Saturday, June 20, 2015

Climate Change: CO2 Emissions Trends

Your faithful bloggist would like to take this opportunity to acquaint his readers with the information on trends about greenhouse gas (GHG) emissions.  This post is not about the underlying science as to whether human activities are having, or likely to have in the future, significant impact on global temperatures.  The emissions trend data is important because it bears on any potential policy responses to climate change.

Prompted by some projects at work before THC retired he began following annual data on global, regional and country-specific GHG emissions. Three primary sources of that data are the International Energy Agency, U.S. Energy Information Administration and the Netherlands Environmental Assessment Agency. While there are differences in methodology, the numbers are roughly similar and the trends identical. For purposes of the discussion below, except where otherwise noted, we'll use the Netherlands data (see also Footnote A, below).

1. Here are the actual GHG emissions from fuel combustion and cement production for major countries and regions since 1990. Units: 5.0 = 5,000 million tons CO2.

U.S. EU China Global
1990 5.0 4.3 2.5 22.7
1995 5.3 4.1 3.5 23.6
2000 5.9 4.1 3.6 25.4
2005 5.9 4.2 5.9 29.4
2010 5.5 3.9 8.7 33.0
2013 5.3 3.7 10.3 35.3


U.S emissions over this period have increased by about 6% but are 10% lower than they were in 2000.  The U.S. share of global emissions has shrunk from about 22% to 15%.

In 2013 US & EU emissions combined are lower than than they were in 1990 even as global emissions increased by more than 50%.  The US & EU accounted for 41% of global emissions in 1990 but less than 26% in 2013.

China’s emissions, which were only 60% of those of the U.S. in 2000, are today greater than those of the U.S. and EU combined with China accounting for about 60% of the growth in global emissions since 1990.  China now accounts for 29% of global emissions.

If THC had included the 2008 data you’d see that during the GW Bush years the U.S. and EU trended the same despite the latter being a signatory to Kyoto.

U.S GHG emissions plummeted in 2009 demonstrating that there is nothing like a massive recession to help reduce your emissions.  American reductions in the past few years are also driven by switches from coal to gas and the success of fracking.

The announced GHG reduction goal of the Obama administration is 28% by 2025 from a 2005 baseline which would require additional U.S. reductions of about 1,000 million metric tons. Under a business as usual case in which global emissions increased by 2% a year (substantially less than trend), the U.S. reductions would amount to less than 2.5% of what the projected global total would be in 2025 and by less than 1.5% if all GHG emissions are taken into account (see footnote A below).

According to climatologist Judith Curry, based upon the UN IPCC’s own modeling, if the U.S met the 28% goal it would reduce projected temperatures by only 0.03 degrees C in the year 2100. Further, if the U.S. reduced its emissions by 80% by 2050 temperatures would be lowered by 0.11 degrees C by 2100.

It is the world outside of the US and EU that will determine if total global emissions are reduced and, in particular, what China does.

2.  For all the recent talk of emissions reductions the single biggest factor in the largest GHG reductions in the past half-century is the work of the United States, and specifically of Ronald Reagan and allies like Margaret Thatcher, in bringing down the Soviet Union.

In 1990, GHG emissions from the Soviet Union, were 4,000 million tons or almost 18% of the global total. With the falling apart of the Soviet state the full wastage of its economic base was exposed – as we learned, in some instance, the value of the raw materials going into its products were actually higher than the value of the final products (not to mention that life expectancy was falling) ! Soviet production philosophies allowed for pollution of the environment on a scale not seen in the U.S. even at its worst. By 1998, GHG emissions from Russia and the former Soviet states were only 2,400 million tons, a reduction of 40% or 1,600 million tons (about a 6% global reduction), by far the biggest reduction ever (even in 2013 they were still only about 2,700 million tons).

It was the “hot air” produced by this collapse and the ability to sell it as carbon credits that enticed Russia to become a Kyoto signatory, putting that pact into legal effect. The related collapse of the East Germany’s industry and its subsequent absorption into a reunited Germany, reduced that country’s overall GHG emissions enough that it made compliance with the Kyoto goals relatively easy. It is no accident that Kyoto’s baseline was 1990 before the industrial collapse of the Soviet Union and Eastern Europe.

3. One of the other major changes in emissions profiles helping the EU meet its goals was Margaret Thatcher’s initiative to reduce coal mining in the U.K. and switch its economy to newly discovered natural gas found in the North Sea. U.K. emissions today are lower than they were in 1979, the year Ms Thatcher became Prime Minister. For that effort she was excoriated by the Left in Britain who lamented the closing of the coal pits. In the years since, the British film business has developed a cottage industry making movies glorifying the coal miners and denouncing Thatcherism (see, for instance, Billy Elliott) while at the same time demanding greenhouse gas reductions.

UPDATE (6/30/15):  This morning THC was watching BBC (yes, he actually does that occasionally) and one of their big stories was billed as China's dramatic announcement committing to reducing GHG emissions.  Many numbers were thrown around rather carelessly in the report so THC thought it would be a good opportunity to see how emissions data is used, misused and easily misunderstood.

The substance of the announcement was that China pledged to cap its emissions by 2030 and would make a 60-65% reduction in GHG intensity, essentially an efficiency measure, by that time (from a baseline in 2005), though THC noticed that the header running under the report characterized this as a 60-65% decrease in emissions, which it is not.

The piece featured an interview with BBC's Environmental Analyst, Roger Harribin, who stressed the significance of this commitment and also commented that until now the U.S. has resisted making commitments on the grounds that China was refusing to do so.

1.  The commitment is the same commitment made by China last November as reported at the time by The Washington Post.  It is not new news.

2.  At the same meeting last November, President Obama announced the U.S. reduction commitment, as discussed in the original post above.

3.  What does it mean for China to agree to cap its emissions by 2030?  From 2000 to 2013, China's GHG emissions grew at an average annual rate of a little more than 8% a year, though growth has slowed some in recent years.  If China were to reduce its average GHG growth rate to 2% annually its emissions would grow from 10,300 million tons to 14,500 million tons by 2030, the equivalent of adding more than the EU's 2013 emissions to the global total.

4.  But, you might protest, China emissions must surely go down in this period given they have pledged to reduce intensity by 60-65%?  Not necessarily.  Intensity is a relative measure which necessitates having a denominator.  In this case, China has said its denominator is GDP so the critical matter is the amount of GHGs emitted per unit of GDP.  So far in the 21st century, China's GDP has grown by 7-11% every year.

Let's assume that China's growth slows down through 2030 and is only 5% a year, well below the recent trend line.  If China's GHG emissions remain the same in 2030 as they were in 2013 the country would have reduced intensity by 60% from the 2005 baseline!  If China's growth remains at the low end of the recent trend (7%) emissions can increase and still hit the intensity target.

(Footnote A) A simplifying assumption has been used by THC as these numbers are only from fuel combustion and cement production. There are additional significant GHG emissions from other non-CO2 industrial gases, agriculture and forestry.  In some countries, such as Brazil and Indonesia, these sources are double those from fuel and cement.  In the U.S. and E.U. these sources add something like 20-25% to the figures about while in China they add perhaps 40%.

1 comment:

  1. Great data. What I'm really curious to see is these numbers on a per-GDP basis, since emissions seem so inextricably linked to economic activity.