We looked at the science that proves just how real climate change is, but let’s explore a little deeper what is actually causing climate change.

In a stable climatic environment, with GHG emissions from natural occurrences and human activities (anthropogenic) sources, there is a balance between GHG’s (eg. CO2, methane etc) that are released and those that are absorbed or removed from the atmosphere through various physical, biological or chemical means. Carbon for example can be absorbed through carbon sinks such as plants, forests and soil or through technologies such as carbon capture, usage and storage (CCUS). The production of GHG’s comes primarily from the burning of fossil fuels and other industrial processes and secondly from land use for agriculture and livestock and deforestation [IPCC, 2014]. There is no doubt the Earth is paying for the rapid economic and industrial growth post WW2 and the more than tripling of the global population.

The problem right now is that not only is there is an imbalance between GHG’s produced and those absorbed but this has been happening for some time and is producing a continuing build-up of GHG’s. This will continue with disastrous consequences if no action is taken and is the reason behind the calls for targets to reduce emissions to net zero (by 2050 in the case of the Paris Agreement, adopted in 2015).

There are some natural climate cycles that can change the temperature of the Earth, but the changes we are seeing now are occurring at a scale and speed that natural cycles cannot explain. For example there are El Nino patterns that can change ocean temperatures and can affect global temperatures for a short amount of time (months or years) but cannot explain the persistent warming that we see today. Then there are longer-term changes like Milankovitch cycles and solar irradiance that take tens of thousands of years.

It is now scientifically irrefutable that human activity, such as burning fossil fuels and changing how we use the land, is the leading cause of climate change [IPCC].

Reference:

University of Cambridge – Institute for Sustainability Leadership “The state of climate change and the underlying science” 2021.

Met Office UK “Causes of Climate Change” 2020.

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