Climate Change is everywhere. Both physically and literally. When we aren’t reading or hearing about it in the news we are physically experiencing it.
But the buzzword is used so frequently it can become easy to forget exactly what it is and how it is defined. Hence why it is always important to revisit a simple climate change definition to establish the fundamentals about climate change.
Climate Change Definition
In truth, any climate change definition is scientific, long-winded, and actually quite difficult to understand quickly (see examples below). Instead, we want to create a universal definition of climate change so that it is understandable for all.
The leading authorities on climate change including the IPCC and the UNFCCC each define it slightly differently due to the fact that our climate changes both due to natural or human activity.
While the IPCC definition makes the distinction between ‘natural’ and ‘human’ changes to our climate, the UNFCCC definition explicitly states that climate change is a result of human intervention, which in turn causes changes in our climate contrary to what is typically expected.
When the term climate change is mentioned in the media, they are most likely referring to the UNFCCC definition, where human activity is primarily responsible for the rapid changes in our climate that we are witnessing.
Climate Change – A Simple Definition
Based on this information, one can define climate change as:
A change in our climate caused by human activity that alters the natural or average climate that is considered normal for our planet.
By defining climate so simply we miss an important aspect that climate change occurs thanks to both human (anthropogenic) influences as well as natural changes.
Therefore, it is very important that overly simplistic definitions like these are used carefully and only for foundational understanding.
Hence why the IPCC and UNFCC definitions are so long-winded:
Refers to a change in the state of the climate that can be identified (e.g. by using statistical tests) by changes in the mean and/or the variability of its properties, and that permits for an extended period, typically decades or longer. Climate change may be due to natural internal processes or external forcings such as modulations of the solar cycles, volcanic eruptions and persistent anthropogenic changes in the composition of the atmosphere or in land use – IPCC Climate Change Definition
A change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods – UNFCCC Climate change Definition
How our Climate Changes & A Brief History
As far back as the 19th century, scientists have been exploring the changes in the Earth’s atmosphere related to what we now term climate change.
One of the biggest breakthroughs was in 1896 when the Swedish chemist Svante Arrhenius discovered how reducing carbon dioxide levels (a common gas) in our atmosphere would also in turn reduce the average temperature of the planet.
At the time, he suggested that cutting carbon dioxide concentrations by half would cause an ice age. Conversely, doubling it would raise average global temperatures by up to 5℃.
Despite Arrhenius’s discoveries and numerous other scientific discoveries linking greenhouse gases with temperature changes and the natural cycles of ice ages, these theories were largely ignored and undervalued for half a century.
It was not until the 1950’s when climatologists used state of the art analysis and equipment to accurately measure greenhouse gases not only in the present but also in the past from ice cores in Greenland and Antarctica.
By understanding the changes in temperatures, the composition of our atmosphere and the concentrations of greenhouse gases in both the present and the past, these previously proposed theories of climate change became clearer and clearer.
Ultimately, the scientific advancements of the 20th century has allowed us to understand how our climate changes due to the impact of different greenhouse gases that move around our Earth system in their various forms.
That seems like quite a vague way of explaining things but it is really pivotal to understand that greenhouse gases can take various forms. As we have explored, one significant gas is carbon dioxide, one of the many greenhouse gases that dictate how warm or cold our planet is.
More carbon dioxide in our atmosphere acts like a greenhouse because it traps more sunlight (radiation) than normal, therefore heating our Earth. However, carbon dioxide can change forms.
Millions of species on our planet, such as plants and algae, use carbon dioxide to create oxygen (via photosynthesis). Therefore, it is important to consider that carbon dioxide is always present in our Earth – it just changes state during its lifetime.
In summary, the higher the concentration of greenhouse gases in our atmosphere, the warmer our planet.
But this does not mean we simply eradicate all greenhouse gases forever because these gases also sustain our planet too. Without the greenhouse effect of these gases, our planet would be too cold to inhabit and would be similar to the atmosphere of Mars.
It is thus important to find that sweet spot in terms of the amount of greenhouse gases in our atmosphere.
If you have made it this far I hope you have enjoyed reading ‘climate change definition’ and if you would like to know even more we have a host of articles going into the many aspects of climate change. Check them out here!
