Global Warming: A Universal Problem

Carbon Footprint of Healthcare

• Medical care accounts for a large proportion of emissions
• Carbon footprints stemming from healthcare are variable between countries
• Equivalent emissions as % of national emissions of CO₂
  • NHS (UK) ~ 3%
  • Australia ~ 7%
  • US ~ 10 %
• Anaesthetic gases contribute to the greenhouse effect as they influence radiative forcing

Radiative Forcing

• Radiative forcing is the change in energy flux in the atmosphere caused by natural and/or anthropogenic factors of climate change
• Radiative forcing is measured in watts/metre ²
• Energy is constantly flowing in, some is reflected back and the rest is absorbed by the earth
• The earth’s energy budget (inflow-outflow) largely determines climate
• There are 3 main factors for the earth’s energy budget
  • Solar irradiance (sunlight)
  • Albedo (indication of how well a surface reflects solar energy varies between 0-1)
  • Atmospheric composition (greenhouse gas, aerosols)
• Natural factors (climate cycles have occurred throughout Earth’s history)
  • changes in the sun’s energy output
  • changes in Earth’s orbital cycle
  • large volcanic eruptions (light-reflecting particles expelled into the upper atmosphere)
• Anthropogenic factors (human impact on Earth’s climate). Various components of the atmosphere have the effect of absorbing the reflected radiation
  • Carbon Dioxide
  • Methane
  • Halogens
  • Nitrous Oxide
  • Other gases
• Human expansion of the greenhouse effect is the principal cause of the current global warming trend

F-gases (Fluorocarbons)

• HFCs are members of a family of gases known as the F-gases (Fluorocarbons) along with CFCs and HCFCs
• HFCs have high global warming potential (GWP), raising concern about their impact as they become increasingly used as replacements for ozone-depleting substances (ODS)
• Regulation of F-gases is achieved with various international protocols and agreements

The Montreal Protocol 1987

• Agreement ratified by 197 parties has been in effect since 1989
• Aims to reduce the consumption of substances that deplete the ozone layer
• The Kigali agreement is the latest revision (in effect since 2021) that focuses on reducing Hydrofluorocarbons (HFCs) use by 85%
• Anaesthetic gases which are HFCs are currently not prescribed based on their medical necessity
• The Montreal Protocol has undergone 9 revisions since its implementation

Kyoto Protocol 1997

• This agreement ratified by 192 parties has been in effect since 2005
• Aims to reduce global warming by lowering greenhouse gas concentrations in the atmosphere
• Kyoto Protocol covers emissions of the six main greenhouse gases, namely:
  • Carbon dioxide
  • Methane
  • Nitrous oxide
  • Hydrofluorocarbons
  • Perfluorocarbons
  • Sulfur hexafluoride

Paris Agreement 2015

• This United Nations Climate Change Conference agreement between 196 parties has been in effect since 2016
• Aims to
  • Hold the increase in global average temperature to below 2 °C above pre-industrial levels and pursue efforts to limit the temperature increase to 1.5 °C above pre-industrial levels
  • Increase the ability to adapt to the adverse impacts of climate change and foster climate resilience and low greenhouse gas emissions development
  • Make finance flows consistent with a pathway towards low greenhouse gas emissions and climate-resilient development

Alternative to HFCs in anaesthesia

• TIVA
• Regional Anaesthesia
• Xenon

We will focus on the environmental benefits of TIVA