Chapter 1 - Why Can’t We Ignore Climate Change?
What’s The Big Deal If Our Climate Is Changing?
Many scientists have warned that climate change would lead to irreversible consequences to the world. Recently, students around the world were out on strikes to protest and demand actions on climate change. Nevertheless, some skeptics choose to disregard the projected impacts of climate change as scaremongering; some consider receding glaciers and habitat loss for polar bears of little relevance. They have been indifferent to climate change impacts, not to mention changing lifestyles to cope with it. In fact, the impacts of climate change are hitting increasingly close to home. From erratic weather patterns to the rising frequency of extreme events, all of us should be able to experience that climate change is already affecting every part of our lives, no one is spared.
Our lifestyles and consumption habits cause the rising temperatures globally. Therefore, all human beings need to bear the responsibilities for mitigating the impacts of climate change. According to the recent Special Report on Global Warming of 1.5°C of the Intergovernmental Panel on Climate Change (IPCC), it is evident that human-induced warming has already reached about 1°C above pre-industrial levels, and the warming rate is now about 0.2°C per decade. Temperatures greater than the global average has also already been experienced in many regions and seasons. Also, according to the Global Risks Report 2018 published by the World Economic Forum, extreme weather events such as storm surges, droughts and natural disasters have been identified as the top risks that pose a serious threat to global stability.
Globally, annual emissions of carbon dioxide (CO2) have risen dramatically over the past decades. With more CO2 accumulated in the atmosphere, the atmosphere traps more thermal energy on the Earth. The more carbon we pump into the atmosphere, the higher the average temperature of the planet will be, and we expect to see more frequent extreme weather events causing sustained and serious impacts on health, the economy and the environment.
Carbon emissions are sometimes used as a shorthand for referring to the emissions of CO2, or greenhouse gases (GHGs) in general. Strictly speaking, gases that absorb and trap heat on the planet are called GHGs. The main GHGs in the Earth’s atmosphere are CO2, methane (CH4), nitrous oxide (N2O) and ozone (O3).
CO2 is the most common GHGs emitted by human activities, in terms of the quantity released and the overall impact on global warming. They are mainly produced from the activities that involve the burning of fossil fuels (e.g. coal and natural gas), including electricity generation, travelling by car, ship and plane, etc. To facilitate the measurement and comparison, the emissions of different GHGs are converted to CO2-equivalent (CO2e)* based on GHG’s global warming potential.
Note: *CO2-equivalent (CO2e): A metric measure used to compare the emissions from various GHGs based upon their global warming potential (GWP). The CO2e for a gas is derived by multiplying the tonnes of the gas by the associated GWP.