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ClimateChange_Stier_sound.pptxClimate Change What every designer should know.
This is a short presentation covering climate change fundamentals for design students and professionals. Climate change is an important topic for designers to be aware of and responsive to, because designers help create the world we live in. The choices designers make, in what they make, how its made, what its made of, how its used, and what happens to it after it’s disposed of, can impact large numbers of people and the environment. This is what you need to know.
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Our planet’s climate is controlled by its atmosphere. You can see our atmosphere isn’t very big. It’s a thin protective coating stretched over the earth’s surface. But that thin protective coating is surprisingly important. Without it, our planet would have no life whatsoever. Its surface would be as barren and freezing as the moon you see in the background. A healthy atmosphere is a precondition of life.
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Our planet has had a relatively stable and predictable climate for much of the last 10,000 years. It is no accident that agriculture began within this time period, a period characterized by relative peace and stable civilizations.
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The climate has been so stable, we tend to completely ignore it and take it for granted, not even being aware how much we rely upon it. But we rely on a stable, predictable, and moderate climate for such basic and vital activities as growing food, placing and designing settlements, and many, many other things.
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Here’s the entire volume of the earth’s atmosphere in comparison to the volume of the earth itself: again, not very big. Because the earth’s atmosphere is not very big, it is sensitive to relatively small changes. The composition and relative amounts of chemicals inside that little ball play a big role in how the atmosphere functions.
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Here’s the composition and relative amounts of the chemicals inside that little ball. You can see carbon dioxide is a relatively miniscule part of the earth’s atmosphere. Yet the relative amount of this molecule and a few others has an outsized role in controlling our planet’s climate, because of how these molecules react to sunlight.
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A large portion of the sun’s radiation is absorbed at the surface of the Earth. This heat then re-radiates back into the atmosphere, and then back out into space. The atmosphere holds on to some of that heat for a time, before it leaks back out into space.
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Some atmospheric molecules hold onto this heat longer than others, which is why they are known as “greenhouse gases”. Like a greenhouse in the sun, atmospheric gases like carbon dioxide hold on to the heat re-radiating from the earth for a relatively long time. This is why the earth’s climate is sensitive to small changes in the relative amounts of these particular molecules. There are other greenhouse gases besides carbon dioxide, such as methane, nitrous oxide, and water vapor. Some of these trap heat even more powerfully than carbon dioxide. These other GHGs are important. We are focusing on CO2 here, however, because of the greater relative quantity of CO2 being released into the atmosphere from human activities.
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Carbon dioxide concentrations in the atmosphere are measured in parts per million, and you can see that CO2 concentrations have been rising steadily over the last several decades. (The line is squiggly by the way, because the concentration of CO2 varies during each year, dropping slightly when it’s summer in the northern hemisphere, when plants are growing and fixing carbon dioxide into their tissues.)
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Since carbon dioxide is good at holding on to heat, global average temperatures rise along with atmospheric CO2 concentrations. You can see that very tight coupling in this graph covering the last 400,000 years of the Earth’s history. Spend some time understanding this graph, because this is the real story. The blue line is CO2 levels over time, the red line is temperature. The red line closely shadows the blue line with a slight delay. In other words, when carbon dioxide levels in the atmosphere go up, global average temperatures soon follow. On the far right of the graph, you can see that atmospheric CO2 concentrations are now way above historical highs. What do you think global average temperatures are going to do?
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We can see the first sign of this trend in recent temperature patterns. The top 10 warmest years on record have all been since 1998. Climate change is already happening. We have already destabilized the planet’s climate to an extent.
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The remaining uncertainties mainly concern the future expected magnitude of the effect: e.g., whether average global temperatures will increase by "just" 1.5 degrees Centigrade or by 5 degrees Centigrade over the next century. Those numbers may not sound like a big deal, until one reflects that average global temperatures were "only" 5 degrees cooler at the height of the last Ice Age.
- Jared Diamond
Here’s how Jared Diamond, the author of this week’s reading, puts it: “The remaining uncertainties mainly concern the future expected magnitude of the effect: e.g., whether average global temperatures will increase by "just" 1.5 degrees Centigrade or by 5 degrees Centigrade over the next century. Those numbers may not sound like a big deal, until one reflects that average global temperatures were "only" 5 degrees cooler at the height of the last Ice Age.”
