By Bryan Van Gorp, Alexandria, MN
For hundreds of thousands of years, the CO2 level in the atmosphere was quite stable at around 280 ppm according to NOAA. With the industrial revolution, levels started to creep up and around 1960 levels really took off. Current levels are approximately 420 ppm. Thats a 50% increase in a human life span.
So what? Based on physics we know that the sun’s energy comes to earth in the complete spectrum of light, some of which is absorbed, heating the earth. Normally an equal amount of heat enters and leaves the earth. When that heat is radiated out, most of it is in the infrared spectrum, so more of it is absorbed by CO2 and other carbon containing molecules like methane. It is then reemitted, about half going out to space and half going back toward earth. The higher the carbon levels, the more is re-emitted back toward earth. This is the greenhouse effect.
What is the source of increasing levels of greenhouse gases? In the United States, 75% of emissions are from burning fossil fuels — petroleum 45%, natural gas 35% and coal 20%. 10% of the impact is from methane, released from landfills, fossil fuel production and agriculture. 7% of impact is from nitrous oxide, coming from fertilizers, industrial waste and burning fossil fuels. The rest is miscellaneous including refrigerants. Obviously, burning fossil fuel is the elephant in the room.
Where do emissions come from? Transportation accounts for 35%, industry 30%, residential 20% and commercial 15%. These numbers include the contribution from generating electricity, (about 1/3 of the total). Agriculture responsible for 10% of emissions, is included in these categories as well. When you research this, you may find slight differences in the numbers depending on source and time of reporting, but this is an accurate big picture view.
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When people say climate change is a hoax or that it is not caused by humans, they are really saying they do not understand the chemistry, physics and impact of adding 40+ billion tons of CO2 to the atmosphere every year. It is OK not to understand these things. We all have things we don’t understand. Just have the humility and common sense to listen to people who do.
So what about China and India? China does have twice the emissions the U.S. does. China has five time the population, therefore 40% as much emission per person. India has half the emissions of the U.S. with four times the population, so 12% as much emissions per person. U.S., Canada and Australia have the highest per-capita emissions, other than a few small oil producing countries in the Middle East. Historically the US with 5% of world population, has produced 25% of total greenhouse gases. We must own our responsibility for this problem.
Areas such as Brazil or Indonesia have large amounts of deforestation. Land use changes like these account for 10% of world emissions.
But this is something for our grandkids to worry about right? Actually no, it is here now and very urgent. Greenhouse gases stay in the atmosphere for decades, so things will continue to get worse for some time after we lower emissions. The Intergovernmental Panel on Climate Change report composed by leading climate scientists from 65 nations, including 234 authors are telling us definitively this is real and caused by humans. It is accelerating quickly, and we must act immediately and aggressively to avoid disaster. Yes, the climate has shifted before, but the pace of the current change is unprecedented and not comparable. Time to quit pretending that inaction is an option. Change is upon us, whether we acknowledge it or not.
