Tuesday, 2 October 2018
We have moved!
Sunshine Saved has moved to a new website, https://sunshinesaved.com/. Some of the material there is taken directly from this site, but the new site is the one that we will be using into the future.
Saturday, 30 December 2017
Other pollution - the scope of the problem
This post is a part of the Manitou Initiative series of articles.
For the sake of understanding the basic terrain of the really big sustainability problems, I think that it makes sense to lump together all of the pollution outside of greenhouse gases, so that the really big problems are: biodiversity and ecosystem loss, global climate change, and 'other' pollution. This is certainly a vast oversimplification, but a useful one. I say this because biodiversity loss and climate change are 'existential' threats, meaning that if we don't get these problems under control, we threaten the very future of humanity on the planet. In comparison, most of the other sorts of pollution that we create and are exposed to aren't a threat to humanity as a whole, even though they cause massive health problems and increased mortality to those who are most exposed. Every major pollution pathway ought to be improved to reduce the damage to human health and to the living environment, but with these essays' focus on sustainability we will mostly address the biodiversity and climate change effects of pollution.
A massive amount of the pollution that we produce is the byproducts of industrial processes and energy production. We want to build and drive cars, construct and heat homes, make medicines, kill weeds, and so on. Unfortunately all of this activity can produce substances that are toxic to human health, causing everything from lung disease to cancer, neurological problems to heart attacks. Many of these pollutants can be and often are cleaned up so that people are not exposed to them, but others are released into the air, water and earth.
Much of air pollution comes from burning, fossil fuels and wood for their energy, and the cooking involved in industrial processes to separate or refine the products that we need. The greatest threats from air pollution appear when people breathe this contaminated air. Being in the proximity of factories, or in the middle of cities that have smog problems, or poorly vented indoor cooking fires in developing countries, all contribute to increased mortality. Recent estimates of the effect of air pollution show that around 9 million extra deaths occur every year due to air pollution, mostly in the developing world. And for each death, there are many more who experience serious negative health outcomes. Cutting the use of fossil fuels, particularly coal, would make enormous strides for human health as well as reducing the release of greenhouse gases.
Water pollution is often caused by the dumping of wastes into waterways. Water is a great means of transporting wastes, whether they be from factories, or mines, or even human sewage. The problem comes when these wastes aren't remediated, neutralizing and removing the toxic parts before letting that water enter rivers, lakes and the oceans. Other wastes, known as non-point sources, fall into waterways after being distributed over a large area of land. Rain carries fertilizers and pesticides from farm fields, or oil and other chemicals from roadways, and puts those materials into streams and rivers. Slowing the movement of water over land, having healthy wetlands and vegetation along shores, all help to keep wastes from entering the water. Water pollution causes massive problems to human health, including the spread of disease from untreated sewage, or illness of all kinds from toxic chemicals that may get into the water we drink and use.
Finally there is the pollution of solid wastes, also known as garbage. It turns out that from a sustainability standpoint, non-toxic garbage isn't a grave concern. We are in no danger of running out of places to dig big holes in the ground where we can stack up and bury our discarded stuff. Throwing away so much material may be wasteful, which carries a significant impact in itself, but the disposal doesn't pose such large risks. The problems of physical wastes more often come when toxic materials leach into the surrounding soil and groundwater, or otherwise escape from a landfill. There are some particular problems that come from wastes like plastics, which are now accumulating but not breaking down out in the oceans, but these problems make for more localized threats to wildlife. There is much to be done to divert wastes from landfills, composting all the organic and food wastes, recycling more of the plastics and metals, and so on, but garbage is relatively far down the list as a sustainability concern.
Mostly I wanted to include this short essay to acknowledge all of the wastes that we produce that aren't directly tied to the big problems of climate change and biodiversity loss. Very early in any discussion of environmentally sound behavior the topics of these other sorts of pollution are going to come up. Very often the same solutions can address all of these problems at once. For instance, increasing the efficiency of our energy and resource use means less greenhouse gas emissions, less disturbance of ecosystems, and less production of other forms of pollution.
For the sake of understanding the basic terrain of the really big sustainability problems, I think that it makes sense to lump together all of the pollution outside of greenhouse gases, so that the really big problems are: biodiversity and ecosystem loss, global climate change, and 'other' pollution. This is certainly a vast oversimplification, but a useful one. I say this because biodiversity loss and climate change are 'existential' threats, meaning that if we don't get these problems under control, we threaten the very future of humanity on the planet. In comparison, most of the other sorts of pollution that we create and are exposed to aren't a threat to humanity as a whole, even though they cause massive health problems and increased mortality to those who are most exposed. Every major pollution pathway ought to be improved to reduce the damage to human health and to the living environment, but with these essays' focus on sustainability we will mostly address the biodiversity and climate change effects of pollution.
A massive amount of the pollution that we produce is the byproducts of industrial processes and energy production. We want to build and drive cars, construct and heat homes, make medicines, kill weeds, and so on. Unfortunately all of this activity can produce substances that are toxic to human health, causing everything from lung disease to cancer, neurological problems to heart attacks. Many of these pollutants can be and often are cleaned up so that people are not exposed to them, but others are released into the air, water and earth.
Much of air pollution comes from burning, fossil fuels and wood for their energy, and the cooking involved in industrial processes to separate or refine the products that we need. The greatest threats from air pollution appear when people breathe this contaminated air. Being in the proximity of factories, or in the middle of cities that have smog problems, or poorly vented indoor cooking fires in developing countries, all contribute to increased mortality. Recent estimates of the effect of air pollution show that around 9 million extra deaths occur every year due to air pollution, mostly in the developing world. And for each death, there are many more who experience serious negative health outcomes. Cutting the use of fossil fuels, particularly coal, would make enormous strides for human health as well as reducing the release of greenhouse gases.