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Global warming is related to but different than climate change.
The Earth’s climate is complicated: not every place will consistently get warmer. Some places will get colder (wetter, drier, etc.).
An increase in average global temperature results in increased variability in climate and greater climate extremes (i.e., climate change).
Global warming vs. climate change
A few other important things to mention. First, global warming is related to but different than climate change. An increase in human-caused GHGs causes global warming (i.e., an increase in the average global temperature), but this does not mean every place on Earth is simply getting warmer. Because the Earth's climate is complicated, an increase in average global temperature results in increased variability in climate and greater climate extremes (i.e., climate change). Some places get warmer, while some get colder, some drier, etc. Don’t let the phrase “global warming” confuse you. Climate changes means the climate is no longer relatively moderate and predictable.
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Weather is day-to-day change in the
atmosphere (e.g., precipitation, wind, etc.).
Climate is atmospheric conditions prevailing in
an area over a long period of time.
Climate change vs. weather
Also, don’t let daily weather confuse you. Weather is day-to-day changes in the atmosphere (e.g., precipitation, wind, etc.). Climate is atmospheric conditions prevailing in
an area over a long period of time. Don’t let the weather confuse you about broader trends happening to the climate.
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Sources and sinks
Other concepts that are helpful to know are sources and sinks. Atmospheric concentrations of GHGs are determined by the balance between sources and sinks. Sources are emissions of GHGs from human activities and natural systems. Sinks are the removal of GHGs from the atmosphere, either by conversion to a different chemical compound or long-term storage outside of the atmosphere. This is an illustration to help you visualize how this happens with carbon, known as the carbon cycle. Yellow numbers are natural fluxes in carbon, red numbers are human contributions, and all numbers are in gigatons (billions of tons of carbon). At the broadest level, you can see here our influence on the global carbon cycle. Humans are very active in doing two things relevant to the carbon cycle. First, through energy development, we are busy transforming that very large sink of fossil carbon in the lower left into an atmospheric source. Second, through agricultural and settlement practices, we are also busy transforming that plant and soil carbon sink in the upper left into an atmospheric source.
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Anthropogenic GHGs by human activity
It’s also good to be aware of which human activities result in GHGs, and their relative contribution to the total emission of GHGs by people. A top level view would look something like this. You can see that the electricity used in buildings causes about one-quarter of our GHG emissions, manufacturing a bit more. And land use change – through deforestation and agricultural practices – results in another one-quarter of our emissions.
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As designers, we design things, whether these are consumer products, experiences, the plans for buildings, or the design of entire cities. Each of these designs has an associated negative or positive impact on the human emission of GHGs, and these things can be measured. A product’s GHG “footprint” is a measure of a product’s contribution to global warming through the emission of greenhouse gases. It measures the emission of greenhouse gases from each phase of a product’s life-cycle – from the acquisition of raw materials, to manufacturing and processing, packaging, distribution, retailing, use and disposal.
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As designers, we can influence how what we make, and what we even choose to work on, impacts the global climate. But we can do this only if we appreciate our atmosphere and the implications of climate change, are aware of our potential impact, and become empowered by the range of choices we actually have.
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Credits
Earth’s atmosphere from space: NASA
Volume of Earth’s atmosphere: Adam Nieman
Solar energy balance: NASA
Greenhouse carton: UC Berkeley
Agriculture: http://commons.wikimedia.org/wiki/File:Agriculture_(Primitive)_CNE-v1-p58-I.jpg
Top 10 warmest years: compiled from NOAA and NASA data
Anthropogenic GHG pie chart: http://www.manicore.com/anglais/documentation_a/greenhouse/evolution.html
Snow: www.englishexercises.org
Rain: 72ppi.us
Black shoes: http://www.colourbox.com/image/black-leather-shoes-on-black-isolated-background-image-3109053
Video game still: www.theverge.com
Blueprint: alexiasdesktop.com
Last image of Earth’s atmosphere: www.allsciencesites.com
© Sam Stier 2014
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