Scientists … project a rise in sea water levels and the loss of coastlines around the world. Small island chains … might entirely disappear under the ocean. Snow atop many of the world’s great mountain ranges is melting … More than one-sixth of
Scientists … project a rise in sea water levels and the loss of coastlines around the world. Small island chains … might entirely disappear under the ocean. Snow atop many of the world’s great mountain ranges is melting … More than one-sixth of the human race lives in mountain valleys and relies on the snow for irrigation, sanitation, and drinking water. Relocating nearly a billion people in less than forty years seems unfathomable.
-from The Third Industrial Revolution by Jeremy Rifkin
A few weeks ago I watched Jon Shenk’s documentary The Island President, a powerful film about former president Mohamed Nasheed’s fight to save his country from rising sea levels. For me, this film was a reminder of an issue that has – largely – faded into the background of our global consciousness (at least where mainstream media is concerned). And while we are growing less interested, climate change remains a threat. Though it may seem somewhat dramatic, I believe Jeremy Rifkin is correct when he writes that global warming is “the greatest challenge to ever face the human race.”[i] If anything is deserving of dramatic language, it is climate change.
For a couple of weeks I have been attempting to understand this challenge. This post (part one of two) is an effort to clarify a number of things: what global warming is, what it means for our planet, and why there is still resistance to the idea of human-caused climate change. (I apologise if this week’s post seems obvious or repetitive, however I believe there is value in getting the facts straight.) In my next post I will investigate how we should be responding to climate change as well as how we are actually responding (our actual response turns out to be a little more hopeful than I had originally thought it would be).
It should be noted that in both this post and the one to follow I have relied on three major sources for information. The first is Jeremy Rifkin’s book The Third Industrial Revolution. Second, the UN’s summary of the IPCC’s (Intergovernmental Panel on Climate Change) Fifth Assessment report. And finally Alex Magnin’s series of sustainability videos available on YouTube (wonderfully clear and beautifully drawn).
What is global warming (climate change)?
To understand global warming we first have to understand that Earth experiences regular and natural climate cycles. We know that over the last 400,000 years, for example, there have been four major climate cycles, all with similar ups and downs.[ii] These repetitive variations in climate are sustainable: that is, they occur as part of a delicate balance of rhythms that make our planet conducive to life.[iii] One of the reasons Earth is able to support life is the presence of gasses (such as carbon dioxide and methane) in its atmosphere that trap heat and warm the planet.[iv] For hundreds of thousands of years these gasses have existed in our atmosphere in sustainable quantities, resulting in a climate that shifts back and forth slightly but remains supportive of life. Carbon dioxide, methane and other greenhouse gasses are, in fact, largely responsible for our existence.
The second thing we have to understand is that the safe level of greenhouse gasses in the atmosphere has increased dramatically since about 1960.[v] Warming since then cannot be explained by the Earth’s natural cycles – the (at least) 400,000 year old pattern has changed, and is no longer sustainable.[vi] The cause of this unnaturally large amount of greenhouse gas and the subsequent rise in the Earth’s temperature is – according to a majority of scientists – us. More specifically our recent enthusiasm (since the Industrial Revolution) for burning fossil fuels that release huge amounts of carbon dioxide into the atmosphere.[vii] The IPCC, in its Fifth Assessment of global warming which will be finalised this month, states that “the human influence on the climate system is clear.”[viii] Less clear is exactly is exactly how devastating the effects of this influence will be.
What does climate change mean for our planet?
At the moment scientists are predicting a rise in temperature of at least three degrees Celsius by the end of the century.[ix] According to Rifkin, the most serious aspect of global warming is the effect it has on the Earth’s water cycle. A change in temperature leads to an increase in the capacity of the atmosphere to hold water. This in turn changes the way water is distributed on Earth: in other words, global warming effects how often and how much it rains. Scientists believe global warming will cause rainstorms to be shorter and less frequent but much heavier, resulting in an increase in both floods and droughts.[x]
We are already starting to experience some of the effects of climate change. Longer and hotter summers mean more bushfires in certain regions of Australia, for example, and the number of serious hurricanes has doubled over the past forty years.[xi] Ocean levels are expected to rise more than 1 metre by the end of the 21st century due to the rapid melting of Antarctic ice – devastating news for island nations like Kiribati and the Maldives that sit just a few metres above sea level.[xii]
Predic