Water pollution is often caused by the dumping of wastes into waterways. Water is a great means of transporting wastes, whether they be from factories, or mines, or even human sewage. The problem comes when these wastes aren't remediated, neutralizing and removing the toxic parts before letting that water enter rivers, lakes and the oceans. Other wastes, known as non-point sources, fall into waterways after being distributed over a large area of land. Rain carries fertilizers and pesticides from farm fields, or oil and other chemicals from roadways, and puts those materials into streams and rivers. Slowing the movement of water over land, having healthy wetlands and vegetation along shores, all help to keep wastes from entering the water. Water pollution causes massive problems to human health, including the spread of disease from untreated sewage, or illness of all kinds from toxic chemicals that may get into the water we drink and use.
Finally there is the pollution of solid wastes, also known as garbage. It turns out that from a sustainability standpoint, non-toxic garbage isn't a grave concern. We are in no danger of running out of places to dig big holes in the ground where we can stack up and bury our discarded stuff. Throwing away so much material may be wasteful, which carries a significant impact in itself, but the disposal doesn't pose such large risks. The problems of physical wastes more often come when toxic materials leach into the surrounding soil and groundwater, or otherwise escape from a landfill. There are some particular problems that come from wastes like plastics, which are now accumulating but not breaking down out in the oceans, but these problems make for more localized threats to wildlife. There is much to be done to divert wastes from landfills, composting all the organic and food wastes, recycling more of the plastics and metals, and so on, but garbage is relatively far down the list as a sustainability concern.
Mostly I wanted to include this short essay to acknowledge all of the wastes that we produce that aren't directly tied to the big problems of climate change and biodiversity loss. Very early in any discussion of environmentally sound behavior the topics of these other sorts of pollution are going to come up. Very often the same solutions can address all of these problems at once. For instance, increasing the efficiency of our energy and resource use means less greenhouse gas emissions, less disturbance of ecosystems, and less production of other forms of pollution.
Thursday, 14 December 2017
What can a person actually do to live sustainably? An introduction.
This post is a part of the Manitou Initiative series of articles.
When thinking about solving the problems of sustainability, or any other complex global issue for that matter, it is easy to feel overwhelmed, even helpless. The problems are so large that one wonders whether one person can even have an impact. Don't despair, there is much that you can do. I recommend that you focus on things that you are passionate about, those that you can stick with over time, and those that can make the biggest impact. Don't tie yourself up in knots of guilt, or make changes to your life that are going to make you miserable, as that isn't going to be productive. What we really need to do is to rally the support of whole societies, and one of the ways of doing that is to show naysayers that with sustainability you can 'have your cake and eat it too'. This doesn't mean that we can all live in mansions and drive massive gas guzzling cars, but we could all have homes that are wonderful to live in with readily available transport to get everywhere we need to go. We also need to accept that moving humanity to a sustainable trajectory takes time, with the results taking years or even decades. I personally am putting together a 15 year sustainability plan for my family (to be linked once fully written up).
Just as we must admit that it will be a long road, we are also all at different places upon that path. Someone who is just thinking about sustainability for the first time might be able to dramatically reduce their personal footprint by making those changes that constitute the 'low hanging fruit'. For someone who has already taken many steps to reduce their own impact, their goal could instead be to convince others to improve their own practices, be it friends and family, or the businesses and government that provide us with our goods and services. People also have different means to act. If you are a renter who works long hours just to make ends meet, it may be harder to make major changes to your behavior than for someone with more time and resources at their disposal. The important thing is that each of us who cares about sustainability and the future of our world acts, and does what they can.
The details to follow about the scope of what must be done are daunting, so I want to mention just a few promising trends. Though we are currently using too much land and releasing too many greenhouse gases, there are technologies coming available that will help to solve many of the problems that earlier technologies have caused. For instance, in the realm of energy wind and solar are now the cheapest form of energy generation in some places, and both are growing exponentially while starting to displace fossil fuel use. New agricultural technology, such as 'precision farming', increases yields while reducing inputs and pollution. Technology can and will do some of the heavy lifting for us, but we still need a culture that will adopt the best of technologies and practices as quickly as possible.
Where are we now? Where do we need to get to?
To understand the basic numbers of sustainability, it helps to describe them at the level of the individual - you, or any person living a modern lifestyle in a rich country. The easiest way to do this is to start with the total amounts of emissions, energy and land use, and then divide that by the number of people (I've done a version of this for my own family's energy use here). This is then the average amount that is used on behalf of each person in a society. Roughly one third of that energy is personal consumption, from building and heating our homes, to driving our cars, to our food, clothes, and electronics. Another third is each person's portion of the energy used by businesses and organizations that provide us with goods and services - a part of the energy to keep the lights on at your hospital is being used on your behalf. Finally, everything that governments do is (at least in theory) on behalf of its citizens, so of all of the energy used to maintain roads or armies or the IRS, a chunk of that is for each and every one of us. We can then compare those numbers with the estimates that ecologists and other scientists can give us about what sorts of levels are actually sustainable. The gap between the status quo and the sustainable level shows us the work we need to do. There are three things that I want you to consider, total energy use, greenhouse gas emissions, and land use (we'll leave aside other resources such as water for the time-being).
Total energy use isn't actually something that we need to worry about for its own sake. If we had infinite clean energy, every person could use as much as they want. However, we don't live in this magical world, and there are greenhouse gas, pollution, and land use costs to all the energy that we use. Tracking energy use is relatively straightforward to do and is very linked to greenhouse gases and land use, and there are good records for it. In the US, the total consumption of energy per capita is about 230 kilowatt hours (kWh) per day. Each person's share is about 8 times as much energy as a typical house consumes in a day. Using energy much more wisely and efficiently could allow us, over time, to reduce this total by a factor of 3 or 4 times, down to perhaps 60 kWh per person per day.
