Who cares if Earth warms up?
There are many arguments against action on climate change; Australians make a small contribution, it won't make any real difference, evidence that humans are causing the change in temperature is inconclusive, the world changes temperature all the time, etc.
In a narrow, self-interested way the “Australia is too small to matter” argument makes sense. However, if a loved one was morbidly obese and urgently had to lose weight, you wouldn't advise them to start dieting and exercise in month because what happens this month won't make any difference…would you? Australia punches well above our weight in world affairs and what we do does matter. Not as much as China, India and the US. However we can contribute and should.
I'm not sure it's possible to argue with someone who wilfully and blatantly disregards a consensus of 98% amongst scientists and specialists. Someone like Tony Abbott who believes in the big man in the sky, but not hard scientific data.
However there are those who think global warming is not such a big deal because Earth's temperature fluctuates naturally anyway, so how can it be a bad thing? I can understand, to an extent, this line of reasoning. After all, it is true in a superficial way, but some things need to be understood more broadly to understand how climate has impacted the development of human civilisation.
Human nations-populations of people that self-identify, have a shared history and culture, came into being based on some very specific factors. Principle among these was/is a population having access to food and natural resources. Throughout history, population centres formed in the most fertile places –river deltas (Nile, Amazon, Ganges) and those places where plentiful rainfall allowed cropping (Europe, sub-Saharan Africa, SE Asia). Figure 1 show's the regions on earth where rain-fed agriculture is a viable way to produce food.
As human society developed and transport technology became more efficient, regions that produce surpluses could trade them with the rest of the world; for example, areas that could be exploited for irrigation like Murray-Darling basin, the American Midwest with the Mississippi River became food production centres as well, and international trade has increased this effect. However, if we look at a world population distribution map, there is a very strong correlation between rainfall and where people live:
The density in South East Asia is incredible, something only possible by historical high rainfall and fertile land. Also, in India, Pakistan and China, this rainfall fed agriculture is supplemented vastly by annual glacier melts that feed their inland river systems.
Coming back to the question – why does it matter if the temperature changes?
Hotter earth means more energy, which means more frequent violent storms. The NAOO in the US believes that once a century storms will occur every two-three years with 1.5-2 degrees warming. Storms like that wipe out crops, destroy homes, ruin infrastructure, in places where the majority of human beings live.
It matters because if the temperature changes, the location and degree of rainfall will change as well, because of changed ocean and atmospheric conditions.
The UNEP reports that agriculture employees around 50% of people in South Asia, and 40% in the East. According to the World Bank, the vast majority of agricultural workers (for example, 86% of South Asia's 400 million rural poor) are employed in subsistence agriculture. Given that 70% of African food is produced by farmers at or close to subsistence level and in SE Asia the level is around 50%, any substantial change in yields will impact those populations hugely. Currently there are about 1.8 billion people in SE Asia and India. Sub-Saharan Africa has 930m people.
By definition, subsistence farming produces no or small surpluses. We live in a hungry world already. If yields drop too far, literally billions of people will face chronic food shortages.
So, who cares if the globe warms up? Well, all those hungry people will. Drought, storms and changing rainfall patterns will combine to drastically reduce crop yields. Massive storms will destroy homes and infrastructure. What will hundreds of millions of hungry, homeless people do?
What would you do, if your home was repeatedly blown away, and you couldn't feed your family? You'd find somewhere else to go, as will they. That will impact us indirectly, as our major trading partners are crippled by humanitarian crisis, war and internal unrest. What would you do if there was a place with benign weather, and plentiful food? You'd try to go there. Hence this will impact us directly, as millions of refugees try to come to Australia.
Our problem will be relatively tiny because we are a remote island however, in 2035 India and SE Asia will be home to 2 billion people. Major disruptions to food supply will cause conflict and internal unrest. This will make the region unliveable for many people. If 0.01% of the population of SE Asia and India attempt to come to Australia, we'll have 2 million trying to come here.
It's demonstrably clear that most Australians don't like boat people. Imagine if 2 million starving boat people wash up on our shores?
Now, the above may not happen, maybe it probably won't happen. But the cost of mitigating against it is far lower than the cost of having to deal with it. Battling global warming is exactly the same as taking out insurance on your car – it shouldn't be controversial.
Perhaps climate change is like driving a car towards a wall. If we hit the brakes hard, we'll just tap the wall and it won't be such a big deal. At present, for some reason, Australia is asking why should it slow down, nobody else is bothering?
Or perhaps it's like driving towards the edge of a high cliff. It doesn't matter if we roar of it at 150kmh or trickle over it at 1kmh. Once we reach that tipping point, where global warming is self-reinforcing, we're not going to stop until we hit the bottom.
Tim Butler holds a masters in international relations and international law, specialising in energy markets.