Author: Ip Tsz Yan Natalie, BBA (Law) IV; HKU

Date: 7/8/10

The principal sources of greenhouse gas pollution are electricity generation and transport. [1]

Kyoto Protocol

The United Nations Framework Convention on Climate Change and its Kyoto Protocol was extended to Hong Kong with effect from 5 May 2003. The Kyoto Protocol is directed at the reduction of four greenhouse gases (carbon dioxide, methane, nitrous oxide, sulphur hexafluoride) and two groups of gases (hydrofluorocarbons, perfluorocarbons). [1]

Legislation regarding the control of greenhouse gases in HK

The six greenhouse gases dealt with in the Kyoto Protocol are not referred to in any air pollution legislation in HK. [2] However, carbon dioxide and methane are excluded from the definition of “volatile organic compound” under the Air Pollution Control (Volatile Organic Compounds) Regulation (Cap 311W), whilst perfluorocarbons are mentioned in the definition of ‘exempt compound’ in the Schedules to those Regulations.

Despite the Kyoto Protocol coming into force on 16 February 2005, it does not appear that any reference is made to the Protocol in the laws of Hong Kong. [3]

Greenhouse gases in Hong Kong and China

Hong Kong should focus on CO2 emissions from buildings and not just vehicles and power plants. In 2004, CO2 accounted for more than 99% of greenhouse gas emissions by weight, and in excess of 85% of global-warming potential in Hong Kong. [4]

Methane (CH4) came second and accounted for more than 11% of the warming potential. [4]

Other greenhouse gases commonly found in Hong Kong are nitrous oxides (NOx), hydrofluorocarbons, perfluorocarbons (PFCs) and sulphur hexafluoride (SF6). [4]

Methane is 60 times more potent at capturing heat energy than CO2, but lasts fewer years in the atmosphere. Nitrous oxide is 270 times more efficient at trapping heat than CO2, it is far rarer than methane but it lasts 150 years in the atmosphere. [4]

As China struggles to meet demand for electricity, it will inevitably burn more coal. If it concentrates too heavily on this form of power generation, it could well destabilise the Earth’s climate. Increasing efficiency of electricity generation, transmission and use will all become vital tools in the battle to combat climate change. [4]

Climate change and air pollution

According to the Intergovernmental Panel on Climate Change (IPPC), climate change is expected to contribute to some air quality problems such as an increase in respiratory disorders by warming-induced increases in the frequency of smog (ground-level ozone) events and particulate air pollution. [5]

Ramanathan and Feng (23 September 2008) estimate we have already committed the Earth to 2.4oC of warming, but have so far been spared much of the effect due to global dimming from air pollution. [6]

This effect is so important that they caution against too aggressively curtailing sulphur and nitrate air emissions. They argue for the need to keep these artificial atmospheric brown clouds in place for some time so that they will continue to provide a net cooling effect. [6]


  1. 1.0 1.1 Declaration 10, Kyoto Protocol; see also Status of Ratification, China (Endnote 2)
  2. ‘APCO – 101 A Review of the Air Pollution Control Ordinance’, Andrew Lawson, February 2009 – last accessed 11/8/10
  3. Introduction, Annotated Ordinances of Hong Kong, Air Pollution Control Ordinance (Cap 311), Antonio M. Da Roza, 2009, LexisNexis </font>
  4. 4.0 4.1 4.2 4.3 4.4 ‘Boomtown to gloomtown – The implications of inaction’, CLSA – Christine Loh, James Paterson, September 2006 – last accessed 11/8/10
  5. ‘Climate Change – Health and Environmental Effects’</u>], U.S. Environmental Protection Agency, 2009 – last accessed 11/8/10
  6. 6.0 6.1 ‘The Great Disconnect’, Bill Barron, December 2009 – last accessed 11/8/10