet the 1.5°C target. 

The impacts of climate change aren't just seen globally of course. In Australia we are seeing increases in the frequency and intensity of heatwaves, like the one we are currently experiencing in the southeast of the continent.

If we don't act on climate change we will see more heatwaves affecting Australia in future decades.