Greenhouse gas production is tightly linked to total energy use, especially considering how much of our energy currently comes from fossil fuels. In 2017, the American per capita production of CO2e (carbon dioxide equivalents) is about 16 tons. The overall global average is 4 tons. The 2015 Paris Climate Accord, agreed upon by virtually every nation in the world, seeks to limit global warming to no more than 2 degrees Celsius. To accomplish this requires that we reduce global per capita emissions down to less than 2 tons CO2e per person. This means that we need to figure out how to reduce our emissions in rich countries down to 1/8, or 12%, of their current level. There is an enormous amount of work to do here.
In terms of land use, we need to have space for ourselves and to grow our agricultural and timber products, while at the same time leaving room for all of the non-human species that we share the planet with. With the human population closing in on 8 billion, there are only 5 acres per person of total land area. Humanity has now pushed into just about every nook and cranny of the planet, so we need to be good stewards of what we use. Of all that land, about 1/3 is uninhabitable desert and glacier, 1/3 is agricultural, 1/4 is forest, leaving 1/10 for everything else. Urban areas use about 1/100 of all land. Humanity is already using almost all of the prime territory for agriculture, and there is very little frontier left to grow into, especially since we want to preserve what natural spaces we have left. On top of that the world's population is still growing, expected to reach 10 billion by the end of the century. Put all together, we need to reduce our impacts so that we can provide for the needs of each person on less than 2 acres of land, an area the size of two football fields. This area needs to provide all of each person's food, as well as many of the other products that they use, wood, paper, leather, cotton, and so on. Optimally we would be cutting in half the amount of land that we are using to provide for each person's needs.
What can we do about it?
I'll go much more in depth on each of the following topics in further posts (each header will receive at least one post), but there are really three types of actions that a person can take that can improve sustainability, which are: reduce our own consumption of goods and services, take direct actions that improve sustainability, and to work to encourage others to do the same.
Personal consumption
-Housing and home energy use
-Food and diet
-Transport
-The stuff that we buy and own
-The services that we use
Personal direct action to improve sustainability
Personal clean energy production - such as rooftop solar
Career and work that directly promotes sustainability
Land stewardship
Improving the sustainability of others' actions
Influence others in your life on their sustainability practices
Volunteer with or donate to charities or non-profits that promote sustainability
Advocacy with governments and/or businesses to improve their sustainability practices
When thinking about solving the problems of sustainability, or any other complex global issue for that matter, it is easy to feel overwhelmed, even helpless. The problems are so large that one wonders whether one person can even have an impact. Don't despair, there is much that you can do. I recommend that you focus on things that you are passionate about, those that you can stick with over time, and those that can make the biggest impact. Don't tie yourself up in knots of guilt, or make changes to your life that are going to make you miserable, as that isn't going to be productive. What we really need to do is to rally the support of whole societies, and one of the ways of doing that is to show naysayers that with sustainability you can 'have your cake and eat it too'. This doesn't mean that we can all live in mansions and drive massive gas guzzling cars, but we could all have homes that are wonderful to live in with readily available transport to get everywhere we need to go. We also need to accept that moving humanity to a sustainable trajectory takes time, with the results taking years or even decades. I personally am putting together a 15 year sustainability plan for my family (to be linked once fully written up).
Just as we must admit that it will be a long road, we are also all at different places upon that path. Someone who is just thinking about sustainability for the first time might be able to dramatically reduce their personal footprint by making those changes that constitute the 'low hanging fruit'. For someone who has already taken many steps to reduce their own impact, their goal could instead be to convince others to improve their own practices, be it friends and family, or the businesses and government that provide us with our goods and services. People also have different means to act. If you are a renter who works long hours just to make ends meet, it may be harder to make major changes to your behavior than for someone with more time and resources at their disposal. The important thing is that each of us who cares about sustainability and the future of our world acts, and does what they can.
The details to follow about the scope of what must be done are daunting, so I want to mention just a few promising trends. Though we are currently using too much land and releasing too many greenhouse gases, there are technologies coming available that will help to solve many of the problems that earlier technologies have caused. For instance, in the realm of energy wind and solar are now the cheapest form of energy generation in some places, and both are growing exponentially while starting to displace fossil fuel use. New agricultural technology, such as 'precision farming', increases yields while reducing inputs and pollution. Technology can and will do some of the heavy lifting for us, but we still need a culture that will adopt the best of technologies and practices as quickly as possible.
Where are we now? Where do we need to get to?
To understand the basic numbers of sustainability, it helps to describe them at the level of the individual - you, or any person living a modern lifestyle in a rich country. The easiest way to do this is to start with the total amounts of emissions, energy and land use, and then divide that by the number of people (I've done a version of this for my own family's energy use here). This is then the average amount that is used on behalf of each person in a society. Roughly one third of that energy is personal consumption, from building and heating our homes, to driving our cars, to our food, clothes, and electronics. Another third is each person's portion of the energy used by businesses and organizations that provide us with goods and services - a part of the energy to keep the lights on at your hospital is being used on your behalf. Finally, everything that governments do is (at least in theory) on behalf of its citizens, so of all of the energy used to maintain roads or armies or the IRS, a chunk of that is for each and every one of us. We can then compare those numbers with the estimates that ecologists and other scientists can give us about what sorts of levels are actually sustainable. The gap between the status quo and the sustainable level shows us the work we need to do. There are three things that I want you to consider, total energy use, greenhouse gas emissions, and land use (we'll leave aside other resources such as water for the time-being).
