Question: How does climate change start?

Jeni Spragg answered on 10 Jun 2016:

Hi BrightSpark,

Oo, that’s a big question! (So I’m sorry for my big answer!)

When we talk about climate change, we usually mean ‘anthropogenic’ (or human-caused) climate change. The climate can change naturally without any interference from us, but now we know that human activities are causing drastic changes to the climate around the planet.

Humans cause climate change by releasing greenhouse gases into the atmosphere. These gases trap extra heat from the sun, making the planet gradually warm up. It’s good to have some greenhouse gases in the atmosphere to trap some heat, otherwise the Earth would be freezing cold. But humans are upsetting the natural balance of the planet by releasing far too much.

This is upsetting all the climate systems – we are not only getting warmer, but seeing more extreme weather events such as floods and droughts. This is why we call it ‘climate change’ and not just ‘global warming’ – it’s about more than just heating up (wouldn’t we all like a bit of a warmer summer?!). Sadly it’s beginning to happen already, with more and more of the severe weather events we see being linked to climate change.

The main greenhouse gas is carbon dioxide, which we release when we burn things (e.g. in our cars or power stations). There’s also methane (natural gas, released from fossil fuels or things that rot), nitrous oxide (released from some fertilizers and industrial processes) and some others. Carbon dioxide is not the most powerful greenhouse gas, but it is the most important, because we make so much of it.

Some people debate whether climate change is really happening, but unfortunately it’s not really up for debate any more. Some research found that 97% of experts on the subject are agreed on the fact that serious climate change is happening because of humans. If 97% of doctors told you a medicine was dangerous, would you believe them? So now scientists and engineers are trying to move on from questioning whether climate change is happening, to actually doing something about it. Fingers crossed we’ll manage it!