Why is climate change happening?
Earth’s energy balancing act
Have you ever noticed that temperatures increase during the day when the sun is out, and decrease during the night? The energy came from the sun, but where did it disappear to when the sun went away? Out to space via electromagnetic radiation, just like the sun does! While the sun is very hot and cools itself by emitting radiation mainly in the visible spectrum that we can see, the Earth cools itself by emitting lower energy infrared radiation that we can’t see. If the earth didn’t cool itself off, it would just keep heating and heating as it receives continuous sunlight.
Try using an infrared camera at night and see this radiation for yourself!
The temperature of a star or a planet like Earth is an equilibrium, where the amount of energy inputs becomes equal to the amount of energy outputs. Unlike a star, the Earth does not generate much of its own heat and would be very cold without energy from the sun. So effectively the temperature of Earth is determined by a balance between the amount of heat absorbed from the sun and the amount of heat radiated to space. If anything were to disturb this balance, temperatures would shift.
What are greenhouse gases?
Greenhouse gases are molecules that absorb light in the infrared spectrum. Like how microwave ovens heat up water molecules by using microwave radiation, infrared radiation heats up greenhouse gases. In Earth’s atmosphere, greenhouse gases can absorb infrared radiation that Earth is emitting to cool itself. Reabsorbing this radiation that would have otherwise escaped to space prevents the energy from leaving the planet and increases Earth’s temperature.
Learn more about infrared radiation
Where are greenhouse gases coming from?
A lot of greenhouse gases in the atmosphere are naturally occurring. Without these naturally occurring greenhouse gases in the atmosphere, the average temperature of the Earth would be -18°C instead of 15°C. However, an increasing proportion of greenhouse gases in the atmosphere are from human caused sources. While there are several different molecules that are greenhouse gases, the primary ones that humans are responsible for releasing into the atmosphere are carbon dioxide and methane (also known as natural gas). As of 2021, the concentration of carbon dioxide in the atmosphere has increased since human industrialization by about 50% so far. This magnitude of increase far exceeds any amount that can be explained by known natural variations in carbon dioxide levels over long periods of time.
Most carbon dioxide emissions that humans are responsible for releasing into the atmosphere come from burning fossil fuels such as oil, natural gas and coal. These fuels are used to release energy for various purposes that benefit our society, from heating buildings, to transportation and industrial processes. Our society has grown so large and so globally connected that we would not be able to function without using energy anymore, so breaking this dependency on fossil fuels is a great challenge. Thankfully, other alternative energy sources to fossil fuels do exist, and these are continually becoming more economical, accessible, and popular.
For more on how greenhouse gases affect climate change:
Climate Change Atmospheric Carbon Dioxide
Causes and Effects Climate Change
Isn’t natural gas clean energy?
The answer to this question depends on what clean means to you. Relative to other fossil fuels, such as coal or diesel, natural gas is cleaner because it releases less carbon dioxide and less particulate matter for an equal amount of energy. Relative to hydroelectric power though, such as our electricity in Cranbrook, natural gas is much less clean as there is no particulate matter from using electricity, and the greenhouse gas emissions associated with the electrical system are dramatically lower.
There is an alternative to natural gas called renewable natural gas. Renewable natural gas is composed of methane, exactly like natural gas. The difference is that this methane is sourced from places such as landfills or some sewage treatment lagoons where it can be produced naturally as a biproduct of decomposition. Unfortunately, the quantity of renewable natural gas produced or that is expected to be possible to produce in the future is not sufficient to meet the natural gas demand in BC.
Learn more about renewable natural gas!
Learn about the expected demand for natural gas in BC!
Learn about the expected supply of renewable natural gas in BC!