Total energy use isn't actually something that we need to worry about for its own sake. If we had infinite clean energy, every person could use as much as they want. However, we don't live in this magical world, and there are greenhouse gas, pollution, and land use costs to all the energy that we use. Tracking energy use is relatively straightforward to do and is very linked to greenhouse gases and land use, and there are good records for it. In the US, the total consumption of energy per capita is about 230 kilowatt hours (kWh) per day. Each person's share is about 8 times as much energy as a typical house consumes in a day. Using energy much more wisely and efficiently could allow us, over time, to reduce this total by a factor of 3 or 4 times, down to perhaps 60 kWh per person per day.
Greenhouse gas production is tightly linked to total energy use, especially considering how much of our energy currently comes from fossil fuels. In 2017, the American per capita production of CO2e (carbon dioxide equivalents) is about 16 tons. The overall global average is 4 tons. The 2015 Paris Climate Accord, agreed upon by virtually every nation in the world, seeks to limit global warming to no more than 2 degrees Celsius. To accomplish this requires that we reduce global per capita emissions down to less than 2 tons CO2e per person. This means that we need to figure out how to reduce our emissions in rich countries down to 1/8, or 12%, of their current level. There is an enormous amount of work to do here.
In terms of land use, we need to have space for ourselves and to grow our agricultural and timber products, while at the same time leaving room for all of the non-human species that we share the planet with. With the human population closing in on 8 billion, there are only 5 acres per person of total land area. Humanity has now pushed into just about every nook and cranny of the planet, so we need to be good stewards of what we use. Of all that land, about 1/3 is uninhabitable desert and glacier, 1/3 is agricultural, 1/4 is forest, leaving 1/10 for everything else. Urban areas use about 1/100 of all land. Humanity is already using almost all of the prime territory for agriculture, and there is very little frontier left to grow into, especially since we want to preserve what natural spaces we have left. On top of that the world's population is still growing, expected to reach 10 billion by the end of the century. Put all together, we need to reduce our impacts so that we can provide for the needs of each person on less than 2 acres of land, an area the size of two football fields. This area needs to provide all of each person's food, as well as many of the other products that they use, wood, paper, leather, cotton, and so on. Optimally we would be cutting in half the amount of land that we are using to provide for each person's needs.
What can we do about it?
I'll go much more in depth on each of the following topics in further posts (each header will receive at least one post), but there are really three types of actions that a person can take that can improve sustainability, which are: reduce our own consumption of goods and services, take direct actions that improve sustainability, and to work to encourage others to do the same.
Personal consumption
-Housing and home energy use
-Food and diet
-Transport
-The stuff that we buy and own
-The services that we use
Personal direct action to improve sustainability
Personal clean energy production - such as rooftop solar
Career and work that directly promotes sustainability
Land stewardship
Improving the sustainability of others' actions
Influence others in your life on their sustainability practices
Volunteer with or donate to charities or non-profits that promote sustainability
Advocacy with governments and/or businesses to improve their sustainability practices
Tuesday, 28 November 2017
Loss of biodiversity - the scope of the problem
This post is a part of the Manitou Initiative series of articles.
A very quick version of the problem of biodiversity loss:
Ecosystems are groups of species that all live together in a certain area. There can be many thousands of species, and they constantly interact and rely on each other to maintain the integrity of the whole. Plants form the basis of the food chain, taking energy from the sun and turning it into living tissue. Different plants fill different niches, some as tall trees, as grass, as climbing vines, some dropping their leaves for the winter and others keeping them all year. There are animals eating plants, other animals eating those animals, fungi decomposing everything that dies to recycle nutrients and begin the growth anew. Micro-organisms are found by the trillions in every nook and cranny.
While some (myself included) could wax poetic about the grandeur of wild spaces, of the beauty of old growth forests, or the thought of herds of bison roaming the prairies, providing beauty is far from the only thing that ecosystems do for us. Critical to the very survival of humanity are all of the things that ecosystems do for us, often called ecosystem services. Intact ecosystems provide us with soil, food, water, medicine, wood and other plant fiber, they maintain climate and rainfall patterns, and more. To provide all of these functions that we hold so dear, ecosystems need to be maintained in a healthy state. There are innumerable instances where people's damaging of lands and waters led directly to massive problems in human society. Floods, soil erosion, desertification, wildfires, polluted water, can all be caused by poor management practices, and can threaten the very foundations of societies. In today's world, climate change is linked tightly with ecosystem damage, as poor forest management and poor agricultural practices are some of the main drivers of a warming planet. In terms of species extinction, it is estimated that current human practices are causing the rate of species extinction to be a thousand times higher than what it was before the modern age, and we are currently be losing thousands of species every single year.
People need to act now to preserve ecosystems and species. We know that ecosystems are resilient, but it is unclear how much abuse they can take before problems may spiral out of control. There is something called the precautionary principle that tells us that we shouldn't take dangerous actions when we are unsure of how risky they are. The cost of doing nothing could be absolutely immense, whereas if we act now to change 'business as usual', we know that this is likely to lead to great outcomes for both people and the planet. There will be some costs associated with making these changes, but the long-term benefits to saving ecosystems and species far outweigh the short-term benefits of massive scale clear-cut logging or agricultural practices that destroy the fertility of the soil.
A very quick version of the problem of biodiversity loss:
- The earth's ecosystems consist of the interconnected webs of species (plants, animals, fungi, micro-organisms) living together in different locations around the world.
- Humanity relies on these ecosystems for our very survival - they produce the fresh water, clean air, food, wood and other natural products that are indispensable to our lives.
- The earth's ecosystems are currently being vastly disrupted by human activity causing species to go extinct, and the health of ecosystems to diminish
- We need to change how humanity acts in the world so that we can preserve and repair ecosystems and stop extinctions, if not for the sake of other forms of life, then for ourselves.
