Is a 43% reduction in emissions enough?

A cold pot on the stove is static and predictable. When you boil water, it becomes more and more chaotic, boiling, bubbling and turning into steam. Climate works in much the same way. Increasing the amount of energy in the system increases the amount of chaos.

That characterizes the consequences of the climate crisis. More extreme, more chaotic, more unpredictable. Increased droughts, floods, cyclones and wildfires. “The climate crisis will be experienced in extreme events,” said Professor Lauren Rickards, co-leader of RMIT University’s Climate Change Transformation Research Program. “There’s more energy in the atmosphere, and everything is a little more unstable.”

The mechanisms underlying the climate crisis are known in great detail. However, the outcome cannot be predicted directly.One reason for this is the multiple bad outcomes (heat waves When drought When expansion of the range of crop-eating insects) may occur simultaneously.

Think of a farmer coping with drought. They were able to purchase fodder from places other than drought. However, when multiple droughts occur at the same time, there will be no place to buy fodder. “We lose a lot of our ability to cope,” Rickers says.

The more energy you lock into a system, the more chaos and unpredictability you have, and the more likely bad things can happen. We are moving further into the unknown.

Consider what scientists call a “tipping point”—a major event that disrupts an entire system. They are particularly concerned about the melting of the Greenland and West Antarctic ice sheets. world’s largest ice blockMelting them could raise sea levels by several meters in hundreds of years.We don’t know where this line lies, but scientists say I think it’s about 1.5 to 2 degrees. warmer than before the industrial revolution.

All warming raises both risks and uncertainties. “He decimal number 1 degree counts, measured in lives lost, livelihoods around the world, and the places we love,” says Baxter.

So why shoot at 1.5 (or 2) degrees?

both Political Goals, Not Scientific Goalsestablished by international conventions, says Baxter.

Dr Linden Ashcroft, a climate scientist at the University of Melbourne, said it was a limit that researchers in various fields, including ecosystems, human health and the climate system, said going above 2 degrees would make things worse. “And even a difference of 1.5 and 2 degrees is huge,” he says.

Can it be kept at 1.5 degrees at 43%?

If we want to keep warming below 1.5 degrees, we need to act quickly.the world is already 1.2 degrees hotter Since the industrial revolution. At the current pace, it will rise another 0.1-0.3 degrees every decade. That means, in the worst-case scenario, he could reach 1.5 degrees as early as 2030.

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Australia accounts for about 1% of global emissions.the world has a total “Carbon budget” – the maximum amount of greenhouse gases that can be emitted before exceeding 1.5 degrees of warmingIn early 2021, Researcher team It concluded that if Australia were to win 1% of its global budget, 3,521 megatonnes (million tonnes) of greenhouse gas emissions would remain before Australia’s share is exceeded. Not much, considering it emitted 4,239 megatonnes in the seven years from 2013 to 2020.

Our budget, our carbon bank account, is almost empty. To keep warming below 1.5 degrees, we need to cut greenhouse gases significantly. This can be seen in the following picture of the team that created the budget.

To get on track to limit warming to 2 degrees by 2030, we need to cut emissions by 50% from 2005 levels.

To keep temperatures below 1.5 degrees, we basically need to put the brakes on emissions now, reducing emissions by 74% by 2030 and going to net zero by 2035.

Baxter said: No matter how you calculate the numbers, it’s not. “

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Crucially, many climate scientists believe that deep cuts should be made sooner rather than later. Some sectors, such as aviation and steel, are very difficult to decarbonise. Low-hanging fruit issues like the power grid need to be tackled early, so we need to set aside time to consider how we can run our planes on renewable energy.

“43% is definitely better than nothing,” says Ashcroft. “But that’s not enough.”

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