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China's impact on Global Climate Change

This story describes the effect of China's emission reduction or lack thereof to global climate change

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  1. China is currently the country with the most greenhouse gas emission in the world by a huge margin. Its carbon dioxide emissions double that of the runner-up country, the United States of America, and contributes to 29 percent of the global emissions. The figure below shows 2013 values of the top 7 countries with the most carbon dioxide emissions. (Photo source: Netherlands Environmental Assessment Agency)
  2. China's future emissions range anywhere from 7 to 20 Gigatons of carbon dioxide by 2050. The figure below shows the projected carbon emission paths for China in three scenarios: "no policy", "continued effort", and "accelerated effort". The "no policy" scenario projects emissions if China does not regulate carbon emission. The "continued effort" scenario assumes that China remains on the path of reducing carbon intensity by around 40% every 15 years, dictated by the Copenhagen climate talk in 2009. The "accelerated effort" scenario assumes that China takes aggressive measures in reducing carbon by imposing carbon taxes and such. Below is a figure on the projected carbon paths (Photo source: Tsinghua-MIT Energy and Climate Project  http://globalchange.mit.edu/files/document/CECP_2014_Outlook.pdf )
  3. As you can see, with the "no policy" scenario, China's CO2 emissions will reach 16 Gigatons by 2030 and will not peak by even 2050. With the "continued effort" scenario, China's emissions will peak at around 12 Gigatons by 2030 - 2040 and will sustain at that level until 2050. With the "accelerated effort" scenario, China's emissions will peak at 10 Gigatons by 2025-2030 and will slowly decline from there.
  4. To understand the effect of China's policies on global climate change, we also need to look at the global carbon emission. According to IPCC 5, the annual global GHG emissions could vary by a great amount depending on the path that the world takes in its mitigation strategies. In the figure below, you can see the projected GHC emission paths for the world from 2010 to 2100, with varying mitigation scenarios. (Photo source: IPCC 5,  http://www.ipcc.ch/pdf/assessment-report/ar5/wg3/ipcc_wg3_ar5_full.pdf .) Please understand also that carbon dioxide emission is only a subset of GHG emission, accounting for around 60 to 70 percent of the total GHG emissions in the recent 30 years, also according to IPCC 5.
  5. Now I will take a look the effect of China's policy to global climate change by 2030. If we assume the median value of RCP 6.0, which is a moderate projection into the future, we can see that by 2030 the world will be emitting 60 Gigatons of GHG, and equivalently around 42 Gigatons of carbon dioxide. If we assume that the global RCP6.0 policy aligns with China's "continued efforts" scenario, China's policies and actual emissions will have a big global impact. To be specific, if China goes with "no policy", China's emission will be at 16 Gigatons by 2030, contributing to 35% of the world's 46 Gigatons. If China shows "continued effort", its 12 Gigatons by 2030 will contribute to 29% of the world's 42 Gigatons. If China shows "accelerated effort", its 10 Gigatons by 2030 will contribute to 25% of the world's 40 Gigatons. Whether the world will be emitting 46 or 40 Gigatons of carbon dioxide by 2030 completely rests within the hands of the east Asian Giant.
  6. The same can be said for the year 2050, when IPCC RCP6.0 predicts global emission to be 68 Gigatons of GHG, and around 48 Gigatons of CO2. Using the same principles as in the 2030 case, we will aligned RCP 6.0 with China's "continued effort" scenario, which will yield a 12 Gigaton emission by 2050. By 2050, If China enforces "no policy", its 21 Gigatons will contribute to 37% of the world's 57 Gigatons. If China employs "continued effort", its 12 Gigatons will contribute to 25% of the world's 48 Gigatons. If China goes aggressive with reduction, its 7 Gigatons will only contribute to 16 percent of the world's 43. Again, 57 Gigatons compared with 43 Gigatons is a huge difference.
  7. This decrease in CO2 and GHG emission has a direct effect on global climate change and on global temperature increase. Although it will take many years for the warming effect of the increased CO2 to kick in, we can still make a rough estimate by percentages. By 2030, 40 Gigatons is around 14 percent less than 46 Gigatons. By 2050, 43 Gigatons is around 28 percent less than 57 Gigatons. Say we can average these two percentages and say that by taking an aggressive approach to reducing carbon dioxide emissions, China can roughly reduce the global emissions and global temperature increase by 20%. That is a huge percentage!!!! If we look into 2100, China can single handedly decrease global temperature rise from 3 degrees C to 2.4 degrees C, or from 2 degrees C to 1.6 degrees C.
  8. China rarely makes any pledges on CO2 reduction and its mitigation goals to prevent global climate change. Only in the recent meeting between the leaders of China and the U.S. has China openly pledged its CO2 reduction goals for the first time. In this joint meeting between Chinese President Xi Jinping and U.S. President Barack Obama, Mr. Xi Jinping pledges that China will peak in carbon dioxide emissions by 2030. If Mr. Xi and China walks the talk, they will need to go towards the accelerated route of carbon reduction. They will need to pose heavier carbon taxes, shut down uncompliant powerplants, spend billions of dollars on carbon sequestration equipment and much more. These measures will definitely put a toll on China's economic growth and the living conditions of its people.
  9. So which route should China take? Should China sacrifice its own economic growth for the good of humanity or should it keep growing economically at its intended pace, while wreaking havoc to the global climate?
  10. Me personally? I think China may have to find its own sweet balance.
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