Ecosystems are groups of species that all live together in a certain area. There can be many thousands of species, and they constantly interact and rely on each other to maintain the integrity of the whole. Plants form the basis of the food chain, taking energy from the sun and turning it into living tissue. Different plants fill different niches, some as tall trees, as grass, as climbing vines, some dropping their leaves for the winter and others keeping them all year. There are animals eating plants, other animals eating those animals, fungi decomposing everything that dies to recycle nutrients and begin the growth anew. Micro-organisms are found by the trillions in every nook and cranny.
While some (myself included) could wax poetic about the grandeur of wild spaces, of the beauty of old growth forests, or the thought of herds of bison roaming the prairies, providing beauty is far from the only thing that ecosystems do for us. Critical to the very survival of humanity are all of the things that ecosystems do for us, often called ecosystem services. Intact ecosystems provide us with soil, food, water, medicine, wood and other plant fiber, they maintain climate and rainfall patterns, and more. To provide all of these functions that we hold so dear, ecosystems need to be maintained in a healthy state. There are innumerable instances where people's damaging of lands and waters led directly to massive problems in human society. Floods, soil erosion, desertification, wildfires, polluted water, can all be caused by poor management practices, and can threaten the very foundations of societies. In today's world, climate change is linked tightly with ecosystem damage, as poor forest management and poor agricultural practices are some of the main drivers of a warming planet. In terms of species extinction, it is estimated that current human practices are causing the rate of species extinction to be a thousand times higher than what it was before the modern age, and we are currently be losing thousands of species every single year.
People need to act now to preserve ecosystems and species. We know that ecosystems are resilient, but it is unclear how much abuse they can take before problems may spiral out of control. There is something called the precautionary principle that tells us that we shouldn't take dangerous actions when we are unsure of how risky they are. The cost of doing nothing could be absolutely immense, whereas if we act now to change 'business as usual', we know that this is likely to lead to great outcomes for both people and the planet. There will be some costs associated with making these changes, but the long-term benefits to saving ecosystems and species far outweigh the short-term benefits of massive scale clear-cut logging or agricultural practices that destroy the fertility of the soil.
Sunday, 19 November 2017
Global climate change - the scope of the problem
This post is a part of the Manitou Initiative series of articles.
The super short version of the problem of global climate change is as follows:
First, there is a natural carbon cycle on the planet. Carbon is a basic physical element, found in great quantities both on the surface and in the center of the earth, though it makes up only a small proportion of all of the matter of the earth. Most of this carbon is under the surface, bound up in rocks, in the earth's core, or in fossilized plants that have been buried by the action of water, wind, and time. Then there is the carbon found on or near the surface that cycles back and forth between the air, the water, the rocks and soil, and living things. All life that we know is built out of carbon molecules, and all living things spend much of their time and energy bringing carbon into their bodies. Plants draw it from the air while animals eat other living things made out of carbon. The earth's cycle of carbon is always in flux, plants are growing and dying, animal populations rise and fall, rocks and water absorb and release it. The main point to make about the cycle is that the amount of carbon actively moving around the surface, the waters, and the atmosphere, has stayed in equilibrium for millions of years. The equilibrium amount of carbon in the atmosphere, mostly as carbon dioxide, has stayed about 300 parts per million (a quite small proportion of the air) for at least hundreds of thousands of years up until about one hundred years ago.
The problem that we face today is that people have thrown off this balance, as human activities have drastically increased the amount of carbon going into the atmosphere, much more than the natural systems and cycles can absorb. The most notorious source has been the fossil fuels of coal, oil, and natural gas. These substances once were living organisms, and were trapped underground and transformed into concentrated carbon based energy. When we burn them, we release carbon back into the atmosphere that has been out of circulation for millions of years. Another huge contributor to carbon in the atmosphere is poor land use. For example, forests are cut down, poor agricultural practices destroy soil, cows produce lots of methane (another carbon based greenhouse gas), all of which lead to the carbon stored in these places being released to the atmosphere. Industrial processes can also add carbon to the atmosphere. One such process is the production of cement. Cement is made by heating rock (limestone) that is high in carbon, leading both to a useful product as well putting more carbon dioxide into the atmosphere. The sum of these activities cause the amount of carbon in the atmosphere to rise. Today in the fall of 2017, the amount of carbon dioxide in the atmosphere has risen by a third, to 405 ppm. Current human activities are causing a continued 1 ppm increase each and every year.
Now, the biggest reason that all of this extra carbon in the atmosphere is a problem is due to the greenhouse effect. The basic analogy of the greenhouse effect is that the glass walls of a greenhouse trap some of the energy from the sun, allowing the inside of a greenhouse to be warmer than the air outside. It turns out that the earth's atmosphere does the same thing. An enormous amount of energy from the sun hits the earth, with some staying and some bouncing back into space. Carbon dioxide and other greenhouse gases in the atmosphere do the same thing as the glass in the greenhouse walls, they trap heat inside. The more greenhouse gases in the atmosphere, the warmer the earth stays. This has mostly been a great thing for life on earth, as the greenhouse effect is the reason that we have such moderate temperatures today that life on earth is so well adapted to. As mentioned in the last paragraph, carbon dioxide in the atmosphere has risen by a third, and this has trapped more heat through the greenhouse effect. So far, this rise in atmospheric carbon has increased the earth's temperature by nearly one degree Celsius. If current trends of humanity's resource and land use continue, this could reach 5 or 6 degrees Celsius (10 degrees Fahrenheit) by the year 2100. Humanity now stands at a point where we are cooking ourselves out of house and home. It is impossible to predict all the effects of this warming, but we do know that it would be catastrophic. Sea levels would rise, weather extremes of flood, drought and wildfire would increase, some ecosystems would collapse and many species would go extinct, and there would be millions of climate refugees fleeing these effects.
