Kyoto Protocol greenhouse gases and the Canadian Environmental Protection Act: chapter 4

4. Conclusion

Given that:

  • the radiative properties of GHGs, and the role GHGs play in the energy balance of the Earth, are well established;
  • concentrations of atmospheric GHGs and their radiative forcings have generally increased over the 20th century as a result of human activities;
  • the Earth's climate system has demonstrably changed on both global and regional scales since the pre-industrial era, with some of these changes attributable to human activities, including human emissions of GHGs;
  • the global average surface temperature has increased over the 20th century by 0.6˚C (±-.2˚C)
  • most of the warming of the past 50 years is likely to have been due to increases in greenhouse gas concentrations;
  • the vulnerability of human societies and ecosystems to climate extremes is demonstrated by the damage, hardship and death caused by events such as droughts, floods, heat waves, avalanches, and storms, hurricanes and cyclones;
  • the general relationship between impacts and temperature change has been established;

and furthermore, given that:

  • the amount of future global warming will be dependent on the amount of greenhouse gases from human activity that are emitted in the future;
  • the projected warming for the 21st century is very likely to be without precedent during the last 10,000 years and sea level is projected to rise significantly;
  • the frequency and magnitude of many extreme climate events increase with a small temperature increase and will become greater at higher temperatures;
  • GHG forcing in the 21st century could set in motion large-scale, high-impact, non-linear, and potentially abrupt changes in physical and biological systems over the coming decades to millennia;
  • diversity in ecological systems will continue to be affected by climate change and sea-level rise in the future, with an increased risk of extinction for some species currently listed as "critically endangered" and of currently "endangered or vulnerable" species becoming even rarer in the 21st century;
  • there are threats to humans and ecosystems from an increase in sea level rise, extreme events and abrupt climate and ecological changes;
  • the Arctic region is extremely vulnerable to climate change, and major physical and ecological impacts are expected to appear rapidly there as warming in northern high latitudes is expected to be greater than the global average;
  • vector-borne diseases, including malaria and dengue fever, may expand their ranges in the United States and may develop in Canada; and
  • adverse impacts will become increasingly negative with increasing temperature:

It is proposed that greenhouse gases, including CO2, CH4, N2O, SF6, Hydrofluoroarbons and Perfluorocarbons, meet criterion b as set out in CEPA 1999 Section 64.

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