Each Country Has a Unique GHG Emission Trajectory and Mitigation Challenge

When one examines GHG emissions on a coimtry by country basis, fundamental differences in emission characteristics and mitigation challenges are observed. Table 1 (generated based on databases from Global Carbon Atlas (2018)) summarizes CO, emission data for the 14 largest emitters in 2017. They are positioned in the order of the magnitude of their emissions. China, the EU and the U.S. are by far the largest emitters. The developed countries are identified by the normal font, while those in various stages of economic transition are in the bold font. Let us briefly discuss the situation in key developed countries and then in developing countries. At this point it should be noted that the IPCC (2013) has concluded that, in order to have a chance of limiting wanning to no greater than 2 °C, global per capita emissions should be between 1.1 and 2.2 t/person in 2050 and zero in 2100.

China is by far the largest emitter, passing the U.S. in 2006. It is considered somewhere between a developing and a developed country. Their 17-year emission growth rate at 6.6% is unmatched by any other country. They have rapidly transformed from a low-end developing country to a country with unprecedented economic growth via rapid urbanization, industrialization (supported by an unprecedented power generation expansion, primarily based on coal), and major growth of their on-road transportation fleet. Population growth at 0.6% has been only a minor factor in influencing their rapid emission growth. Their per capita emission has grown dr amatically to 7 t/p and still growing.

Country

2017 Emissions GT CO,

2017 per Capita Emissions tonnes/person

2017 Population millions

2000 to 2017 Annual Emission Growth Rate

2000 to 2017 Annual Population Growth Rate

China

9863

7.0

1409

6.6%

0.6%

USA

5184

16.0

324

-0.9%

0.8%

EU

3544

7.0

507

-1.0%

0.2%

India

2446

1.8

1359

5.2%

1.5%

Russia

1716

12.0

143

0.8%

-0.1%

Japan

1207

9.5

127

-0.3%

0.0%

Iran

672

8.3

81

3.6%

1.2%

Saudi Arabia

627

190

33

4.5%

2.7%

S. Korea

616

12.0

51

1.9%

0.5%

Canada

592

16 0

37

0.2%

1.0%

Brazil

481

2.3

209

2.3%

1.0%

Indonesia

475

1.8

264

3.5%

1.3%

S Afnca

456

8.0

57

1.1%

1.3%

Australia

408

17 0

24

09%

1.4%

Rest of World

7866

2.6

2995

3.7%

2.2%

Total

36153

4.7

7620

2.3%

1.3%

IPCC: Pei' Capita target for 2 °C maximum wanning = 1 1 to 2.2 m 2050 and near Zero in 2100.

The U.S. and the EU are both highly developed with similar standards of living, yet the EU’s per capita emissions are less than half those of the U.S. The EU has been the most conscientious regarding minimizing GHG emissions, has had a culture of treating energy conservation seriously, and uses less electricity per capita, in part because of very high electric rates. They have also has been leaders in utilizing wind and solar power. As a more population dense area with less dependence on large low- efficiency cars and trucks, their transportation emissions are much lower as well. Finally, the very low population growth has also been a factor. However, for both the EU and especially the US, reducing per capita emissions to the 1.1 to 2.2 level by 2050 will be a monumental challenge.

The developing world is in a fundamentally different situation. Per Table 1, countries in this categoiy would be include India, Iran, Brazil. Indonesia and many African, South American and Asian countries in the “Rest of the world” designation. It is estimated that over 4 billion people fall in this categoiy. They generally har e similar characteristics: Low standards of living, modest per capita incomes, high birth rates and relatively low per capita emissions. The challenge for developing countries is to improve then- economies while at the same time lowering or at least not raising then per capita emissions. India is a particularly important case since its population is close to that of China, with a fast-growing economy and a major increase in emissions (and per capita emissions) in recent years. This is not the direction this sector of the world’s economy should be heading if we are serious about avoiding unacceptable climate change.

Greenhouse Gas Emissions are Associated with All Energy, Industrial and Agricultural/Land Use Sectors

In order to appreciate the scope of the mitigation challenge, it is important to understand the relationships between: The energy', industrial and agricultural/land use sectors, the related activities that are needed for the desired societal end uses (“needs”) and the resulting GHG emissions. Figure 8 (WRI, 2007) quantifies these relationships for the world as of 2005, the last year such a chart was published. An example of these relationships follows: If the end use/activity is heating, cooling and lighting residential buildings, the relevant sectors are Electricity and Other Fuel Combustion. This is the case since some residences are heated with electricity (heat pumps or resistance heating) and others via direct combustion of a fuel, such as natural gas. So, both electricity and fuel combustion sectors contribute to CO, emissions associated with residential buildings, as indicated in Figure 8.