Put all together this makes for a very simple goal in fighting climate change, though it will be difficult and complex to achieve: humanity needs to stop putting excess greenhouse gases into the atmosphere if we want to save ourselves and our planet.
The super short version of the problem of global climate change is as follows:
- Carbon dioxide and other greenhouse gases in the atmosphere trap heat from the sun
- People are vastly increasing the amount of greenhouse gases in the atmosphere, which means we trap more heat, which means the temperature of the planet is rising
- A fast rising temperature causes massive problems for humanity and all other life on earth
- We need to stop putting extra greenhouse gases into the atmosphere if we want a livable and sustainable world
First, there is a natural carbon cycle on the planet. Carbon is a basic physical element, found in great quantities both on the surface and in the center of the earth, though it makes up only a small proportion of all of the matter of the earth. Most of this carbon is under the surface, bound up in rocks, in the earth's core, or in fossilized plants that have been buried by the action of water, wind, and time. Then there is the carbon found on or near the surface that cycles back and forth between the air, the water, the rocks and soil, and living things. All life that we know is built out of carbon molecules, and all living things spend much of their time and energy bringing carbon into their bodies. Plants draw it from the air while animals eat other living things made out of carbon. The earth's cycle of carbon is always in flux, plants are growing and dying, animal populations rise and fall, rocks and water absorb and release it. The main point to make about the cycle is that the amount of carbon actively moving around the surface, the waters, and the atmosphere, has stayed in equilibrium for millions of years. The equilibrium amount of carbon in the atmosphere, mostly as carbon dioxide, has stayed about 300 parts per million (a quite small proportion of the air) for at least hundreds of thousands of years up until about one hundred years ago.
The problem that we face today is that people have thrown off this balance, as human activities have drastically increased the amount of carbon going into the atmosphere, much more than the natural systems and cycles can absorb. The most notorious source has been the fossil fuels of coal, oil, and natural gas. These substances once were living organisms, and were trapped underground and transformed into concentrated carbon based energy. When we burn them, we release carbon back into the atmosphere that has been out of circulation for millions of years. Another huge contributor to carbon in the atmosphere is poor land use. For example, forests are cut down, poor agricultural practices destroy soil, cows produce lots of methane (another carbon based greenhouse gas), all of which lead to the carbon stored in these places being released to the atmosphere. Industrial processes can also add carbon to the atmosphere. One such process is the production of cement. Cement is made by heating rock (limestone) that is high in carbon, leading both to a useful product as well putting more carbon dioxide into the atmosphere. The sum of these activities cause the amount of carbon in the atmosphere to rise. Today in the fall of 2017, the amount of carbon dioxide in the atmosphere has risen by a third, to 405 ppm. Current human activities are causing a continued 1 ppm increase each and every year.
Now, the biggest reason that all of this extra carbon in the atmosphere is a problem is due to the greenhouse effect. The basic analogy of the greenhouse effect is that the glass walls of a greenhouse trap some of the energy from the sun, allowing the inside of a greenhouse to be warmer than the air outside. It turns out that the earth's atmosphere does the same thing. An enormous amount of energy from the sun hits the earth, with some staying and some bouncing back into space. Carbon dioxide and other greenhouse gases in the atmosphere do the same thing as the glass in the greenhouse walls, they trap heat inside. The more greenhouse gases in the atmosphere, the warmer the earth stays. This has mostly been a great thing for life on earth, as the greenhouse effect is the reason that we have such moderate temperatures today that life on earth is so well adapted to. As mentioned in the last paragraph, carbon dioxide in the atmosphere has risen by a third, and this has trapped more heat through the greenhouse effect. So far, this rise in atmospheric carbon has increased the earth's temperature by nearly one degree Celsius. If current trends of humanity's resource and land use continue, this could reach 5 or 6 degrees Celsius (10 degrees Fahrenheit) by the year 2100. Humanity now stands at a point where we are cooking ourselves out of house and home. It is impossible to predict all the effects of this warming, but we do know that it would be catastrophic. Sea levels would rise, weather extremes of flood, drought and wildfire would increase, some ecosystems would collapse and many species would go extinct, and there would be millions of climate refugees fleeing these effects.
Put all together this makes for a very simple goal in fighting climate change, though it will be difficult and complex to achieve: humanity needs to stop putting excess greenhouse gases into the atmosphere if we want to save ourselves and our planet.
Friday, 31 March 2017
Energy from the land - Photovoltaic solar panels
This post is a part of the series An Acre of Sunshine.
While all of the posts that I've written so far have focused on the energy that we can harvest through the plants and animals that we grow on the land, these are not the only way to make the sun's energy useful to us. There have long been ways of harvesting some of the sun's energy as heat, and it has become now become feasible, and even economical, to convert the sun's energy directly into electricity, and humanity uses a lot of electricity to make our technologically intense world go round. Photovoltaic (PV) panels are not the only way of generating electricity from the sun, but have become a very practical way to provide power at both a small and large scale. All of the most complicated work of assembly is done in a factory, and once wired into place, the panels need little to no maintenance for their lifetime of several decades.
