Climate Change is complicated. The causes (drivers) are seeped into our everyday lives and thus solutions are proving elusive. But what are these drivers? What is actually leading to a warming world, and is it induced by human actions?
Greenhouse gases (hereby referred to as GHG) are leading to a warming of the planet which is leading to a plethora of undesirable outcomes for us and for all life on earth. These gases are acting like a blanket, trapping heat from the sun inside the earth’s atmosphere. This doesn’t just increase the planet’s temperature but also means more moisture (warmer air holds more water), meaning increased evaporation and precipitation and more extreme weather patterns. This is seen as increased water in some higher latitude and tropical regions but decreasing amounts in other areas, leading to wildfires, drought, food shortages and multitude of terrifying outcomes. This is where the shift from the term global warming to climate change occurred. Global warming is confusing, as the felt impact will often be expressed via increased rainfall and more intense weather events, including extreme cold.
The release of GHG (carbon dioxide is one of these, as are methane, nitrogen oxide, and fluorinated gases sometimes known as chlorofluorocarbons (CFCs)) occurs for many reasons. Principally this is through the burning of fossil fuels, but these gases are also released via the ploughing of soil, deforestation, ruminant (ie cattle) farming, landfill and natural gas operations. Our use of fossil fuels has risen exponentially in the past 150 years or so and I am not here to persuade anyone that this crises is human induced- the science has been clear on that for many years now.
Fundamentally, what we mean when we talk about climate change is this greenhouse effect, so what is this? It is easiest to consider when we actually imagine a greenhouse. The glass of a greenhouse traps the suns heat inside the internal space, increasing temperatures. Greenhouse gasses are acting like the glass. The earths systems act in a stunningly complex balance, which includes many way of these gases incorporating into the earths systems. Unfortunately, human activities are knocking these relationships out of balance, with too much GHG in the atmosphere to be safely incorporated back into the earths systems without disturbing the fine balance of organic life. The process of photosynthesis is one of the principal mechanisms on earth’s carbon balance sheet, as living organisms (from huge trees to minuscule phytoplankton) take in carbon and release oxygen. The oceans also take in enormous quantities of carbon dioxide, but there is a limit to the amount that is sustainable (ocean acidification occurs as a result excess CO2 in the water, initially threatening coral reefs but potentially all ocean life).
Since the late 1800’s the planets average temperature has increased by between 0.65-1.06°C and predictions for future rises in the next 100 years are around 0.3-4.8°C. Although this may not sound like a large temperature rise, the fine balance of earth systems means that certain knock-on effects may be sparked with just a small change in the earth average temperature, leading to feedback loops (more on these later) and runaway climate change (the point at which our positive actions are too late to stop the rising temperatures). This is not a desirable point to reach. Please hold in mind the absolutely vital fact that we do not know what planetary temperature rises above 2°C will do. It is absolutely possible that a rise of 4°C would make human life on earth impossible, and this is the temperature many scientists believe we are heading for.
Climate change, in its core meaning of global warming (I will expand this discussion to include often forgotten/ignored elements of human activity) is caused by how we use energy. This means that it is deeply constructed into all our ways of life, from shopping habits, food choices, travel, home energy and construction, our phones and clothes, basically everything we do to maintain modern lifestyles.