I'm a professor at U Michigan and lead a course on climate change problem solving. These articles often come from and contribute to the course.
By: Dr. Ricky Rood , 4:51 AM GMT on April 09, 2014
Energy, Food, Population and Climate
I was reading this article, Green Energy Draws Investment Worldwide, which reports on the United Nations' Global Trends in Renewable Energy Investments 2014. The article documents that global investments in renewable energy dropped in 2013, but also notes that China now exceeds Europe in renewable energy investments. Part of the reason for reduced investment in renewable energy was due to the declining price of solar energy. Another reason is unstable energy policy. In the U.S., for instance, the investment in wind energy jumps up and down based on incentives such as tax credits. The amount of energy produced by renewables continues to increase from year to year. If we obtained this energy from fossil fuels, there would be approximately 20% more carbon dioxide emissions.
Even with accounting that carbon dioxide emissions are only 80% of what they might be, the total global emissions of carbon dioxide continue to increase every year. Here is a figure put together from reports from the International Energy Agency.
Figure 1: World Primary Energy Supply in 1973 and 2003. From International Energy Agency.
In 1973 oil provided 45.0 % of the world’s energy and in 2003 the number is 34.4%. Natural gas provided 16.2% in 1973 and 21.2% in 2003. Coal was 24.8% in 1973 and 24.4% in 2003. If I add correctly in 1973 fossil fuels provided 86% of the world’s energy and in 2003 fossil fuels provided 80% of our energy. The big difference between 1973 and 2003 was the increase in nuclear.
The emissions continue to increase because the total amount of energy generated increased. Mtoe is Megatons oil equivalent, and that number went from about 6,000 to 10600 in 30 years. In that 30-year period there was about a 75% increase in total energy production.
Figure 2 shows in the top part of the figure the same type of information as in the above figure, but for 2011. Total energy production in 2011 was about 13,113 Megaton oil equivalent. In 2011, the increase in energy production is approximately 120% compared to 1973. Compared to 2003, the 2011 energy production is about 25% higher.
Figure 2: World Primary Energy Supply in 2011, top. From International Energy Agency. Total energy production in 2011 was about 13,113 Megaton oil equivalent. The bottom part of the figure is the percentage of carbon dioxide emissions from each energy type.
When we look at the percentage of energy production, the energy coming from non-fossil fuel sources is 18%. Percentage wise, the amount that might be accounted to renewables has actually decreased. Therefore, we do have less carbon dioxide emissions than might be the case, but our energy use increases and our reliance on fossil fuels remains in many ways the same. The amount of energy produced by non-fossil fuels today would have been over 40% of the world’s energy use in 1973.
In terms of share of energy production, coal has increased at the expense of both oil and non-fossil fuels. If you look at the bottom part of the figure, the high amount of carbon dioxide emissions from coal shows that coal is especially bad for the climate.
In the past decade, globally, coal has grown more than either renewables or natural gas. This has fueled, especially, the economies of India and China, leading to a significant rise in standard of living. This shows up as large changes in, for example, hunger statistics. The tie between economic success, energy use and carbon dioxide becomes more clear. Despite amazing growth in the use of renewables, which has actually decreased carbon dioxide emissions in Europe, the total growth in energy production overwhelms this decrease. This makes the current continued increase in carbon dioxide emissions more staggering – it comes in the presence of real reductions in emissions from renewables.
The increase in energy production improves economies. Bringing economic development to a larger percentage of the world’s population, while the population continues to grow, assures decades more of very high emissions. If we then make the reach that economic growth and standard of living are accompanied by consumption of more meat, which has always been the case, we see an amplifying impact on emissions coming from agriculture.
We are therefore even in the best of cases committed to further increases in carbon dioxide emissions, as well as emissions of other greenhouse gases. The ultimate way to limit warming is to reduce emissions, which requires energy sources and food supplies that do not emit greenhouse gases. At this point we are not even offsetting the increase of carbon dioxide emissions by our adoption of renewables. It is interesting to note that China, now the world’s largest emitter, is also the world’s largest investor in renewable energy. Also noteworthy, is that China has driven down the price of solar energy. This places China in not only a potential technological advantage, but is also building policy advantage, as China is on a path that might displace coal’s role in energy production.
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