I won't bother going into the details of the history of photovoltaics, or their chemistry for that matter, but I do think that it is important to compare and contrast PV with photosynthesis at a higher level. Plants evolved photosynthesis over a very long timescale, figuring out through trial and error how to capture some small fraction of the energy pouring down in sunlight and passing it along through a quite long series of chemical reactions until it reaches a form that can be used to grow and maintain a plant. As was discussed here, this process has an efficiency of about 2%, and that is only when conditions are just right. When it comes to photovoltaics, scientists and engineers were inspired by photosynthesis, but free to explore the possibilities afforded by any materials available, not just those organic molecules that make up plants. Metals, glass, inorganic compounds of all kind were fair game as they tried to figure out how to harness sunlight. It has also turned out to be the case that it is easier to generate electric current than it is to build up sugars, fats, or other chemical energy storage. Put together this means that the PV panels widely available today can turn about 15% of the sun's energy into electricity, and can work on any day of the year; they don't take the winter off the way that our local plants do. These panels can create a steady stream of electrical energy any time they are exposed to sunny skies, and even cloudy skies to a lesser extent.
Estimate #1. From first principles.
We only really need one estimate here, as the numbers are really quite straightforward. First is the question of how efficiently PV panels can convert solar energy into electricity. At the moment, the typical commercially available panels are roughly 15% efficient, though more expensive ones approach 20%. Some laboratories are pushing to 30% or beyond with new architectures and chemistries. For the sake of argument, we shall stay with that 15% number.
The second aspect to consider is how much of the ground is actually being covered with the panels. Native ecosystems often have leaves spread over every inch of ground, whether it be a forest canopy or a field of waving grasses. While one could simply spread out solar panels flat on the ground covering every inch, this isn't an efficient use of resources. Instead panels are tilted so that they are as close as possible to perpendicular with rays of sunlight streaming down. And because one doesn't want the panels to shade each other out, it is necessary to space them out on the land. In larger installations, this spacing also makes for easy access between the rows of panels for doing any needed maintenance. Solar farms often actually cover only about 25% of the surface area where they are found. With these two figures we can do the same calculations for annual harvest that we have done for other land uses:
5,112,641 kWh/acre/year of sunlight * 15% efficiency * 25% packing factor = 191724 kWh/acre/year
For those of you keeping score, this is tremendously more energy than anything that can be harvested from plants. This is 10-15 time the energy that one could get from our most productive plant of corn, and 50 times the energy that can be harvested from cutting timber. The two arrays seen at the top of the page at my house are capable of producing about 10,000 kWh/year, roughly the same as what 3 acres of forest can do. Electricity can't be easily turned into food or furniture, but for anything that electricity can do, this makes photovoltaics a very easy winner.
Previous Page: Food from the land - Annual crops
Next Page:Coming soon
While all of the posts that I've written so far have focused on the energy that we can harvest through the plants and animals that we grow on the land, these are not the only way to make the sun's energy useful to us. There have long been ways of harvesting some of the sun's energy as heat, and it has become now become feasible, and even economical, to convert the sun's energy directly into electricity, and humanity uses a lot of electricity to make our technologically intense world go round. Photovoltaic (PV) panels are not the only way of generating electricity from the sun, but have become a very practical way to provide power at both a small and large scale. All of the most complicated work of assembly is done in a factory, and once wired into place, the panels need little to no maintenance for their lifetime of several decades.
Solar panel arrays at the author's home
I won't bother going into the details of the history of photovoltaics, or their chemistry for that matter, but I do think that it is important to compare and contrast PV with photosynthesis at a higher level. Plants evolved photosynthesis over a very long timescale, figuring out through trial and error how to capture some small fraction of the energy pouring down in sunlight and passing it along through a quite long series of chemical reactions until it reaches a form that can be used to grow and maintain a plant. As was discussed here, this process has an efficiency of about 2%, and that is only when conditions are just right. When it comes to photovoltaics, scientists and engineers were inspired by photosynthesis, but free to explore the possibilities afforded by any materials available, not just those organic molecules that make up plants. Metals, glass, inorganic compounds of all kind were fair game as they tried to figure out how to harness sunlight. It has also turned out to be the case that it is easier to generate electric current than it is to build up sugars, fats, or other chemical energy storage. Put together this means that the PV panels widely available today can turn about 15% of the sun's energy into electricity, and can work on any day of the year; they don't take the winter off the way that our local plants do. These panels can create a steady stream of electrical energy any time they are exposed to sunny skies, and even cloudy skies to a lesser extent.
Estimate #1. From first principles.
We only really need one estimate here, as the numbers are really quite straightforward. First is the question of how efficiently PV panels can convert solar energy into electricity. At the moment, the typical commercially available panels are roughly 15% efficient, though more expensive ones approach 20%. Some laboratories are pushing to 30% or beyond with new architectures and chemistries. For the sake of argument, we shall stay with that 15% number.
Les Mées Solar Farm, Photo by Jean-Paul Pelissier/Reuters
The second aspect to consider is how much of the ground is actually being covered with the panels. Native ecosystems often have leaves spread over every inch of ground, whether it be a forest canopy or a field of waving grasses. While one could simply spread out solar panels flat on the ground covering every inch, this isn't an efficient use of resources. Instead panels are tilted so that they are as close as possible to perpendicular with rays of sunlight streaming down. And because one doesn't want the panels to shade each other out, it is necessary to space them out on the land. In larger installations, this spacing also makes for easy access between the rows of panels for doing any needed maintenance. Solar farms often actually cover only about 25% of the surface area where they are found. With these two figures we can do the same calculations for annual harvest that we have done for other land uses:
5,112,641 kWh/acre/year of sunlight * 15% efficiency * 25% packing factor = 191724 kWh/acre/year
For those of you keeping score, this is tremendously more energy than anything that can be harvested from plants. This is 10-15 time the energy that one could get from our most productive plant of corn, and 50 times the energy that can be harvested from cutting timber. The two arrays seen at the top of the page at my house are capable of producing about 10,000 kWh/year, roughly the same as what 3 acres of forest can do. Electricity can't be easily turned into food or furniture, but for anything that electricity can do, this makes photovoltaics a very easy winner.