As can be seen, key end uses that drive energy-related emissions include road travel, residential and commercial building cooling, heating and lighting and the production of chemicals, cement, and iron & steel needed for production of goods. The net result are huge emissions of CO„ most of which are associated with the combustion of coal, oil and natural gas. Also, the agricultural sector is responsible for the majority of emitted methane, the second most important greenhouse gas. Land use change was another important contributor to raising CO, concentrations, however less active deforestation in recent years has decreased the importance of this sector. Note that in 2005, 77% of the anthropogenic wanning was associated with CO„ with methane and N,0 contributing 15% and 7%, respectively Also note, that the term CO, equivalent [CO,(e)] emissions, is the amount of CO, which would har e the equivalent global wanning impact when accounting for CO, plus the other GHG gases. For 2005 that number globally was 44 Gt(e).

Major Emission Mitigation from All Sectors and GHGs is Required Immediately in Order to Have a Chance of Meeting International Targets

In order to have a chance of limiting warming to between 1.5 and 2.0 °C per the international community’s stated target, it will be necessary to drastically reduce emissions as soon as possible. Figures 9 and 10 have been generated in order to help quantify this monumental challenge. The previously mentioned MAGICC model was used. Wanning projected should be considered as “best guess” values, considering that there are uncertainties in such values, especially for long term projections. Both figures assess the

Global Greenhouse Gas emissions in 2005 by sector, end use and gas

Figure 8. Global Greenhouse Gas emissions in 2005 by sector, end use and gas.

wanning implications of six emission scenarios; Figure 9 shows the assumed emission scenarios in Gt CO, and Figure 10 shows the projected wanning all the way to 2100, associated with these emission scenarios:

  • 1) A business as usual case that assumes continued reliance on fossil fuels with no serious mitigation reductions for methane and nitrous oxide, the two other key GHGs.
  • 2) A scenario consistent with the 2015 Paris Agreement where most countries “promised” significant but relatively modest emission reductions.
  • 3) A serious CO, global emission reduction program with near term emission stabilization and 3% annual emission reductions, stalling in 2035 and continuing for 65 years.
  • 4) Scenario 3 above, with the addition of a complimentary CH4 and N,0 emission reduction program, starting in 2035 as well.
  • 5) Scenario 4 above, but with the addition of a major Direct Atmospheric Capture (DAC) program to remove CO, from the atmosphere, starting in 2030 and continuing for 70 years.
  • 6) Scenario 5 above, but with CO,, methane and N,0 mitigation starting ten years earlier, in 2025, and maintained for 75 years.

As can be seen, with 3% annual CO, mitigation starting in 2035, it will be difficult to limit wanning to below 2 °C. The addition of CH4 and N,0 mitigation significantly reduces the wanning, but limiting warming to 2 °C still appears unlikely. When one adds a major Direct Air Capture (DAC) component to the mitigation strategy it appears that limiting warming to 2 °C may be achievable. Finally, if we start CO,, CH4 and N,0 emission reductions ten years earlier, in 2025, and again supplement with a major DAC complimentary program, further wanning reduction is achieved, raising the probability that warming would be limited to 2 °C. It is worth noting that none of these options appear to be able to limit warming to 1.5 °C, a likely unattainable target. DAC technology involves the construction of massive chemical plants designed to remove CO, directly from the atmosphere.

Six GHG emission scenarios, Gt CO, per year

Figure 9. Six GHG emission scenarios, Gt CO, per year.

Projected warming associated with six GHG emission scenarios, Degree Celsius

Figure 10. Projected warming associated with six GHG emission scenarios, Degree Celsius.

It should be noted that DAC technology is at a very early stage of development and implementation costs are likely to be very high per ton of carbon captured. Keith (2018) has analyzed a chemical sorbent process, aqueous sorbent KOH coupled to a calcium caustic sorbent recovery loop, and estimated capture costs at $94 to $232 per ton. Options 5 and 6 described above, assume DAC capture would start in 2030 with progressively greater annual removal quantities for a total of 37 Gt for the 70-year mitigation period.

Given this quantity, the estimated cost of such DAC capture would be between S1.3 to S2.5 trillion per year or S72 and SI78 trillion over the 70-year period! This study did not include the required costs for permanent storage of the CO,, probably in deep underground saline aquifers, which will likely add trillions of USS to the cost of such an enterprise.

 
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