Why a two degree Celsius increase in the global average temperature is a big deal

Elizabeth May

The International Energy Agency is warning that shooting past two degrees Celsius average global temperature will have “dire consequences.” And the World Bank is talking about 3.5 degrees of warming as being “devastating.” These are not environmental agencies. They are conservative, economically-oriented institutions. They are “establishment” with a capital E. Their language is increasingly alarmed, and yet nothing happens.

I think part of the problem is that even when experts understand the peril in which all human society is placed, those who are alarmed are afraid to sound “alarmist.” Translating the impact of two degrees, 3.5 degrees, and even higher levels of warming into language that is clear and unequivocal is not a project for the faint of heart. Let me try to explain two key factors in the IEA, World Bank, IPCC, and other projections.

The first is that these agencies do not yet say there is no chance of avoiding the two degree of warming threat which all countries, including Canada, and Prime Minister Stephen Harper personally in Copenhagen in 2009, have pledged to avoid. What is said is that if the collectivity of nations maintain current plans for climate action, the total impact is to allow greenhouse gases to continue to rise. On current policy trajectories, we fail miserably in our stated objectives. Only with the kind of urgent and comprehensive economic transitions undergone by nations at war can we avoid over-shooting two degrees. And even then, we are not guaranteed success.

Two degrees global average temperature warming is not a goal. It is to be avoided. It represents a level of human-caused climate impact which ensures dangerous levels of climatic destabilization. Many low-lying island states point out that at two degrees, they will be permanently inundated.

Yet, in a country like Canada that experiences minus 40 Celsius in winter and plus 40 Celsius in summer, it does not sound like a lot. Our failure to stress context allows the number to become meaningless. Only when it is explained that the difference between global average temperature today and in the last Ice Age was only five degrees Celsius does it become clear that two degrees global average temperature change is huge.

The second is to translate two degrees, three degrees and so on global average temperature into a language that actually says what it means. Given that two degrees is dangerous, what do words like “dire,” “devastating,” and “catastrophic” mean?

To understand a worst case-scenario for humanity due to the climate crisis, you need to understand the concept of positive feedback loops. Burning forests release carbon, warming the Earth faster to cause more forest fires. Melting Arctic ice reduces the albedo effect that bounced the sun’s heat back to the atmosphere. Without ice, the sun’s heat is absorbed in dark ocean water, warming the ocean faster, melting ice faster, further reducing the ice cover.

As the warming climate melts the permafrost, methane, a powerful greenhouse gas, is released from what was once locked away. The methane further warms the earth, melting more permafrost and releasing more methane. These are examples of positive feedback loops, of which there are many more.

At some point in the human-caused surge in atmospheric greenhouse gases, we could unleash an unstoppable release of warming forces. This is called “runaway global warming.” The worst case scenario is that the planet becomes more like Venus—uninhabitable for all, but some microbes or bacteria able to cope in high temperatures. I don’t think it will come to complete extinction of humankind and most of our fellow travellers on Planet Earth.

However, it is hard to imagine how human societies, civilization itself, could survive the loss of the Western Antarctic ice sheet, leading to the flooding of all coastal cities; or permanent states of drought in food producing regions; or tens of millions of refugees fleeing famine and floods. These are not far-fetched events. They could occur in the lifetimes of our own children.

In Ronald Wright’s best-seller, A Short History of Progress, he reviewed a litany of once magnificent civilizations that snuffed themselves out. One line, a piece of graffiti Wright repeated, sums it up: “every time history repeats itself, the price goes up.”

Wright was interviewed recently for a brilliant piece by Chris Hedges (“The Myth of Human Progress,” truthdig.com, Jan. 13, 2013). Wright pondered our inability to address an impending disaster that could eliminate us from the face of the Earth. “We’re Ice Age hunters with a shave and a suit,” said Wright. “We are not good long-term thinkers.”

So next time you read that the International Energy Agency thinks we could face “dire” consequences and the World Bank warns impacts could be “devastating,” don’t yawn and turn the page. Find a way to join the movement demanding a planned, aggressive transition away from our dependency on fossil fuels.

We have a profound moral obligation to protect our children and their children from what many increasingly see as unavoidable. Not unavoidable because we lack the ingenuity, technology and creativity to avoid two degrees; we could do so and experience an increasingly healthy economy. Those who believe it is unavoidable simply cannot believe we will bother to try. Let’s make 2013 the year when it all turns around, when the community of nations decides to give humankind a future as well as a short history of progress.

Green Party Leader Elizabeth May represents Saanich-Gulf Islands, B.C.
Originally printed  in the Hill Times.