Previous Page: Food from the land - Annual crops
Next Page:Coming soon
Food from the land - Annual crops
This post is a part of the series An Acre of Sunshine.
Going along with the main theme of this series, the following post gives some quick estimates about the energy yields that different crops can produce, starting with a more in-depth discussion of corn.
Estimate #1 for Corn - From first principles
Cereal crops are plants that are grown for their starchy seeds, including corn, wheat, barley, oats, and others. When it comes right down to it, these are some of the most important plants for feeding the world. Corn makes a good example, and is one of the most productive crops per acre, period. The following estimates are for field corn, which is quite different than the sweet corn that you have eaten at dinner. It is much richer in oils, yields much more energy per acre, and is primarily used for animal feed, ethanol fuel production, as well as thousands of other uses in processed foods and chemical products.
In looking at photosynthesis, we found that our farm has about 36000 kWh/acre/year of basic photosynthetic energy production. Out of that amount, a plant needs to grow, metabolize, fight off predators, as well as to create that portion of the plant that is useful to us. In this case, what we actually want is the kernels of corn on each ear. Research on this subject shows that approximately 50% of a mature corn plant's energy is found in the kernels on the ears of corn, while the other 50% is in the stalk, leaves, and root system. This is actually a tremendous proportion of the energy of a corn plant that is found in the kernels. It is pretty incredible that these plants are able to funnel fully half of their energy into their seeds and that such a surprisingly small proportion is needed to grow the rest of the plant.
The other thing to account for is what proportion of the energy that a plant captures is put towards growth, and what proportion to maintain the health of the plant as it lives day to day, known as respiration. One source estimates respiration on a global scale at 20%, so as I didn't quickly find an actual figure for corn, we shall use that number. With this calculation, we get:
35788 kWh/acre/year * .5 (proportion of stored energy in seeds) * .8 (losses for respiration) = 14,315 kWh/acre/year of harvested corn kernels.
Estimate #2 for Corn - Real world yields
As I was not able to easily find Quebec data, I will instead use Ontario estimates of corn production to make an estimate. These recent data state that corn yields are typically around 150 to 170 bushels per acre per year of field corn (a bushel of corn is 56 pounds). As our farmland is of a much lower quality than the average farmed acre in Ontario, it could produce perhaps only about 2/3 of the average production. This means that one of our acres could produce:
150 bushels/acre/year * 2/3 (reduction for poor quality land) * 56 pounds/bushel * 1550 Calories/pound * (1 kWh/860 Calories) = 10093 kWh/acre/year
Other crops
In my last post, I showed a graph that included Calorie yields for many staple crops, and those are easy to convert to our usual unit of kWh. I also found plenty of sources (e.g., here and here) that listed the productivity of crops of all kinds, which often end up being much lower total energy because of how few calories many vegetables have (having high water content, high fiber, low fat). I've put a few of those estimates in the following table.
Previous Page: Food from the land - Growing domesticated crops
Next Page: Energy from the land - Photovoltaic solar panels
Going along with the main theme of this series, the following post gives some quick estimates about the energy yields that different crops can produce, starting with a more in-depth discussion of corn.
Estimate #1 for Corn - From first principles
Cereal crops are plants that are grown for their starchy seeds, including corn, wheat, barley, oats, and others. When it comes right down to it, these are some of the most important plants for feeding the world. Corn makes a good example, and is one of the most productive crops per acre, period. The following estimates are for field corn, which is quite different than the sweet corn that you have eaten at dinner. It is much richer in oils, yields much more energy per acre, and is primarily used for animal feed, ethanol fuel production, as well as thousands of other uses in processed foods and chemical products.
In looking at photosynthesis, we found that our farm has about 36000 kWh/acre/year of basic photosynthetic energy production. Out of that amount, a plant needs to grow, metabolize, fight off predators, as well as to create that portion of the plant that is useful to us. In this case, what we actually want is the kernels of corn on each ear. Research on this subject shows that approximately 50% of a mature corn plant's energy is found in the kernels on the ears of corn, while the other 50% is in the stalk, leaves, and root system. This is actually a tremendous proportion of the energy of a corn plant that is found in the kernels. It is pretty incredible that these plants are able to funnel fully half of their energy into their seeds and that such a surprisingly small proportion is needed to grow the rest of the plant.
The other thing to account for is what proportion of the energy that a plant captures is put towards growth, and what proportion to maintain the health of the plant as it lives day to day, known as respiration. One source estimates respiration on a global scale at 20%, so as I didn't quickly find an actual figure for corn, we shall use that number. With this calculation, we get:
35788 kWh/acre/year * .5 (proportion of stored energy in seeds) * .8 (losses for respiration) = 14,315 kWh/acre/year of harvested corn kernels.
Estimate #2 for Corn - Real world yields
As I was not able to easily find Quebec data, I will instead use Ontario estimates of corn production to make an estimate. These recent data state that corn yields are typically around 150 to 170 bushels per acre per year of field corn (a bushel of corn is 56 pounds). As our farmland is of a much lower quality than the average farmed acre in Ontario, it could produce perhaps only about 2/3 of the average production. This means that one of our acres could produce:
150 bushels/acre/year * 2/3 (reduction for poor quality land) * 56 pounds/bushel * 1550 Calories/pound * (1 kWh/860 Calories) = 10093 kWh/acre/year
Other crops
In my last post, I showed a graph that included Calorie yields for many staple crops, and those are easy to convert to our usual unit of kWh. I also found plenty of sources (e.g., here and here) that listed the productivity of crops of all kinds, which often end up being much lower total energy because of how few calories many vegetables have (having high water content, high fiber, low fat). I've put a few of those estimates in the following table.
Previous Page: Food from the land - Growing domesticated crops
Next Page: Energy from the land - Photovoltaic solar panels
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